stroke in childhood

8/9/2019 Stroke in Childhood

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DOI: 10.1542/pir.17-8-2651996;17;265Pediatrics in Review

Michael J. Rivkin and Joseph J. VolpeStrokes in Children

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Print ISSN: 0191-9601.Village, Illinois, 60007. Copyright © 1996 by the American Academy of Pediatrics. All rights reserved.

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IM PO RTANT PO INTS

1 . S tro k e

occurs

at an an n u a l freq u en cy o f

2 .5 cases pe r 1 00 ,00 0 ch ild ren .

2 . S tro k e in ch ild ren is cau sed b y he art d ise ase, i nf ec ti on m et ab ol ic d is or

ders hemato log ic

d iso rde rs , an d vascu litic

d isord ers often d u e to a uto im

m u n e

processes.

3 . T h e th ree

processes

th at can cau se stro k e in ch ild ren a re

embol ism,

t hr om b o si s a n d h em o r rh a ge .

4 . A lth ou g h la teral ized f in d in gs m a y b e fo u n d o n n eu ro log ic ex am in ation in a

neo n ate w h o h as s uff er ed a s tr o ke focal se izu re m ay se rve as the sole

initial m an ifes ta tion of th is d iso rder in a n ew b orn .

5 .

M ag n etic reson an ce im a gin g p ro v id es n ot o n ly

bet ter

im a ge r es olu tio n

th a n com p u ted tom o grap h y b u t a lso is m u ch m ore

sensi t ive

t o s ub tl e

pa ren ch ym a l ch a n ges th at a cco m p a n y strok e

soo n afte r its occu rrence.

6 . A cu te la tera lized weakn es s in a ch ild does n o t a lw a ys in d icate th e occu r

ren ce of s trok e . C on d ition s tha t

produce

sym p to m s an d sign s s im ila r to

strok e in du d e T o d d p ostic ta l p ara lysis hemipare t ic se izures sub and

epidura l

he mo rrha ge , hyp og ly ce mia ,

a n d a lt er na ti ng

hemip leg ia

o f c h il dh o od .

*A ss ista n t P ro fessor o f N eu ro logy .

tB ronson C ro ther s P ro fes sor o f N euro lo gy ,

H arv ard M ed ica l Sc hoo l, B oston , M A .

P ed ia trics iv

i

Rev iew Vo l. /7 N o . 8 A ug ust 19 96

26 5

S tro k es in C h ild ren

M ichae l J . R ivk in M D and Joseph J . Vo lp e M D t

ART ICLE

S trok e den o te s the sudd en onse t o f a

foca l neu ro lo g ic de fic it an d m os t

o ften in clu des the ab ru p t appea ran ce

o f w eakness. In te rrup tio n o f b loo d

flow to a pa rt o f the cen tra l ne rv ous

system (CN S ) u sua lly un de rlie s th e

re su ltan t w eakn ess . B ecause m ost

strok es in ch ild ren are re la ted to foca l

ce reb ra l inv o lvem en t, th e m o st com -

m on c lin ica l m an ife sta tion is the

ab ru p t ap pearance o f hem ipa res is .

L ess frequen tly , th e cau se o f stro ke

invo lves th e b rain stem , ce rebe llum ,

o r sp ina l co rd . Th e fu nc tion al conse -

quences a lw ays ref lect the neuro -

ana tom ic featu re s o f the a ffec ted

CN S reg io n .

Ep idemio logy

Ch ildho od stro ke o ccurs w ith an

annu al inc iden ce of 2. 5 cases pe r

10 0 ,000 popu la tion an d has b een

rep orted in a ll rac ial and e thn ic

g rou ps. T he sequ e lae a re n o t tr iv ia l.

In add ition to la sting la tera lized

w eakn ess, cog n itive de ficits , d is tu r-

b an ces o f lan guage , v isua l d efic its ,

and se izu re s m ay pe rsis t long a fte r

the acu te even t h as co nc lud ed .

T he causes o f strok e in ch ild ren

d iffe r from tho se in adu lts . S trok e in

adu lts is as soc ia ted la rge ly w ith

h yp erten sion or a the ro sc lerosis an d

th e ir re spec tive hem o rrhag ic and

ischem ic co nsequ en ces. S troke in

ch ild ren m ore comm only is cau sed by

o r re lated to cong en ital h ea rt d isea se ,

in fec tion , m e tabo lic d iso rde rs , h em a-

to log ic d iath eses , an d vascu litic d is-

o rde rs , f req uen tly d ue to au to imm une

p rocesse s (T ab le 1 ) . N one the le ss ,

d esp ite the m o st th o ro ug h o f ev alu a-

tio ns, e tio log y escap es d etec tion in

app ro x im a te ly 3 0 o f th e ped ia tric

p atien ts in w hom s trok e occu rs .

Pa thogenes is

Is ch em ic in ju ry o f the b ra in o ccurs a s

a resu lt o f on e of th ree d ifferen t

m ech an ism s: em bo lism , th rom bosis ,

o r d im in ish ed system ic pe rfusio n .

Em bolic dam ag e to the b ra in o ccurs

w h en m a te ria l fo rm ed a t a s ite in the

vascu la r system prox im al to the b ra in

lodg es in a b loo d v essel, thu s b lock -

ing cereb ra l pe rfu sion . Em boli o rig i-

na te m ost com m on ly from the h ea rt,

ar is ing from a clo t o n ca rd iac cham -

be r w a lls o r from vege ta tions o n

va lve lea f lets . A rte ry -to -a rte ry em bo li

are com posed of a c lo t o r p la tele t

ag g reg ate s tha t o r ig ina te in vesse ls

p rox im al to the b rain b u t u ltim a te ly

com e to re st and to occ lude flow in

vesse ls c r itica l fo r cereb ral pe rfusio n .

Th rom bos is den o te s v ascu la r occ lu -

sion due to a localized process w ith in

a b lo od vesse l o r v essels . A lth ough

ath e roscle rosis u nde rlie s m ost th rom -

bo tic p ro cesses a ffec ting ad u lts , it is

no t a comm on cau se o f th rom bosis in

ch ild ren . L ocalized lum ena l c lo t fo r-

m a tion occu rs in po lycy th em ia o r in a

hyp e rcoagu lab le state . A lterna tive ly ,

an a tom ic abno rm alitie s m ay lead to

clo t fo rm a tion or m echan ical o bstruc -

tion , a s in f ib rom u scu la r dy sp la sia ,

ar te ritis , o r a r te r ial d issec tion .

If system ic p ressu re dec line s su ffi-

cien tly to com p rom ise ce reb ra l pe rfu -

s ion , the CN S m ay suffe r in ju ry d ue

to d im in ish ed system ic p e rfusion .

C ard iac pum p failu re (rela ted to co n-

g en ita l hea rt d isease and its su rg ical

repa ir) a s w e ll a s sy stem ic hy po ten -

sio n d ue to h ypovo lem ia a re com m on

causes o f hy po tens ive ce reb ra l

ischem ic in ju ry . O ften b ra in in ju ry is

m u ch m o re d iffuse in the con tex t o f

d im in ished ce reb ra l p erfu sion com -

p ared w ith the m ore focal in ju r ie s

cha rac te ris tic o f th rom bo tic and

em bo lic ce reb ra l ev en ts . C e reb ra l

ischem ia se rves a s th e fin al comm on

p athw ay lead ing to b ra in in ju ry irre -

spec tive o f w he the r an em bo lic ,

th rom bo tic , o r hy pop erfu sive m echa -

n ism h as caused th e s tro ke .

B o th th rom bo tic an d em bolic

strokes m ay be he ra ld ed b y th e o ccu r-

ren ce o f transien t isch em ic a ttacks

(T IA s) . T IA s a re b rief ep isodes o f

fo cal, non co nvu lsive neuro lo g ic

de ficit a ttrib u tab le to in te rrup tion of

cereb ral pe rfusio n . A s w ith stroke ,

the o nse t is ab ru p t, bu t a T IA ep iso de

lasts le ss th an 24 hou rs, and reco ve ry

is com p lete . A T IA freq uen tly p or-

tends th e subseq uen t o ccu rren ce o f a

stro ke and its re su ltan t fix ed de fic its .

H em orrh ag e o ccu rs w h en b lo od is

re leased in to the ex travascu la r

in trac ran ial o r in tra sp in al space. In

th is c ircum stan ce, foca l in ju ry o f

b ra in o r sp ina l tissu e occu rs a s a

re su lt o f bo th p re ssu re exe rted b y the

space-occupy ing m ass o f b loo d an d

hem orrh age -rela ted isch em ia . S uch

in ju ry m ay be exacerba ted b y the

dam ag ing e ffec ts on neural tissue o f

substances re lea sed in th e b lo od .

Ep id u ral and su bdu ra l h em orrh ag e

a re in trac ran ia l co llec tions o f b lo od

sep ara ted from brain pa ren chym a by

dura l o r arach no id m em bran es.

S u ba rachno id h em orrh ag e occurs

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3/16

T A B L E . Etiologies of Str ok e in C hildr en

26 6

Ped i a t r i c s

Review Vo l. 17 No. 8 Augu st 19 96

.

N U R O L O G Y

St rokos

Thrombosis

{ 1 4 9 }asc ular D ysplasias

-Moyamoya disease

-N eur ofibr om atosis type 1

-Fibromuscular dy splasia

-D issecting aneur ysm

-V asc ular m alform ations

#{149}asculopathy

-Sick le cell disease

-Radiation

-T ra u ma

Intraoral

Neck

#{149}asculitis

-Infec tion-mediated m ening itis

-V i ra l

and

postvir al causes

-Autoimmune-mediated

System ic lupus er ythem atosus

Polyarteritis

nodosum

Takay asu arte ritis

Henoch-S chOnlein purpura

Kaw asaki disease

#{149}asospasm

-M igra ine

I

-C ocaine use

-G lue sniff ing

-W asp/S corpion sting

#{149}ematologic

-H emoglobinopathies

Sick le cell disease

Sick le C disease

-Polycythemia

-Thrombocytosis

-Leukemia /Lymphoma

-Coagulopathy

P rotein S deficiency

Pr otein C deficiency

. A ntithr om bin I I I deficiency

L u pu s a nt icoa gu la nt

O ral contr aceptive use

w hen blood flow s out o f the intracra-

nial v ascular bed and onto the surface

o f the brain to adm ix w ith cere-

brospinal f luid in the subarachno id

space. Intracerebral hemorrhage

deno tes bleeding into the parenchyma

of the brain.

