cns prestn for mbbs student 2016brt

7/26/2019 CNS Prestn for MBBS Student 2016BRT

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SBikash Raj Thapa, MD


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Imaging modalities Simple radiography

-cheap preliminary screening -accuracy speci!city is lo"

#S$%- Ine&pensi'e( porta)le( multiplanar-dynamic( no-radiation Choice in neonates*in+ants

Computeried tomography- basic choice hge stroke( head injury( screening

MRI tissue characteriation is )etter .ngiography- mainly +or inter'entional radiology Radionuclide scan- is superseded )y CT MRI /ositron emission tomography 0/1T2

- e&pensi'e a'aila)le in 'ery ad'ance centre- /1T tracer like car)on, nitrogen, o&ygen- Demonstrates di3erence in +ocal )rain meta)olism- Major use in oncology


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N1#R4S4N4$R./56

NIC# .ssist in diagnosis%

/78( IC5(hydrocephalousetc

Monitorcomplications and

inter'entions%'entriculoperitoneal shunts


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C1NTR.8 N1R74#S S6ST1M

C.8CI9IC.TI4N, 56DR4C1/5.8#S

B.SICS 49 T#M4RS, IN9.RCTS,

IN91CTI4NS 4N CT S/IN1

D*D% C488./S1 71RT1BR.1% TB

D*D% M1T.ST.TIC SC81R4TIC 81SI4NS

4ST14M618ITIS


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Hypodense lesions

:; In+arct

; 1dema

?; Meta)olicencephalopathy

@; 5ypertensi'eencephalopathy

A; 1ncephalitis

; 8ipoma

Hyperdense:; Intracranial calci!cations; Cysts% Colloid?; 1ndocrinal%

hypoparathyroidism@; Neurocutaneous syndromesA; .rterio'enous lesions


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Ring enhancing lesions

Metastasis

A)scess

Glio)lastoma In+arction

Contusion

Demylinating disease Radiation necrosis


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INTR.CR.NI.8C.8CI9IC.TI4NS

ormal intracranial calci!cationscan )ede!ned as all age-related physiologic andneurodegenerati'e calci!cations that areunaccompanied )y any e'idence o+ disease and

ha'e no demonstra)le pathological cause; /IN1.8 $8.ND% 60% adult; >14mm: neoplasm 5.B1N#8.% 30% C54R4ID /81#S% 10% B.S.8 $.N$8I.

D#R. /1TR4C8IN4ID 8I$.M1NTS SSS


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CR"#$C%R%&R"'

(R")*"


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Classi!cation o+ head injury

+rimary in,ury%

Those occurring as a direct result o+initial traumatic e'ent;

econdary in,ury:

These are conseEuences o+ primaryinjuries

9reEuently more de'astating than theprimary injury


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+rimary in,uries%

Skull F, scalp hematoma* lacerations 1&tracere)ral hemorrhage

1pidural hemorrhage

Su)dural hemorrhage Su)arachnoid hemorrhage

Intraa&ial lesions% Di3use a&onal injury Cortical contusions Deep cere)ral gray matter injury Brainstem injury Intra'entricular* choroid ple&us hemorrhage


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Secondary lesions%

Cere)ral herniations

Traumatic ischemia, in+arction

Di3use cere)ral edema 5emorrhages


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Imaging Strategy

Imaging o+ acute head trauma is per+ormedto detect treata)le lesions )e+ore secondaryneurologic damage occurs;

Currently, this is )est per+ormed )y CT +orse'eral reasons%

it is Euick "idely a'aila)le

5ighly accurate in the detection o+ acute intra-

a&ial and e&tra-a&ial hemorrhage, as "ell asskull, temporal )one, +acial, and or)ital +ractures;

Monitoring eEuipment is easily accommodated;


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Skull 9ractures%

Types% 8inear F

Depressed F( ping-pong*pond +racture0ne")orn2

Comminuted F

Compound F

$ro"ing F% 0leptomeningeal cyst2

Can in'ol'e% Cranial 'ault Base o+ the skull

Sutural diastases


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1pidural hematoma

:->G pt imaged +or cra'iocere)ral trauma 1tiology- F that lacerates MM. or dural 'enous sinus 8ocation%

Bet"een skull dura 0)icon'e& shape2

Temporoparietal region commonest site H?G unilateral Do not cross suture Secondary herniation common