S tro k e in th e N e w b o rn

H Y P O X I C - I S C H E M I C

E N C E PH A L O PA T H Y (H I E )

B rain injury consequent to asphyx ia,

Pr egnancy and the

postpartum state

L-Asparaginase

D issem inat ed int ravascular

coagulation

{ 1 4 9 }etabolic

-Homocystinuria

-Fabry disease

-Sulf ite oxidase deficiency

-Pseudoxanthom a elasticum

-M ito chondrial diso rders

Embolus

{ 1 4 9 }ardiac D isease

-Congenital dis ease

A ortic stenos is

Mitral stenosis

V entricular septal de fec ts

Patent ductus ar ter iosus

Cyanotic congenital heart

disease

w it h r i gh t- to- lef t

shunt

-A cquir ed disease

Endocarditis

Cardiomyopathy

Atrial

myxoma

Arrhythmia

-Air embolus

-F at em bolus

Hemorrhage

#{149}ead T raum a

-Subdur al hem or rhage

-E pidur al hem or rhage

{ 1 4 9 }pontaneous Occurrence

-A rterio venous malformation

-R uptur ed aneur ysm

M y cotic aneur ysm

Saccular aneury sm

-Thrombocytopenia

-Hemophilia

-O ther bleeding diatheses

hypox ia, or ischem ia is an important

cause o f neonatal neuro log ic morbidi-

ty . Tissue oxygen defic iency is pre -

sum ed to underlie the neuro log ic

injury caused by hypox ic- ischem ic

insults . A sphyx ia denotes an impair-

m ent in g as ex change that results no t

only in a de fic it o f ox ygen in blo od

but also in an exces s o f carbon diox -

ide and, thereby , ac ido sis . Further,

sustained asphyx ia alm ost alw ays

results in hypotens ion and ischem ia,

consistent w ith the like ly predomi-

nant impo rtance of ischem ia as the

final common pathw ay to brain

injury.

Ev idenc e o f hy pox ic- isc he mic

injury to the neonatal nervous system

as a result o f asphyx ia is re flec ted by

a conste llatio n o f s igns that appear

early in the po stpartum period. This

conste llatio n constitute s the c linical

entity o f HIE. A lthough diffuse hypo -

tonia is the most frequently observed

mo tor de fic it found early in the

course o f neonatal HIE, patterns o f

w eakness may emerge by the end of

the first day of life that re f lec t the

distributio n of cerebral injury from a

generalized hypox ic - ischem ic insult.

Term infants may demonstrate a pat-

tern of parasag ittal cerebral injury

manife sted as quadriparesis w ith pre -

dom inant prox imal limb w eakness.

This pattern deriv es from ischemia in

the w atershed or parasag ittal reg ions

o f brain, w hich correspond to the bor-

der zones o f c irculation be tw een the

anterior and m iddle cerebral arterie s

and the m iddle and pos terior cerebral

arterie s . Pre term infants may mani-

fe st de ficits re flec ting periventricular

leukomalac ia. The resulting w eakness

occurs prim arily in the low er ex trem-

itie s due to perinatal ischem ic injury

of moto r fibers subserv ing the legs.

These fibers lie dorsal and lateral to

the ex ternal ang le s o f the lateral y en-

tric le s . In each o f these cases, c linical

features and cerebral neuropatho log ic

finding s sharing a bilateral distribu-

tion are found. How ev er, focal cere -

bral infarctio n-that s , stroke -does

occur in the new bo rn.

F O C A L C E R E BR A L I N F A R C T I O N I N

T H E T E R M N E O N A T E

Etiologies

The cause of cerebral infarc tion fre -

.

quently escapes detec tion among

infants w ho have not been subjected

to overt perinatal asphyx ia. Indeed, in

3 7 o f

5

1 reported cases o f neonatal

stroke (7 3%), a cause could not be

identif ied. Interes ting ly , a le ft hem i-

spheric lo catio n has been noted to be

most common; the reason for this

neuroanatom ic predilec tion has no t

been discovered. Embo lic or throm-

botic e tio lo g ie s have been recog -

nized. Emboli from the placenta may

lodge in cerebral vesse ls and cause

s troke . Further, it is possible that fea-

tures o f the no rmal new born’s heart,




4/16

N EU R OLOGY

S trok.s

O n ce str oke is su spec ted , d ia gn o stic effo r ts sh ou ld

con cen tr a te on ... d iscover in g th e u n der lyin g ca u se .

CC T a n d M R I pr ovide r a p id eviden ce o f in fa r c tion o r

h emo r r h a g e .

P ed ia tr ics in R ev iew Vo l. 1 7 N o . 8 Aug us t /9 96 2 67

such as a patent f oramen ovale, per-

m i t the transm ission of embol i i nto

the system ic arter ial ci rculati on

through right- to-l ef t shunts. Once in

the system ic arter ial tree, the embol i

ul timatel y may ram i f y in the cere-

brovascular bed and cause f ocal

i nf arcti on. I n addi ti on, congeni tal

heart defects involv ing r ight-to- l ef t

shunts through septal def ects or a

patent ductus arteriosus serve as set-

ti ngs for embol i c stroke in neonates.

A nother eti ology of neonatal stroke

is thrombosis. Thromboti c infarcti on

probably i s most common in the new -

born as a consequence of bacter ial

meningi ti s. Polycy them ia and i ts

resul tant hyperv i scosi ty can cause

abnormal i ti es of blood f low and even

thrombosis. A pprox imatel y I .5 of

neonates are polycy them ic, w i th new -

borns w ho are smal l for gestati onal

age being af fected most f requentl y .

M ost cases of polycy them ia are idio-

pathi c or due to acqui red abnormal i -

ti es of oxygen del i very such as

maternal smok ing . N onetheless,

polycy them ias bearing autosomal

dom inant or recessive inheri tance

patterns have been described.

Cerebral venous thrombosis may

cause f ocal i nf arcti on in the new born.

Cerebral veins conduct deoxygenated

blood f rom the parenchyma to the

dural sinus system . These sinuses-

the sagi ttal , straight, transverse, cay-

ernous, and petrous-convey the

blood to the jugular veins for return

to cardiopulmonary ci rculati on.

Thromboti c occlusion of f l ow any-

w here in these venous condui ts leads

to i schem ia and sometimes inf arcti on,

usual l y hemorrhagic. I nf ecti on, dehy -

drati on, polycy them ia, congeni tal

heart di sease, and protein C def i cien-

cy al l have been impl i cated as causes

of cerebral venous thrombosis in

neonates; how ever, no def ini ti ve

cause need be found.

I ntracranial hemorrhage occurs in

neonates in one of f our neuroanatom-

i c di str i buti ons: subdural SD H , sub-

arachnoid SA H , intraparenchymal

I PH , or intraventri cular IV H . SD H

occurs more commonly in the term

inf ant; the other three types of hemor-

rhage are more common in preterm

inf ants. SD H in neonates appears to

resul t primari l y f rom mechanical

trauma. Cephalopelv i c di sproporti on,

ri gidi ty of the bony pelv i s, prolonged

duration of labor, unusual presenta-

ti ons, or the need f or prolonged

manipulati on or f orceps appl i cati on

may generate increased f orces on the

fetal head and predispose the inf ant to

SD H . Shear ing for ces may cr eate

tears in the vein of Galen or superf i -

cial cerebral veins. I f f orces are

ex treme, tears at the junction of fal x

and tentor ium can generate large sub-

dural blood col l ecti ons in the rela-

ti v ely smal l posterior fossa, culm inat-

i ng in brain stem compression and

cerebel l ar tonsi l l ar herniati on.

Smal ler tentor ial tears are relati v el y

common. W i th improved obstetr i c

practi ce, the incidence of SD H has

decl ined steadi ly .

B lood can occupy the subarachnoid

space in tw o w ays. Fi rst, i t may reach

the space af ter hemorrhage has

occurred in the cerebral parenchyma

or in the peri ventr i cular region.

Second, SA H may resul t f rom disrup-

ti on of the superf i cial l eptomeningeal

arter ies or of the f ragi l e vessels that

bridge the subarachnoid space; di s-

ruption of ei ther vascular structure

leads to di rect bleeding into the

space, so-cal l ed pr imary SA H . Prim -

ary SA H commonly occurs af ter

hypox ic-i schem ic brain insul ts and

af ter f etal head trauma. O f ten the

pathogenesis i s unclear.

I PH in the absence of I V H occurs

most commonly in term inf ants.

H emorrhage into the parenchyma of

the cerebral hem ispheres can be due

to head trauma, vascular mal forma-

ti on, coagulopathy , tumor, or inf arc-

ti on. Even though v i tam in K , a car-

boxy lati ng and acti vati ng agent f or

clotti ng f actors I I , V I I , I X , and X I , i s

adm inistered routinel y to new borns,

i ts def i ciency should be considered in

breastf eeding f ul l -term neonates w ho

present w i th intracranial hemorrhage.

In the absence of recognized coagula-

ti on or anatom ic abnormal i ti es, cere-

bral hem ispheri c I PH usual l y i s a

mani f estati on of hemorrhagic inf arc-

ti on. I n thi s ci rcumstance, embol i c

stroke precedes hemorrhage. W hen

the embol i c material occluding the

cerebral vessel eventual l y f ragments,

parti al or total perfusion through the

prev iously occluded vessel i s reestab-

l i shed. H emorrhage ensues as blood

escapes through the vascular w al l s,

w hich have been w eakened by the

embolus-induced ischem ia.

C linical F eatur es

Focal seizures have been identi f i ed as

the most common cl ini cal f eature

indicating the presence of stroke in

the ful l -term nonasphyx iated infant.

A l though lateral i zed f indings may be

found on neurologic exam ination,

they need not be present as hal lmarks

of cerebral i nfarcti on. Further, dim in-

i shed movement of ex trem i ti es on the

side of the focal sei zure may repre-

sent a T odd posti ctal paral ysi s rather

than paresis f rom upper motor neuron

injury due to cerebral i nfarcti on.

Recognizing focal sei zure as a mani -

f estati on of cerebral i nf arcti on i s

important because thi s may be the

only sign of the cerebrovascular

event; i ni ti al l y , other neurologic signs

may be absent.

C l i ni cal f eatures of SD H depend

on the location and size of the hemor-

rhage. T entor ial l acerati on can cause

stupor or even coma. Pupi l l ary and

ex traocular movement abnormal i ti es

are common. Retrocol l i s or opistho-

tonus is seen. Final l y , abnormal i ti es

of respi ratory pattern, such as

apneusti c or atax i c respi rati ons, are

ev ident and signi f y imm inent respi ra-

tory arrest. L ess severe SD H in the

poster ior fossa evolves more slow ly

and causes less severe brainstem dys-

function. Subdural col l ecti ons of

blood over the cerebral surfaces due

to tears of superf i cial cerebral veins

may be asymptomati c or accompa-

nied only by i rri tabi l i ty . I f the col l ec-

ti on i s suf f i cientl y large or accompa-

nied by cerebral contusion, seizures

can occur. G reater pressure, w i th

transtentorial herniati on, may di l ate

pupi l s uni l ateral l y and ablate pupi l -




5/16

I n neonates focal seizures rather than lateralized

neurologic findings are the most common clinical

feature of a stroke

26 8

P e dia tric s in Review Vol 7 No 8 Aug ust 9 96

N U RO LOGY

S t ro k e s

l ary l i ght responses. H ow ever, SD H

may escape diagnosis in the f i rst few

w eeks of l i f e and appear later as a

chronic subdural ef f usion. Such an

occurrence is marked by a rapidl y

enlarging head ci rcum ference and

increased transi l l um ination of the

skul l . C l i ni cal l y , m i ld SA H occurs as

an occul t phenomenon w i th few , i f

any , mani f estati ons. G reater amounts

of blood col l ecti ng over the convex i -

ti es may resul t i n seizures.

Diagnosis

Once stroke is suspected, electroen-

cephalography EEG and neuro-

imaging are the most usef ul methods

of documenting its occur r ence. I f

f ocal sei zures herald f ocal cerebral

i nf arcti on, the EEG of ten is the f i rst

diagnosti c test ordered. Ev idence of

local i zed brain dysf unction on EEG

consists of focal , persi stent vol tage

reduction or marked focal slow ing

and sharp w ave acti v i ty . Per iodi c lat-

eral i zed epi l epti form discharges may

be present. I n some instances, there

may be electrographic ev idence of

cl i ni cal l y observed seizures. Each of

these f indings may ex ist w hi l e the

E E G r emains r elatively less affected

over other regions of the brain.

The areas of electri cal abnormal i ty

should correspond to the af fected

areas of brain revealed by neuroimag-

ing. Cranial computed tomography

C CT dem onstr ates a low-density

region that eventual l y evolves to atro-

phy . H ow ever, ear ly in the period f ol -

l ow ing infarcti on, the af f ected cere-

bral terri tory may not be w el l v i sual -

i zed w i th CCT . M agneti c resonance

imaging M RI perm its identi f icati on

of cerebral i nf arcti on earl y af ter i ts

occurrence. M RI w i l l demonstrate

low or i sointense signal i ntensi ty on

T l -w eighted images and high signal

i ntensi ty on T 2-w eighted images

because of increased w ater content in

the infarcted region. D i f f usion-

w eighted M RI i s most sensi ti ve in the

f i rst hours af ter the event. Final l y ,

i ntracranial bleeding can be identi f i ed

easi l y w i th ei ther CCT or M RI .

O ther laboratory tests should

include hematocr i t and hemoglobin

electrophoresi s i f pol ycy them ia is

suspected. Screening for inf ecti ous

and metabol i c di sorders as w el l as

coagulopathies that could ref l ect

thromboti c or embol ic stroke should

be perf or med. E chocardi ogr aphi c

exam ination of the heart, especial l y

employ ing bubble contrast, w i l l help

identi f y a structural def ect that may

have contri buted to a new ly identi f i ed

embol i c cerebral infarct.

Treatment

T reatment i s supporti v e and sympto-

mati c. A nti convulsants are given i f

sei zures have occurred. Phenobarbi tal

i s the pref erred drug and is adm inis-

tered as a loading dose of 20 mg/kg.

D oses of 3 to 4 mg/kg dai ly are suf f i -

cient f or maintenance therapy .

A ttention should be given to hydra-

ti on state, acid-base balance, and

hematocri t and any def i ci ts corrected.

U nderl y ing inf ecti ous or metabol i c

condi ti ons or coagulopathy must be

treated. I diopathi c cerebral venous

thrombosis does not appear to requi re

anti coagulati on. Infants w ho have

suf f ered intracranial hemorrhage

should be evaluated neurosurgi cal l y

to determ ine the need f or clot evacua-

ti on or vascular repai r .

Prognosis

I t i s di f f i cul t to estimate the develop-

mental outcome f ol l ow ing cerebral

i nf arcti on. The periods of f ol l ow -up

reported in ser ies of neonatal stroke

have been highly variable. A lthough

seizures f requentl y abate over time,

chronic motor def i ci ts of ten become

apparent. M RI ev idence of cerebral

i nf arcti on may be helpf ul i n deter-

m ining the prognosis. M ost infants

w ho have ev idence of marked w hi te

m atter dam age or cy sti c/m ul ti cysti c

encephalomalacia have proven to

have neurodevelopmental abnormal i -

ti es on short- term f ol l ow -up. I nf ants

w hose CCT studies are normal

demonstrate l i ttl e or no neurologic

def i ci t w hen studied in fol l ow -up.

T hose inf ants demonstrating marked

parenchymal hypodensi ty or hemor-

rhage rarel y have normal develop-

ment during fol l ow -up. L ong-term

f ol l ow -up of inf ants w ho had cerebral

i njury identi f i ed by M RI shortl y af ter

bi rth i s sti l l needed. I n the case of

idiopathi c cerebral venous thrombosis,

al though f ol l ow -up has been l im i ted,

neurologic prognosis appears good.

S t r o k e in h ild r e n O ld e r

Th a n I Ye a r

D espi te the inf requency of stroke

among chi l dren, a great variety of eti -

ologies ex ists. T hese may be grouped

according to w hether an embol i c,

thromboti c, or hemorrhagic event has

occurred Table 1 .

T H R O M B O S I S

V ascular D ysplasia

M oyamoya syndrome is observed

most commonly in chi l dren younger

than 15 years w ho typical l y present

w i th T IA s or f i x ed motor def i ci ts of

sudden onset. Progressive narrow ing

and occlusion of the intracranial supra-

cl i noid internal caroti d arter ies are

characteri sti c. Endothel i al prol i f era-

ti on, f i brosi s, and intimal thi ckening

consti tute the vascular pathology .

Resul tant prol i f erati on of col l ateral

vessels, pr incipal l y f rom the ex ternal

caroti d ci rculati on, creates an intr i -

cate latti cew ork of compensatory

blood f low . The character i sti c appear-

ance on angiography is a f ine vascular

netw ork in the region of the basal

gangl i a Fig. 1 . I t i s f rom this

appearance that Japanese physicians

coined the term “ moyamoya,” mean-

ing “ something hazy l i ke a puf f of

cigarette smoke dri f ti ng in the ai r .”

Chi l dren usual l y present w i th acute

hem iplegia due to uncompensated

occlusion of the internal caroti d

artery . B ecause the anatom ic abnor-

mal i ty i s of ten bi l ateral , bi l ateral

motor def i ci ts may be f ound. In addi -

ti on, f i ne motor f unction may be

observed. Chorea has been reported

in associati on w i th moyamoya syn-

drome. A l though the vascular abnor-

mal i ty may be congeni tal , moyamoya

syndrome can occur as a sequel to a

pr imary disorder causing internal

caroti d artery occlusion. I t has been

found in chi l dren w ho have sick le

cel l di sease, neu rof i br om at osi s,

tuberculous meningi ti s, and f ibro-

muscular dysplasia. Ev idence sug-

gesting a heredi tary etiology in some




6/16


7/16

NEUROLOGY

Strokes

ic s tro ke .

T A B L E 2 . A u t o im m u n e D iso r d er s A ssoc ia t ed W it h

C e n t r a l

Nerv ou s

S yst em I n vo lv em en t

F

DISORDER

N S M N IF ES T TIO N S

System ic lu pus e ry them atosus

M igra ine headache , se izu re s,

F

strok e, ce rebe lla r d ysfunc tion ,

tran sve rse m ye lop ath y , a sep tic

men ing i t is

M ix ed con n ec t iv e t issu e d isease S e iz u r e s, s t r ok e, ce r eb e lla r d y s-

f u n c t i o n , t r igeminal n e u r o p a t h y

Po lya rte r itis nod osum M igrain e h ead ach e , s t r ok e , su b -

a rachn o id h em orrhag e, se izu re s

W e gen er gr an u lom a to sis M igrain e headache , su ba rachn o id

h em orrhage , s troke

Takay asu a rter itis

S eiz u re , s t r o k e

Heno ch -S ch { 246}n le in pu rp ura H eadache , s tro ke , s eizu re s, cho rea

270

Pediatr i cs i n Review Vol 17 No 8 August 1996

m otor lo ng trac ts co urse th rou gh the

b rain s tem , sym ptom s of gene ral s en -

so rim o to r im pa irm en t m ay b e found

as w e ll. V e rteb ra l a rte ry in ju ry in

ch ild ren has been reported in the set-

ting o f ath letic s (eg , ju do ), au tom o -

b ile accid en ts , o r ch iro p rac tic cerv i-

ca l sp ine m an ip u la tion . T he resu ltan t

v erteb robasila r s trok es a re d ue to

th rom bo sis o r to ve rteb ra l a rte ry d is-

s ec tion . A n ticoagu la tion w ith

an tip late le t agen ts has b een p ro posed

as the rapy . F ina lly , c ran ial rad ia tion

th erapy rece ived as p a rt o f can cer

the rapy m ay indu ce an o cc lus ive vas-

cu lopa th y lead in g to focal cereb ra l

isch em ia. B asa l gang lia frequen tly

are a ffec ted by th is v ascu lopa thy ,

re su ltin g in ex trapyram ida l m ov e-

m en t d ysfun ctio n , su ch as cho reo -

athetosis .

Vascu l i t i s

In fectio n is an im portan t and treat-

ab le cause o f stroke in ch ild ren .