#maging% Bicon'e& e&tra-a&ial collection May )e heterogeneous due to hyperdense )lood

and hypodense serum or due to acti'e )leeding Chronic- /eripheral enhancement representing

dura and mem)rane +ormation )et"eenhematoma adjacent )rain parenchyma;


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.&ial CT scan demonstrates a )icon'e&, high-attenuation,e&tra-a&ial collection causing mass e3ect on the right +rontallo)e and mild midline shi+t 0su)+alcial herniation2; Note ho"the epidural hematoma does not e&tend )eyond the right

coronal suture


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ubdural Hematoma

Most lethal o+ all head injuries Mortality rates upto ?-?G Stretching and tearing o+ )ridging cortical 'eins

as they cross sd space common

disruption o+ penetrating )ranches o+ super!cialcere)ral arteries less common

8ocation% Bet"een dura and arachnoid 9rontoparietal con'e&ities middle cranial +ossa

Jidespread than 1D5 Crescentic shaped, cross suture, e&tend into interhemispheric

!ssure DoesnKt cross midline ?G unilateral


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Su) .rachnoid hemorrhage

Traumatic; Spontaneous S.5%

Ruptured arterial aneurysm 0A-G2

.rterio'enous mal+ormation 0:G2 4ther rare causes%

Tumor )leeding Mycotic aneurysm Cortical throm)osis Dural .7 !stula .rterial Dissection

No cause identi!a)le in angiogram


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Noncontrast a&ial CT scans in t"o di3erent patientsdemonstrate high-attenuation material "ithin the sulci and

right syl'ian !ssure consistent "ith su)arachnoidhemorrhage;


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5ydrocephalus

Denotes an increase in the 'olume o+ CS9and thus o+ the cere)ral 'entricles;

Obstructive and non-obstructive 0on

the grounds o+ "hether or not there iso)struction o+ CS9 path"ays in the'entricles or in the su)arachnoid space2

Communicating and non-communicating 0addressing "herethe o)struction is located2;


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4)structi'e hydrocephalus

passage o+ CS9 "ithin the 'entricular system or in thesu)arachnoid space is impaired at some point communicating o)structi'e hydrocephalus

passage o+ CS9 +rom the 'entricular system and into thesu)arachnoid space is unimpeded )ut a)sorption o+ C9S 'iaarachnoid granulations is impaired

su)arachnoid haemorrhage ormeningitis e&tra-a&ial CS9 spaces 0e;g; Syl'ian !ssures and sulci2 are also

distended

non-communicating obstructive hydrocephalus o+ten merely re+erred to o+ as obstructie hydrocephalus due to o)struction o+ CS9 out Lo" at any point 0e;g; aEueduct

stenosis,colloid cyst o)structing the +oramen o+ Monro2 up-stream 'entricles are dilated and e&ert mass e3ect upon

adjacent )rain 0e;g; e3acement o+ sulci2


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Non-o)structi'e hydrocephalus

o+ten re+erred to as e-acuodilatation o0 the entricles

CS9 can pass out o+ the 'entricles andinto the )asal cisterns "ithoutimpediment, and is readily a)sor)ed

'entricles are enlarged due to loss o+adjacent )rain parenchyma


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Characteristics o+5ydrocephalus

7entricular enlargement disproportionate to thedegree o+ sulcal "idening

1nlargement o+ temporal horns

/eri'entricular Luid secondary totransependymal CS9 permeation

1nlarged =rd'entricle 0out"ard )o"ing o+ thelateral "all2 "ith large suprapineal andchiasmatic receses and in+erior )o"ing o+ the

LoorIn children < years the head circum+erence is

o+ten the )est distinguishing +eature )et"eenhydrocephalus and atrophy;


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M1.S#R1M1NTS

9rontal horns 0Monro2% > yrs : yrs:?

7entriculohemispheric ratio% ==G in adults >G in children

Third 'entricle

?mm% children Amm% @yrs Hmm%O@yrs


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Normal CT Brain5ydrocephalicBrain


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Colloid cyst


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STR4P1


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4n CT @G o+in+arcts are seen"ithin =-@ hrs and

'irtually all areseen in hours;

.D7% 5ge stroke0MRI con+using2

MRI- Di3usionrestriction 0DJI2"ith reduced .DC

has )een o)ser'edas early as =minutes a+ter theonset o+ ischemia;