C e reb ral vesse ls m ay becom e

in flam ed in the cou rse o f bac te ria l

m en ing itis . T h e sub arachno id a rte r ie s

becom e imm ersed in puru len t exu -

da te, and sm alle r v esse ls a re affec ted

as ex uda te m oves dow n V irchow -

R ob in spaces. The v es sel w a lls o f

ar te rie s and ve ins are a ffected by the

in flamm ato ry p rocess, and occ lusio n

of e ithe r can re su lt in s tro ke . A n ti-

b io tic s com bin ed w ith ste ro ids early

in th e course o f trea tm en t a re the co r-

ne rsto ne of the rap y . V ira l in fec tion

also m ay prom ote vascu la r in flam m a-

tion tha t m ay invo lve th e cereb ral

v es sels and cu lm ina te in strok e.

C e reb ral vascu litis and stroke h as

been d escribed in assoc iatio n w ith

hum an im m unode fic iency v iru s

H IV in fec t ion in ch ild ren .

Aneu ry sm s hav e been ob se rv ed in

asso cia tio n w ith the H I V -asso cia ted

v ascu litis . In add ition , he rp es zoste r

an d va rice lla v iruse s h ave b een asso -

cia ted w ith ang iitis o f the CN S ,

re su ltin g in acu te hem ip leg ia .

V ascu litis lead ing to a rter ia l occ lu -

s io n a lso has b een o bse rv ed in rub ella

and coxsack iev irus A 9 in fectio ns,

p ro bab ly as a po stv iral im m uno log ic

phenom enon . H ow eve r, v ascu litis

an d in fa rctio n have b een obse rved in

the po stv iral synd rom e o f acu te

n ec ro tiz ing h em orrh ag ic

leukoencephalopathy .

A u to imm une d iso rde rs o ften

inc lu de v ascu litis tha t m ay invo lve

th e CNS (T ab le 2 ). S ym ptom s o f

ab rup t onse t w ith accom pany ing

d efic its re fe rab le to the CN S lo ng

h av e been assoc ia ted w ith system ic

lup us ery th em ato sus (SLE ). A CN S

vascu litis had b een p re sum ed to

u nde rlie th e CN S m anife sta tions o f

S L E , b u t au t op sy st u d y o f p a t ien t s

su ffe rin g from SLE revea led a v ir tua l

absen ce o f ce reb rovascu la r in f lam m a-

tio n . R ath er , sm a ll a rea s o f in fa rc tion

re late to p ro life rativ e changes in ce re-

b ra l a r ter io le s , le ad ing to lum ena l

o cc lu sion . L arge a reas o f in fa rctio n

m ore like ly a re rela ted to lup us an ti-

coag u lan t-d e rived th rom bo em bo lism

o r to em bo lism from th e s ter ile car-

d iac v alv e lea fle t vege ta tion s assoc i-

a ted w ith SLE .

S trok e m ay occur in th e co urse o f

p o lya rter itis no dosa ; invo lvem en t o f

th e CN S is fo un d in 2 0 to 40 of

p atien ts . M ixed co nnec tive tissu e d is-

ea se (M CTD ), w h ich o ve rlaps clin i-

ca lly w ith po lym yo sitis , lu pu s, and

p ro gress ive sy stem ic sc le ro sis , can

in vo lv e the CN S. C ran ia l neu rop ath y ,

m ost comm only tr igem ina l ne rve

d ysfunc tio n , has been the d efic it cited

m ost freq uen tly . R ecen tly , how ev er ,

s trok e m an ife sting as sud den onset

h em ipa re sis an d aphasia has b een

reported in ch ild ren aff licted w ith

M C T D . T a k ay a su ar t e r it is , in v o lv in g

th e ao rta an d its p r inc ipa l b ranches,

h as been as soc ia ted w ith th rom bo tic

s trok e . In flamm atio n -in du ced lum e-

n al co nstr ictio n lead in g to th rom bosis

is th ough t to cause cereb ra l isch em ia

in these ch ild ren . A ng io g rap h ic

im p ro vem en t o f vessels in the ca ro tid

tree is o bse rved w ith imm uno sup -

p re ssiv e treatm en t. N ec ro tizin g arte ri-

tis w ith in f lam m ato ry in f iltra te h as

b een fo und in b o th m en in geal an d

ce reb ra l vesse ls o f ch ild ren su ffe rin g

from H eno ch -S ch { 246}n le in purpu ra .

B o th fixed and tran sien t de fic its

(T IA s) m ay occu r in th is d iso rde r.

T rea tm en t w ith ste ro ids o r o the r

im m unosuppres sive agen ts p rov e

m ost h e lp fu l. L ong-te rm an ticoagu la-

tio n h as no t been stu d ied . N euro lo g ic

com plica tions accom pany K aw asak i

d isease in I o f cases . H em ip leg ia

and se izu re s h av e been rep orted .

C hanges ind ica tive o f foca l ce reb ra l

in fa rc tio n h av e b een obse rved on c ra -

n ial C T stu d ie s . F in ally , th e CN S m ay

b e in vo lv ed in ch ild ren w ho h av e

h em oly tic -u rem ic synd rom e (H US );

en ceph a lo pa thy is fou nd in 20 .

S troke accom pan ied b y rad iog raph ic

ev idence of foca l CN S in ju ry h as

b een o bse rv ed in 5 o f ch ild ren w ho

h av e HU S . Focal in fa rc tion is foun d

p rim arily in the ce reb ra l h em isphe re

and basa l gang lia . E n do th elia l cell

dam age due to the Sh ig a tox in p ro -

duced by the cau sativ e

Eschericia

col i 0157: H7 organ ism is tho ugh t to

ac tiva te p late le ts an d coagu latio n cas-

cades, cu lm ina ting in th rom boem bol-

Vaso sp asm

S troke m ay occur in th e se tting of

m ig rain e headach e . T he occurrence




8/16

NEUROLOGY

Stroke s

Acu te h em ip leg ia m a y fo llow a g en er a lized se izu r e

T odd pa r a lysis . T h ese a r e sh o r t-lived . P r ese r va tio n o f

con sc iou sn ess is n o t a fe a tu r e o f gen er a lized se izu r es .

Pediatrics

in R ev ie w

Vo l. 17 N o . 8 A ugu st 1 99 6

27 1

of f ocal motor def i ci ts during a

m igraine headache denotes compl i -

cated m igrai ne . A c ut e hem ipar esi s

has been w el l -documented during

these episodes and is bel i eved to

ref l ect the involvement of the cere-

bral ci rculati on deri ved f rom the

carotid artery . Symptoms such as

atax ia, corti cal bl i ndness, and cranial

nerve dysf unction correlate w i th

involvement of the vertebrobasi l ar

ci rculati on. Focal symptoms may be

f i xed or may occur as T IA s. Ini ti al l y ,

an associati on betw een m igrainous

stroke and discharged embol i f rom

m i tral val ve prolapse w as hypothe-

si zed, but recent studies have not sup-

ported thi s theory . A l though oral con-

tracepti ves are associated w i th hyper-

coagulabi l i ty , w hich i s thought to pre-

di spose to stroke, the postulated addi -

ti ve r i sk f or stroke in m igraine

headache among those tak ing oral

contracepti v es has been chal l enged.

A ngiographic studies in patients suf -

fer ing f ocal def i ci ts consistent w i th

stroke in the setti ng of m igraine

headache have documented vasocon-

stri cti on of vessels in ei ther the verte-

brobasi l ar or caroti d ci rculati ons. I n

these cases, the neuroanatom ic posi -

ti on of the constr i cted vessels corre-

lated w i th the location of the

observed def i ci ts. A s a resul t,

i schem ia provoked by vasoconstr i c-

ti on during prolonged m igraine has

been hypothesized as the mechanism

of stroke in these patients. Calcium

channel blockers have been used f or

treatment, but def ini ti ve studies of

thei r ef f i cacy are needed.

D rug abuse may promote throm-

boti c stroke. Cerebral i nf arcti on and

peripheral neuropathy have been

associated w i th glue sni f f i ng in chi l -

dren, and cerebral i nfarcti on and

SA H have been observed af ter

cocaine use. Cocaine blocks the reup-

take of catecholam ines at the synapti c

clef t. T he resul ti ng elevated synapti c

concentrati ons of epinephrine and

norepinephrine markedly enhance the

neural acti v i ty of adrenergi c systems.

Tachycardia, hypertension, and vaso-

constr i ction resul t. T he probabi l i ty of

SA H is higher among cocaine users

w ho have occul t i ntracranial aneur-

y sms or arteriovenous mal formations

than among those w ho have normal

cerebral vasculature. T he resul tant

sudden ri se in system ic blood pres-

sure i s thought to precipi tate SA H .

I schem ic lesions also have been

f ound in patients w ho have used

cocaine. Y et, the associati on of these

ischem ic strokes w i th cocaine use is

less clear. The appl i cati on of cocaine

di rectl y to the vasculature of animals

has caused m ark ed vasoconstri cti on,

w hich f avors vasoconstr i cti on as the

underl y ing etiology of i schem ic

stroke af ter cocaine use. N onetheless,

i ntracranial hemorrhage appears to

occur more commonly than ischem ic

inf arcti on among those using cocaine.

T reatm ent i s supporti ve.

H em atol ogi c Eti ol ogi es

Several di sorders of coagulati on can

lead to embol i c or thromboti c stroke.

A dverse consequences of antiphos-

phol i pid antibodies have been identi -

f l ed in al l age groups. H ow ever, chi l -

dren, adolescents, and young adul ts

mani fest the cerebrovascular conse-

quences of these antibodies most

of ten. A ntiphosphol ipid antibodies

are poly clonal antibodies f ound in

serum that can bind to both neutral

and negati vel y charged phospho-

l i pids. The best studied are the lupus

anti coagulant L AC and anti cardio-

l i pin antibodies aCL . T hese anti -

bodies f i rst w ere associated w i th

thromboti c or embol i c cerebrovascu-

lar events among patients w ho have

SL E. Subsequentl y , patients suf fer ing

stroke w ho had no ev idence of under-

l y ing immune-mediated i l l ness other

than the L A C or aCL antibody w ere

f ound. The antibody prolongs the par-

ti al thromboplasti n time PT T in

v i tro, but acts as a procoagulant in

v i v o. T he mechanism by w hich

thrombosis or embol i sm occurs i s

sti l l unclear, but the presence of these

antibodies in a patient w ho also

smokes cigarettes has a posi ti ve anti -

nuclear antibody test, or suf fers f rom

hyperl i pidem ia may impart a higher

r i sk for stroke than i f the patient car-

r i es the antibody alone. The anti -

body ’ s presence is indicated by a pro-

longed PTT and a f al se-posi ti ve

serum V D RL ; i t can be demonstrated

conclusi vel y both functional l y and

immunological l y . The most common

location f or arter ial thrombosis

among chi l dren w ho have antiphos-

phol i pid antibody is the cerebral ci r-

culati on. Cerebral i nf arcti on and

T IA s are neurologic mani f estati ons

observed most f requentl y . T herapy

for patients w ho have antiphospho-

l i pid antibodies and have suf fered

stroke has not been substantiated

ful l y by random ized prospecti v e

study , but low -dose anti coagulati on

has been adv ocated.

A n absence of speci f i c serum pro-

teins that act as inhibi tors of coagula-

ti on may lead to stroke in chi l dren.

D ef i ciencies of tw o of these proteins,

protein S and protein C, have been

associated w i th thromboti c or embol -

i c cerebrovascular di sease in the

young. Protein C and i ts cofactor pro-

tein S act as anti coagulants and syn-

ergi sti cal l y attenuate coagulati on by

deacti vati ng the acti v ated f orms of

f actors V and V I I I . A bsence of ei ther

of these proteins w i l l ti p the scale of

balanced coagulati on tow ard

increased spontaneous clotti ng, w hich

can resul t i n stroke. A nti thrombin-I II

opposes the action of the acti vated

f orms of f actors I I , IX , X , X I , and X I I

through the i rreversible formation of

inacti vati ng complexes w i th these

f actors. D ef i ciencies of proteins S or

C or of anti thrombin I I I may cause

arter ial thromboti c or embol i c stroke

or venous inf arcti on. A l though these

def i ciencies of ten are congeni tal , they

may be acqui red through l i ver di sease

or the nephroti c syndrome. Screening

tests, i ncluding PT , PiT , and speci f i c

immunologic and f unctional testi ng

f or the proteins suspected of being

def i cient, i s essential f or diagnosis.

M al ignancies and thei r treatment

may predispose chi l dren to cerebro-

vascular i schem ic events. Promyelo-

cy ti c leukem ia and i ts treatment can

provoke dissem inated intravascular

coagulati on, l eading to stroke.

L ymphoreti cular cancers more than

sol i d tumors have been l inked to

thromboti c and embol i c strokes. T IA s

fol l ow ing induction chemotherapy f or




9/16

N E U R O t Y

.

a 9-yea r -o ld boy tr ea ted w ith L-a sp a r a g i-

na se fo r a cu te lymphocytic leukemia who

exper ienced new hea da che , se izu r es , a n d

le tha r gy. Br igh t sig na l in the supe r io r

sa g it ta l sinus la r ge a r r owhea d s a nd in

th e str a ig h t sinus sma ll a r r owhea ds

d eno tes L-a spa r a g ina se- ind uced cer ebr a l

venou s th r ombo sis.

Homocys t inur ia

Fabry d isease

S ick le ce ll d isease

Fibrom uscu lar dy sp lasia

Hemorrhage

Factor V if i d ef ic ien cy

Fac tor L X de f ic iency

Fac tor X I de f ic iency

Fam ilial in tracranial an eu ry sm s

S ick le ce ll d isease

Fam ilial cav ernou s angio m a

U n k n o w n

M echanism

27 2

Ped i a t r i c s in Review Vo l. 1 7 No. 8 Augu st 19 96

acu te ly m ph oblastic leu k em ia h av e

been repo rted . In addition , dural s inus

and cerebral v en ou s th ro m bo sis hav e

been fo und af ter th erapy w ith L -

asparag inase (Fig . 2 ).

O ral con tracep tiv es h av e been

assoc iated w ith stro k e in y ou ng

w om en. In so m e series, th e co m bin a-

tion o f m ig raine head ach e and co n-

curren t o ral co n tracep tiv e u se has

been cited as a risk fac tor f or strok e

(see earlier d iscussion). Pregnan cy

and the pos tp artum s tate hav e been

cons idered perio ds o f hy percoag ul-

ab ility . In add ition , v eno us stasis

increases. T hese tw o fac tors are

be liev ed to prom o te th e occu rrence o f

cerebral v en ous throm bosis an d resu l-

tan t cerebral v eno us in farctio n in

pregnant and im m ed iate ly p ostpartum

f em ales. Freq uently , the in itial m ani-

f estation is headache . S e iz ures , e ither

f ocal or g en eraliz ed , are com m on.

A cu te hem ip aresis is the m o st co m -

m o n f ocal f eature on n eu ro log ic

ex am in ation . Papilledem a can app ear

as in tracranial pressure rises d ue to

resu ltan t o bstruc tion o f cereb ral

v eno us outf low . T h e ap pearance o f

these sig ns or sy m p tom s in a g rav id

or p ostp artum ado lescen t sho uld raise

su sp ic ion abo ut the ex is ten ce o f

un derly ing cereb ral v en ous throm b o-

sis. I f se iz ures o ccur, an ticon v ulsan t

treatm ent sh ould b e in itiated . O nce

th e d iagno sis is con f irm ed , an tico ag -

u lan ts sh ould b e adm in istered .

Fin ally , insec t s tings hav e cau sed f ocal

cerebral in farctio n in ch ildren . W asp

and scorp ion v eno m activ ate p latele ts,

p ro m otin g th ro m bo genesis, w hich can

culm inate in fo cal in farctio n .

M etabo lic E tio lo gies

H om o cy stinu ria, a d isorder o f hom o-

cy ste ine m etabo lism , can cau se

throm botic strok e in ch ild ren

(T able 3 ). A bnorm al h om ocy ste ine

m etabolism resu lts f rom on e o f three

heritab le enz y m atic de f ec ts. T h e m ost

strik ing p henoty pe resu lts f ro m de f i-

c iency o f cy stath ion in e sy n the tase ,

the en z y m e th at cataly z es the catabo-

lism of hom ocy ste ine to cy stath ion-

m e . A ccum u latio n o f bo th ho m ocy s -

te ine and m eth ion in e resu lts .

C hild ren af f ec ted by th is au to som al

recessiv e d isorder m anif est m ar-

f an oid hab itus, g lob al d ev elo pm en tal

de lay , lens d islo cation , and th rom bo-

em bo lism . S erum hy p erho m ocy s -

tein em ia in ju res the v ascu lar endo the-

hum , w ith the d en uded v esse l w all

becom ing a site fo r throm bosis . T h e

resu ltin g thro m bu s m ay rem ain at its

site o f orig in or it m ay em bo liz e to a

dis tal locus. T heref ore , strok e m ay

hav e throm b otic or em b olic charac-

teristic s, and b oth arterial and v enou s

in f arc ts m ay resu lt. T reatm ent is

d ie tary an d aim ed at redu c ing lev e ls

o f ho m ocy s tein e in serum . Py rid ox in e

ad m in is tration and m eth ion in e

restrictio n are ef f ec tiv e as prop hy lac -

tic therap y f or th e de leterious seq ue-

lae in 3 0 to 40 of treated p atien ts

w h o h arbo r a d ef ect o f cy stath ion ine

syn thase .

S u lf ite o x idase de f ic iency , anoth er

au toso m al recess iv e d isord er o f su lfu r

am ino ac id m etab olism , resu lts in the

accum ulation o f serum sulf ite s. T he

assoc iated pheno ty pe m ay be du e to

de f iciency o f e ither th e enz y m e or its

assoc iated and essen tial p terin -co n-

tam ing m oly bdenu m co fac tor. M ental

re tard atio n , se iz ures, len s d isp lace -

m ent, and acute hem ip leg ia resu lt.

T he m ech anism of the strok e -lik e

ep iso des has not b een e luc id ated

fu lly . I t is po ssib le that isch em ic

m ech anism s are no t inv o lv ed an d that

d irec t m etab olic neuro to x ic ity

accou nts for th e sud den onse t o f

de f ic its resem bling those o f strok e.

S u lf ite s an d 5-su lf ocy ste in e accum u-

late in urine . D ie tary attem pts to

reduce su lf ite accum u latio n hav e

b ee n u nsu cc essf ul.

Fabry d isease, a lip id sto rage dis -

ease , is attribu tab le to ceram ide tri-

hex os idase de f ic iency . It resu lts in

accum u lation o f th e sph in golip id , tn -

hex os ide , in the k id ney , v ascu lar

en doth eliu m , and cornea. S y m ptom s

beco m e app aren t in ch ildh ood or ado-

lescence . A n giok eratom as and p ain fu l

paresthesias o f ten are the f irst sy m p -

tom s, f o llo w ed by renal f ailu re .

H ow ev er, the end othe lial accum ula-

tion o f sph ingo lip id in v esse l w alls

m ay cause cen eb nov ascu lar occ lusion

an d sub seq uent strok e. R ecurren t

stro k e is no t uncom m on in th is rare

X -link ed d isorder. S up portiv e care

an d treatm ent desig ned to im pro v e

renal f un ctio n and m in im iz e pain are

impor tan t .

M itochon drial d isorders m ay b e

m anif ested by recu rren t and som e-

tim es catastrop hic s trok e. T h e sy n -

drom e of M EL A S (m ito ch on drial

encephalom yop ath y , lac tic acid osis,

an d strok e ) presen ts in ch ildh oo d and

is due to a m utatio n o f m itochon drial

D N A . T h e m o st com m on b iochem ical

f ind ing is a de f ic iency o f co m plex I

o f the elec tro n tran spo rt chain . A n

e lev ated lev e l o f lactate in th e serum ,

or m o re co nsisten tly , in the C S F, sup -

T A BL E 3. C om m on

G enetic C auses of Str ok e

T hr om botic/E m bolic Str ok e

O rganic ac idem ia

M ito ch ond rial d isorders

Adapted from N atowicz M K el l ey

RT .

M en del i an eti ologies of str ok e

A nn N euro l.

22:1 98 7; 1 73


http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/


10/16

F IG U RE 3. Axial cranial CTdemonstrat-

ing a hypodense region in the middle

cerebral artery territory of the left hemi-

sphere ar rowheads). This study was

obtained from a 4-month-old infant who

has tetralogy of F allot and presented with

focal seizur es.

Pediatr ics in Review Vol. 17 No. 8 August 1996

273

:NEUROLOGY

:

Stroke s

ports the d iagn osis . T h e d iagn osis can

b e con firm ed from m olecu la r b lood

ana lysis . A lth ough som e featu re s o f

M ELA S are sha red by o th er m ito -

chondrial syn drom es, hem ip are sis o f

ab rup t on se t, pa r ticu lar ly w ith hem i-

anop ia, is ch aracte r is tic o f th is sy n -

d rom e . A m ate rna l fam ily h isto ry o f

m ig ra ine is comm on . Exc ruc iatin g

headache th at resem ble s m ig ra ine

usua lly p recedes o r accom pan ie s th e

stro ke -lik e ep isod es . S e izu re s, sen -

so rin eu ra l h earing lo ss , dem en tia , an d

short s ta tu re u sua lly a re p resen t a t

som e po in t in the co urse o f illn es s .

B ecause the s trok es invo lve the po s-

ten o r ce reb rum , h em ian op ia o r m o re

com plex v isua l de fec ts a re cha rac te r-

is tic . N eu rop ath o log ic study of b ra in

from pa tien ts w ho have M ELA S has

sh ow n cystic cav itie s an d nec ro sis o f

th e co rtex , e spec ially the p oste rio r

ce reb rum , w ith rela tive spa rin g o f

w hite m atter .

O th er m etabo lic d iso rd e rs h av e

b een assoc ia ted w ith stro ke in ch ild -

ho od . U rea cyc le de fec ts , especia lly

o rn ith ine tran scarbam y lase de ficiency

tha t p re sen ts in hem izygous g ir ls , c an

cause stro ke . M etab o lic d iso rd ers

su ch as these ref lect som e of th e he ri-

tab le d iso rde rs th at a re as soc ia ted

w ith stroke (T ab le 3 ) .

EMBOLU S

Cong en ital h ea rt d isea se rem a in s a

ve ry com m on cau se o f stro ke in

ch ild hood . B o th the struc tu ral ca rd iac

de fec ts an d the com plica tio ns rela ted

to co rrec tive su rge ry co n tr ibu te sig -

n if ican tly to th e occurrence o f strok e.

C h ild ren w ho have cy an o tic con gen i-

ta l heart d isease face th e g rea te st r isk .

T he m o st comm on ce reb ro vascu la r

even t is em bo lic stro ke . C a rd iac

de fec ts in vo lv ing righ t-to - le ft sh un ts

a llow em boli o r ig ina ting in th e

pe riphe ral c ircu latio n to b yp ass the

standa rd filtra tion and rem ova l b y the

pu lm on ary v ascu lar b ed . T hu s,

em bo li en te rin g th e heart v ia venou s

retu rn m ay b e shun ted to th e pe rip h -

e ra l ar te ria l c ircu la tion , on ly to lo dge

in the ce reb rov ascu lar tree (F ig . 3 ) .

P a ten t fo ram en ova le (PFO ) co n-

tr ibu te s s ign if ican tly to th e occur-

ren ce o f stroke in ch ild ren and young

adu lts . E ch ocard io g rap h ic eva lua tion

of yo ung pa tien ts w ho h av e su ffered

stro ke reveal PFO or ev id en ce of

r igh t- to - lef t shu n ting in m o re th an

th ree tim es as m any p atien ts su ffe r ing

stro ke than con tro l pa tien ts . T rans -

eso phag ea l echo ca rd iog raph y con -

duc ted w ith V alsalv a bu bb le stu d ie s

fo r ev idence of d irec t r igh t- to - lef t

co ndu ctio n is the m o st u se fu l d iag -

n ostic te st.

C ongen ita l va lvu lar d efects such as

ao rtic steno sis an d m itra l s ten osis can

re su lt in stro ke . R h eum a tic va lvu lar

d isea se , on ce a comm on cau se o f

em bo lic stro ke , has b ecom e in fre -

quen t, b u t in fected v a lves foun d in

su bacu te bac te ria l en doca rd itis (SBE )

still po se con side rab le risk . In fectiv e

m itra l and aortic v alv u la r v eg eta tion s

m ay d islo dge , trave l d is tally , an d u lti-

m ate ly occ lude ce reb ra l a rte r ies . T he

m ost comm on organ ism s fou nd a re

strep tococc i an d staphy lococc i.

V eg e tatio n still m ay em bolize an d

cause stro ke , ev en a fte r h av ing b een

ste riliz ed . F ina lly , em bo li from

in fected va lvu la r vege tatio ns m ay

lead to o th er vascu la r le sion s. F o r

exam p le, em bo li m ay trav e l to the

ce reb ra l vascu la tu re and seed th e

adven titia o f the ce reb ra l v es sel. T h e

resu ltan t in fectio n an d in flam m ation

w eak en s th e vesse l, caus ing dev elo p -

m en t o f a m yco tic an eu rysm . Th ese

aneurysm s typ ically o ccu r in th e d is-

ta l ce reb ra l vascu la tu re . They m ay lie

do rm an t fo r som e tim e be fo re th eir

rup tu re leads to SAH or IPH and

resu ltan t neu ro lo g ic sig ns (F ig . 4 ).

R ecen tly , foca l ce reb ra l in ju ry

re la ted to co rrec tive su rge ry fo r con -

gen ita l ca rd iac de fec ts h as been id en -

tified , su ch as ce reb ra l v ascu lar acc i-

den ts d u ring the Fon tan correc tion . A

pa rado x ic d is soc iatio n o f in travascu -

la r and m itocho ndrial oxy gena tion

occu rs du rin g in traop era tive deep

hypo the rm ic card io pu lm ona ry byp ass

and circu la to ry a rre st, w h ich m ay

p rov ide a clu e to th e cau se o f such

ce reb ra l in ju ry . P oor ce llu la r ox y-

g en atio n , pa rticu lar ly at th e m ito -

ch ond ria l leve l, can be assoc ia ted

w ith ce reb ra l in ju ry .

F a t o r a ir em bo li can ram ify in the

ce reb ra l v esse ls . T h ese em bo li m ost

com m on ly a re fo rm ed fo llow ing trau -

m a in vo lv ing lon g bon e fractu re s .

H ow ev e r, b o th o f these ty pes o f

em bo li hav e been assoc ia ted w ith

no n traum a tic con d ition s. F a t em bo li

have been obse rved in assoc ia tion

w ith panc rea titis , s ick le ce ll d isea se ,

conn ec tiv e tissue d iseases, an d in tra-

veno us lip id adm in istra tion . B o th fa t

and a ir em bo li h av e been observed

afte r ca rd io pu lm on ary bypass

su rge ry . B ecause fa t o r a ir em bo li

occu r a s show ers, m u ltip le s ites w ith -

in the CN S m ay be invo lved . A s a

resu lt, im pa ired con scio usn es s, som e-

tim es accom pan ied b y de lir ium , m ay

be ob se rved . F o ca l o r late raliz ing

neuro log ic signs a re ap pa ren t in on ly

one th ird o f pa tien ts .

H EMORRHAGE

A lth ough som e coagu la tion d istu r-

bances m ay pred ispo se a pa tien t to

ischem ic stro ke , o th ers m ay prom o te

in trac ran ial b leed ing . B o th A and B

hem oph ilia s a re X -lin ked d iso rde rs

tha t m ay resu lt in in trac ran ial b leed -

ing (T ab le 3 ). B leed in g m ay occur in

eith e r in trapa ren ch ym a l o r sub arach -

no id lo catio ns. H em oph ilia A arise s

from fac to r V III de ficiency . A ffec ted

m ale s m ay expe rience in tracran ia l

b leed ing in as soc iatio n w ith head

traum a. U nfo rtu na tely , sp on taneou s

in trac ran ial b leed ing u nassoc ia ted

w ith h ead traum a a lso occurs . T he

risk o f sp on tan eo us b leed ing rise s as

the seve rity o f fac to r V III d efic ien cy

in creases . H em oph ilia B de rives from

a de fic iency of fac to r IX . In trac ran ia l

b leed ing is le ss freq uen t in these

pa tien ts than in th ose w ho have

h em oph ilia A . T he le ss frequen t

occu rrence o f hem oph ilia B com -

pa red w ith hem oph ilia A m ay acco un t




11/16

F I GU RE 4. M ycotic cerebral aneurysm hemorrhage. A. Cranial CT reveals hvperdense region in left tempor al lobe arr owheads), repre-

seining intraparenchyinal hetnorrimage. B. Cerebral

angiography

in lateral view shows lobulated

vascular abnormality in the timiddle

cerebral artery tree ar rows). C’ . Anterior-posterior angiographic view confirms the location oft/ ic vascular abnor,nalitv in the middle

cerebral

artery

straight arrow), which is located lateral to the more medially located anterior cerebral artery curved arrow). These

neuroradiologic studies were performed on a boy who presented with acute onset of aphasia and rig/it hemipare.sis 2 weeks after the dis-

coven’ of low-grade fever and a cardiac m u rm u r

274

Pediatrics iii Review Vol. /7 No. 8 August 1996

N U R O L O Y

t r o k s

for the le ss frequent observation of

intracranial bleeding . Clinical symp-

tom s depend on the intracranial loca-

tion of the hemorrhag e. If the bleed-

ing occurs in the subarachno id space ,

severe headache , nuchal rig idity , and

mening ismus occur. M ental status

frequently is altered. If bleeding

occurs w ithin brain parenchyma,

focal c linical features, inc luding

hemiparesis , may be observ ed.

Sev ere thrombocytopenia leads to

cerebral hemorrhage in v ery few

patients . S ignificant risk of IPH

appears to occur only at platele t

counts o f 20 ,00 0 /mm3 or le ss . Small

pe techial hemorrhages into w hite

matter are more common than larg e

parenchymal hemorrhag es . Causes o f

thrombocytopenia include idiopathic

thrombocytopenic purpura, infec tion,

and malignancy . The features o f these

underly ing causes dom inate the c lini-

c al pi cture .

SAH occurs among children w ho

have s ickle ce ll disease , although the

frequency is les s than that o f infarc-

tion, occurring in few er than 2% of

patients . The ruptured cerebral

aneurysm that frequently is found in

adult sickle ce ll patients w ho hav e

SAH is absent in children. Clinical

f indings inc lude sev ere headache ,

vom iting , and altered mental s tate .

M eningeal signs and focal neuro lo g ic

de ficits m ay be found on examina-

tion. A ng io graphy usually should be

perfo rmed to detec t any surg ically

co rrectable vascular les ion underly -

ing the hemorrhage . Medical therapy

consisting of transfusio n therapy has

be en s ug ge ste d.

A rterio venous malfo rm ation

(A VM ) o f the brain is the mos t com -

mon cause o f intracranial hemorrhage

in preado lescent children and is more

common in males than females. This

deve lopmental anomaly presents w ith

hemorrhage more frequently in chil-

dren than in adults . The AVM con-

s ists o f dilated vascular channe ls ,

som e o f w hich exhibit the highly

muscularized w alls o f arterio le s .

Glio tic neural tissue resides in and

among the vascular branches o f the

malformation. The most frequently

observed ev ents assoc iated w ith AVM

in children are se izures and hemor-

rhag e. The vast majority o f A VMs are

lo cated in the cerebral hem ispheres ,

w ith 1 0% arising in the po sterior

fo ssa. The c linical feature of hemor-

rhag e due to A VM may be acute onse t

o f fo cal neuro log ic de ficit, according

to the area o f brain in w hich the hem-

orrhag e has o ccurred. Children who

have AVM complicated by hemor-

rhag e hav e a higher mortality rate

than adults . The risk o f hemorrhag e

from an unruptured AVM approx i-

m ates 3% per y ear.

Intracranial aneury sms are a com-

mon cause o f intracranial bleeding in

patients y ounger than 20 years o f ag e.

S accular aneurysm s are more fre -

quent among males than females.

U nlike aneurysm s in adults , the mo st

common s ite o f bleeding in children

is along the intracranial portion of the

internal carotid artery ; the vertebral

and basilar arteries are o ther common

sites . Intracranial aneury sms in chil-

dren tend to be larg er than tho se

found in adults . M ost aneury sms are

due to v ascular dev e lopmental anom-

alie s , but there are other causes.

D iso rders o f connectiv e tissue , such

as Ehler-D anlo s syndrome and

Marfan syndrom e, are as soc iated w ith

the formation of saccular cerebral

aneury sms. Intracranial aneurysms

are more common among patients

suffering from po lycystic renal dis-

ease and those w ho have ao rtic co arc -

tatio n. Patients should be observed

c lose ly for complicatio ns asso ciated

w ith subarachno id bleeding from

aneury sm rupture . Hydrocephalus

causing increased intracranial pres-

sure may o ccur subsequently .

A neury smal bleeding that results in

signif icant SAH can precipitate cere -

bral v asospasm , w hich in turn can

cause secondary cerebral infarc tion.

V asospasm occurs mos t commonly 7

to 1 0 day s after the hemorrhage .

D IAGNOSIS

Once stroke is suspec ted, diagnostic

effo rts concentrate on do cumenting

the o ccurrence and discovering the

underly ing cause . N euro radio log ic

and laborato ry evaluation are con-

duc ted simultaneously . A suggested

fo rmat fo r diagnostic ev aluatio n is




12/16

R adiologic Evaluation

I . M RI

2. CCT

4’

L aboratory E val uation

4

I I

C N S I nf arcti on

r

Cardiac murmur found

o r P F O suspected

1 . CBC d i f f e r e n t i a l

2. Platelet count

3 . PT fPT

4 . E l e c t r o l y t e s

5.

To x i c ol o g y s c r e e n

6 . CS F e xa mi n a t i o n :

t o t a l p r o t e i n g l u c os e

c e l l c o u n t cu l t u r e s

l a c t a t e p y r u v a t e

7. Blood cultures

Subarachnoid o r

intraparenchymal

b l o o d f o u n d

Ad d i t i o n a l

def inition of

cerebral vasculature

n e e d e d

I

4

Echocardiography

Li

I M R A

2 . Percu taneous

a n g oi g r a m

I . A NA /RF

2.

Co a gu l a t i on p a ne l

including protein S. C ,

antithrombin I I I

assays

3. Antiphospholipid anti-

body

l u p u s a n t i -

coagulant assays

4. Serum amino acids

5. Lysosomal storage

e n z y m e s

Ped ia tric s in R eview Vol . /7 N o . 8 Au gu st 199 6

27 5

NEUROLOGY

-

‘S troke s

F IGU RE 5. D iag nos tic eva lua tio n o f stroke in ch ild ren : M R I = magne tic reson ance im ag itig ;

= cran ia l com pu ted tom og rap hy;

CB C

=

com ple te b lo od coun t; PT

= pro throm b in tim e: P iT = par tia l th rom bop las tin tim e: C SF =

cerebrosp ina l flu id ; A NA

=

an t i nu -

c lear an tib ody ; RF

=

rhe umato i d

fac to r ;

MRI4

= m agtze tic reso nance a ng iograph i

provided in Figure 5. CCI and M RI

provide rapid, topographic evidence

of infarction or intracranial hemor-

rhage. CCT images are acquired more

rapidly than M RI and provide clear

evidence of acute intracranial hemor-

rhage. M RI , which provides greater

resolution and structural detail than

does CCI , demonstrates smaller

infarctions. The emerging capability

of diffusion-weighted M RI permits

visualization of CNS infarction very

early in its course. This technique

focuses on the molecular motion of

water rather than on 11W , 12W , or

contrast-enhanced images. An

increase in intracellular water associ-

ated with a reduction in intracellular

transport functions occurs soon after

hypoxic-ischemic cerebral injury has

occurred, and di ff usi on- wei ghted

M RI can visualize the differences in

water flux between normal and dam-

aged cerebral tissue before changes

can be detected by conventional M RI .

M agnetic resonance angiography

(M RA ) yields reliable information

about blood flow in and structure of

large cervical and intracranial ves-

sels; small intracranial vessels are

visualized poorly. Invasive angiogra-

phy remains the neuroradiologic pro-

cedure of choice when detailed

knowledge of the cerebral vasculature

is requi red .

Initial laboratory tests should

screen for hematologic conditions

that predispose a child to stroke. In

addition, laboratory evidence of

inflammatory processes should be

sought. Serum electrolytes will pro-

vide initial evidence of a metabolic

acidosis that may accompany a mito-

chondrial disorder or an organic acid

disturbance. A toxicology screen

should be performed if drug-induced

stroke is suspected. A lumbar punc-

ture should be performed for cere-

brospinal f luid examination if CNS

infection, inflammation, or neoplastic

involvement is suspected. T he lumbar

puncture should no t be performed if

the physical examination findings or

neuroimaging indicate the presence




13/16

NEURO L O G Y

ke s

M ultip le scle rosis

27 6

P ed ia tr ics in R e view Vol . 17 N o . 8 A ugu st 199 6

of a space-occupy ing abnorm ality

cau sing inc rea sed in trac ran ial p re s-

su re . P e rfo rm ing th is p roced ure in a

pa tien t w ho has such a u n ila te ra l

sup ra ten to r ia l o r cerebe llar le sion

cou ld p recip ita te tran sten to r ial o r

transm agna l he rn ia tion , re sp ec tive ly .

If a strok e h as been docum en ted

c lin ically an d rad io log ica lly , bu t th e

in itia l pane l o f lab o rato ry te sts has

y ie lded no rm a l re su lts , add itio na l te st-

ing is w arran ted (F ig . 5) . E vid en ce of

coagu lo pa thy , system ic in f lamm ation ,

and lu pus an ticoagu lan t sh ou ld b e

sou gh t. C SF lac tate and pyruva te 1 ev -

e ls sho u ld b e ob ta in ed , ev en if se rum

lev e ls a re norm a l, if a m itochondrial

d iso rd er is susp ec ted . If the clin ica l

da ta su ggest a lyso som al s to rag e d is-

ease o r su lfite o x idase d efic ien cy , th e

approp ria te u rine o r b loo d te sts sho u ld

be pe rfo rm ed . E ch ocard io g rap hy

sh ou ld be pe rfo rm ed if th e ch ild w ho

has susta ined a s trok e a lso h as a ca r-

d iac m urm ur. In deed , if the re is strong

c lin ical susp ic ion of a PFO , echo ca r-

d io g rap hy w ith bubb le con tra st sho u ld

be p erfo rm ed . C u rren tly , app rox im a te-

ly 30 of all ca se s o f stroke in ch il-

d ren app ea r to b e id iop ath ic.

T REATMENT

R eso lu tion of the d iso rde r u nde rly ing

a strok e in ch ild ren is the m o st effec -

tive long -te rm the rap y . C orrec ting

ca rd iac de fec ts th at con tribu te to

em bo lus fo rm atio n is c ruc ial.

T rea tm en t w ith an ticoagu lan ts m ay

be necessa ry fo r ch ild ren w ho have

chron ic va lvu lar abno rm a litie s o r in

tho se ex posed to righ t-to - le ft sh un ts

fo r long pe rio ds. T he e ff icacy of w ar-

farm as an an ticoagu lan t is w ell

e stab lished ; the d rug com m on ly is

em plo yed fo r th is pu rpo se in adu lts .

H ow eve r, it m u st be used jud icio usly

in ch ild ren becau se the re is a g rea te r

p rob ab ility o f traum a and d ru g-re la t-

e d b le ed in g.

P roph y lac tic th erapy rem a ins the

co rne rsto ne of th erapy fo r th rom bo tic

stro ke . Exchan ge tran sfusion

desig ned to d im in ish the frac tion of

b lo od com posed o f hem og lob in 5 -

con ta in in g red b lood ce lls (RBC s)

red uces the r isk o f recu rren t strokes

am ong ch ild ren w ho have sick le ce ll

anem ia . R ecen t c lin ica l tria ls have

show n th at hy dro xyu rea can inc rea se

the lev e l o f fe tal h em og lo b in -con ta in -

ing RBC s in th ose w ho h av e s ick le

ce ll d isea se . A lth ough th is use o f

h yd rox yurea rem ains in vestiga tion al,

it m ay redu ce the occurrence o f

s tro ke am ong tho se w ho have sick le

ce ll d isea se . S troke du e to coagu la -

tio n fac to rs , such as p ro te in 5 , p ro tein

C , o r an tith rom bin III, are trea ted

best w ith an ticoagu latio n . I t ha s no t

ye t been d ete rm ined w he the r w arfa rin

o r ste ro id the rapy is m o re effec tive

p roph y lactic the rapy fo r s trok e

am ong p atien ts w ho have sym ptom s

of the lu pus an ticoagu lan t (o r

an tipho sph o lip id an tibo dy); recen t

da ta favo r th e use o f w arfa rin .

C e reb ral in fa rc tion d ue to a ir o r fa t

em bo li is trea ted b est w ith system ic

stero ids.

In g ene ra l, th e re is no e ffec tive the r-

ap y fo r the m etab o lic d is ea se s tha t

m ay lead to recu rren t stro ke , an d they

have a p oor p ro gno sis . H ow eve r , the re

is pa llia tive treatm en t fo r h om ocy stin -

u ria th at in vo lv es th e red uc tion o f sys-

tem ic hom ocys tein e. S om e pa tien ts

re spo nd to 100 to 50 0 m g/d ay oral v it-

am in B 6 (py rido x ine ) the rapy . T hose

w ho do no t respon d sho u ld be p laced

on a low m eth io n ine d iet. S tric t m eta -

bo lic con tro l co rrela te s w ith redu ctio n

of stroke o ccu rren ce .

In itia lly , treatm en t o f vascu la r m a l-

fo rm a tio ns con sisted o f an ticon vu l-

san t th erapy fo r second ary seizu re s.

S u rge ry w as re se rved fo r th ose A VM s

tha t b led a t p re sen ta tion . M R I has

allow ed be tte r localiza tion of th ese

m alfo rm a tion s, and p e rcu taneou s

selec tive em bo liza tion o f pa rt o r o f

the en tire A VM has pe rm itted re sec-

tion in situ atio ns con side red prev i-

ous ly to be inop e rab le . A VM s in c riti-

ca l reg ion s o f th e CN S tha t a re no t

am en ab le to su rg ery h av e b een trea t-

ed w ith ste reo tac tic rad iosu rg ery w ith

p rom isin g resu lts . R ad ia tion dam age

to th e CN S has com plica ted the

recove ry of ap prox im ate ly 3 of

pa tien ts . M ed ica l trea tm en t o f rup -

tu red an eu rysm s fo cuses on m ain tain -

in g b lood pre ssu re th rou gh in trav as -

cu lar vo lum e exp an sion ; such trea t-

m en t can redu ce th e inc idence o f po st-

hem orrhag ic vaso spasm . E a rly en thu -

s iasm for treatm en t w ith ca lc ium

ch anne l b lo cke rs has b een dam pen ed

by fa ilu re s in p ro spec tive , ran dom -

ized clin ica l s tud ie s . Th e op tim a l

treatm en t o f m oyam oy a d isease has

n o t b een d ete rm ined . C a lc ium chan -

n d b lo ck ers have been repo rted to

in crease co llate ral vesse l d iam e te r,

im prove pe rfu sion , an d am e lio rate

n eu ro log ic sym ptom s. S eve ra l su rg i-

ca l p ro ced ure s designed to re-e stab -

lish e ffectiv e pe rfus io n of en dange red

brain have been pe rfo rm ed w ith

en co urag ing re su lts in sm a ll num bers

o f pa tien ts , b u t add itio na l stud y and

expe rien ce a re req u ired .

Cond ition s That M ay

M im ic S troke

Acute hem ip leg ia m ost frequen tly

ind ica tes stro ke , bu t a h isto ry and

physica l ex am ina tion con sisten t w ith

the occu rren ce o f s trok e a re cr itic al to

the d iag nosis . B ecause stro ke occurs

m ost o ften in ch ild ren as a co nse -

qu en ce o f an und erly in g process, c ir-

cum spect ev a lu a tion of the ch ild ’s

cond ition fo r such a pred isposin g

cond ition w ill inc rea se th e accu racy

of the d iagno sis .

N o t a ll in s tan ces o f acu te on set o f

hem ip leg ia o r o the r fo cal de fic its rep -

re sen t acu te ce reb rov ascu lar ev en ts

(T ab le 4 ). H em ipa re tic seizu re s th at

are cha rac te rized by acu te la te ra lized

w eakness an d pre se rved m en ta l s tate

m ay b e a fo rm of p artial ep ilepsy . In

ad d ition , se izu re s can be fo llow ed by

a postic ta l (T odd ) pa ra lysis tha t m ay

m im ic the m oto r d efic it o f stroke .

S eek in g a h isto ry o f p rev iou s seizu re s

is e ssen tia l. A po sticta l pa raly sis is

sho rt- lived and no t a sso cia ted w ith

neuro rad io log ic ch aracte r is tic s o f

recen t stroke . P re se rv atio n of con-

sc io usn es s, a fea tu re no t sh ared by

T A B L E 4 O ther

C ond i t i ons in

Chi ldhood

T hat M ay Mim i c Stroke

Pos ticta l T odd pa raly sis

H em ipa re tic s eizu re s

Subdura l/E p idu ra l h em orrh ag e

Hypog ly cem ia

An em ia

A lte rna ting h em ip leg ia o f

ch i ldhood




14/16

:

NEUROLOGY

‘

‘Strokes

P e d i a t r i c s in

R ev iew Vo l. 17 N o . 8 A ug ust 19 96

27 7

general i zed seizures, may help di f f er-

entiate betw een epi lepsy and cere-

brovascular events. The diagnosis of

seizure remains cl i ni cal , but EEG

may help to establ i sh i ts occurrence.

Subdural and epidural i ntracranial

hemorrhages may m im ic stroke.

B ecause they are located adjacent to

the relati vel y nondistensible skul l , i f

they are suf f i cientl y large, they w i l l

exert pressure on the brain, causing

motor or sensory def i ci ts that cone-

spond to the af f ected cerebral area.

N euroimaging perm i ts def ini ti v e

diagnosis. I f no parenchymal injury

accompanies the hemorrhage, prompt

neurosurgi cal evacuation i s ef fecti ve.

M etabol i c di sturbances, such as

hypoglycem ia, may cause f ocal

motor def i ci ts resembl ing stroke.

Sim i larl y , transient hem iparesi s unas-

sociated w i th radiologic changes typ-

i cal of stroke have been observed in

chi l dren w ho have juveni l e diabetes

mel l i tus. T heref ore, survey ing for

condi ti ons that include these meta-

bol i c di sturbances is important v ia

serum electrol y te and glucose levels.

Sim i larl y , severe anem ia causing

reduced oxygen del i very to the brain

may resul t i n evanescent focal motor

def i ci ts; thus, evaluation of an hemat-

ocri t i s essential for any patient sus-

pected of hav ing suf f ered stroke.

A l ternating hem iplegia of chi l d-

hood A H C may simulate stroke in

chi l dren. This di sorder usual l y occurs

sporadical l y , but fam i l i al cases have

been described. The f i rst symptoms

of A H C appear before the age of 18

months. Repeated episodes of lateral -

i zed hem iplegia are most common,

but bi l ateral hem iplegia may occur.

H em iplegic attacks may last f or a f ew

m inutes to a few days. Ex tra-

pyram idal symptoms, oculomotor

dysfunction, and dysautonom ic f ea-

tures also may be present. Symptoms

disappear during sleep. Final l y ,

developmental delay or mental retar-

dation i s present in v i r tual l y al l cases.

Flunar i zine, a calcium channel block-

er, has show n some prom ise in i ts

apparent abi l i ty to reduce the f re-

quency and duration of hem iplegic

attacks, but experience is l im i ted.

Further study of potential therapies i s

necessary.

o n c l u s i o n

Focal cerebral i nfarcti on occurs

among chi l dren of al l ages. Thus, i t i s

important to recognize the signs of

stroke in neonates as w el l as in older

chi l dren. T he causes of stroke may be

thromboti c, embol i c, or hemorrhagic.

M ost commonly , pediatr i c stroke is

caused by structural abnormal i ti es of

cerebral vasculature, i nf l amm atory

condi ti ons that involve cerebral yes-

sels, or congeni tal heart di sease.

D iagnosis sti l l rel i es heav i l y on cl i ni -

cal recogni ti on of the cardinal signs

of focal cerebral i njury . Topographic

determ ination of the injured cerebral

area has been enhanced appreciably

by the advent of neuroradiologic

methods such as M RI . N onetheless,

several di sorders may m im ic presen-

tati on of f ocal cerebral i nfarcti on;

di f ferentiati ng them f rom stroke

depends heav i l y on an accurate

history and physical exam ination.

S UGG ES TED RE D ING

General

B utler I i . Cerebrovascul ar disorders of chi ld-

hood.

J C h ild N eum l.

1993;8: 197-200

Caplan L R .

S tr ok e: A C li nic alA pp ro ac h.

B utterw orth-H einemann: Stoneham, M ass;

1993:22-53

K err L , A nderson D M , Thompson JA , et al .

I schemi c stroke i n the young: evaluati on and

age comparison of patients six months to

thi rty nine years. J C h ild N euro l. 1993;

8:266-270

L anska M i , L anska D J, H orw i tz SJ, A ram D M .

Presentation, cl in ical course, and outcome

of chi ldhood stroke.

P ed ia tr N eu ro l .

1 9 9 1 ; 7 :3 3 3 3 4 1

N agaraja D , V erma A , Taly A B , et al . Cerebro-

v ascular disease in chi l dren.

Acta N eu ro l

S c a n d

1 99 4; 90 :2 5 1 25 5

Ri ela A , Roach ES. Et iol ogy of stroke in chi l -

dren. J C h il d Ne u ro l . 1993;8:201-220

Ri vk i n M , V olpe J. H ypox ic- i schem ic brain

injury i n the new born. S e mi n Ne u r o l

1 99 3; 1 3: 30

Schoenberg B S, M el l inger i F S ch oe nb er g D O.

C er eb ro va sc ul ar d is ea se i n i nf an ts a nd chil-

dren: a study of incidence, cl in ical f eatures,

an d su rv iv al .

Neuro l og ’

1978;28:763-768

V olpe JJ.

N eu ro lo gy o f th e

Newbo r n .

3rd ed.

Phi l adelphia, Penn: W B Saunders Company;

1995:299-310

W izni tzer M , M asaryk T . Cerebrovascular

abnormal i ti es in pediatri c stroke: assessm ent

using parenchymal and angiographic mag-

neti c resonance im aging.

An n N euro l.

1991 ; 2 9: 5 85 - 58 9

Spec if ic Causes of Stroke A mong

Children

Adams R M cK ie V. Nichols F et al. The use

of transcrani al ul t rasonography to predict

stroke i n sick le cel l disease. N E ng i J M ed .

1992;326:605 610

A l halabi M , M oore P. Seri al angiography in iso-

lated angi i ti s of th

stroke in childhood

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