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Imaging protocal Nonenhanced scanning must )e per+ormed as

soon as possi)le a+ter the stroke is suspected;

and the key role of nonenhanced CT is thedetection of hemorrhage or other possi)lemimics o+ stroke 0eg,neoplasm, arterio'enous

mal+ormation2;


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CT 9indings in In+arction

Hyperacute: 12 hrsQ Normal ?-@GQ 5yperdense artery 0dense MC. sign2Q 4)scuration o+ the lenticular nucleusQ loss o+ gray-"hite inter+aces 0insular ri))on sign

"cute: 12-24 hrsQ 8o" density )asal gangliaQ sulcal e3acement

1 to 3 ays:Q Increasing mass e3ectQ Jedge-shaped lo" density area in'ol'ing gray and "hite

matterQ /ossi)le hemorrhagic trans+ormation


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"ial unenhanced C(images in a proimalsegment o0 the le0t *C"

in a 3-year-old man a5and a distal segment o0the le0t *C" in a 62-year-old 7oman b58obtained 2 hours a0terthe onset o+ righthemiparesis and aphasia,sho" areas o+hyperattenuation 0arro"2suggesti'e o+ intra'ascular

throm)i


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"ial unenhanced C(image obtained in a ?=-year-old man sho"s

hypoattenuation ando)scuration o+ the le+tlenti+orm nucleus 0arro"s2,"hich, )ecause o+ acuteischemia in the

lenticulostriate distri)ution,appears a)normal incomparison "ith the rightlenti+orm nucleus


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"ial unenhanced C(image8 obtained in a A=-year-old "oman


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Drawings (top) illustrate the territories(blue) of the ACA, middle cerebral artery (MCA)

, and posterior cerebral artery. CT scans (bottom) show established infarctions of

these arteries


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C7.

Intracere)ral

hematoma)asal nucleiregion "ithmass e3ect


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IN91CTI4NS


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Congenital * neonatal in+ections

Meningitis

/yogenic parenchymalin+ections

1ncephalitisTu)ercular and +ungal in+ections

/arasitic in+ections


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C*9

DN. 'irus Most common cong C!" infection

0also cause cardiac anomalies, hepatosplenomegaly2

/redilection +or peri'entricular su)ependymal germinal matri& Jidespread peri'entricular tissue necrosis and su)seEuent

dystrophic calci!cation;

/lain !lm microephaly "ith egg shell- like peri'entricularcalci!cation

#S*CT*MRI encephaloclastic lesions, peri'entricular ca,su)ependymal para'enticular cyst, 'entriculomegaly

MRI- delayed myelination, encephalomalacia, migrational

disorder 0lissencephaly, polymicrogyria, pachygyria2

P i t i l l ifi ti i CMV i f ti


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Periventricular calcification in CMV infection

Fink K R et al Radiographics !"#"$%"''#'*

!"! by #adiolo$ical %ociety of &orth America


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($$+'"*$#

T; gondii, o)ligate intracellular parasite

Multi+ocal, scattered lesions 0)asal ganglia,corte&, peri'entricular location and "hitematter2

No migrational disorder

Triad 0imaging2

hydrocephalus 0due to ependymitis-leads toperiaEueductal necrosis-aEueductalstenosis2

)*l chorioretinitis

intracranial calci!cations


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.&ial unenhanced CT imagere'eals a peripherallycalci!ed lesion 0arro"2 in theright caudate head that is a

seEuela o+ pre'iousto&oplasmosis in+ection; Thelo"-attenuation mass lesion"ith surrounding edema inthe region o+ the le+t )asalganglia is +rom a ne" +ocuso+ to&oplasmosis;


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M1NIN$ITIS


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Role o0 C( in meningitis

to identi+y contraindicationso+ a lum)ar puncture to identi+y complications that reEuire prompt

neurosurgical inter'entions such as symptomatichydrocephalus, su)dural empyema, and cere)ral a)scess;

CT scans may re'eal the causeo+ meningeal in+ection; $torhinologic structures and congenital and posttraumatic

calarial de0ects can also )e e'aluated CT cisternography may depict CS9 leaks, "hich may )e the source

o+ in+ection in cases o+ recurrent meningitis


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onenhanced C( scan !ndings may )e normal 0O?G o+ patients2

e3acement o+ )asilar con'e&ity cisterns )y inLammatorye&udates

mild 'entricular dilatation and e3acement o+ sulci cere)ral edema and +ocal lo"-attenuating lesions;

Contrast-enhanced C( scans Meningeal ependymal enhancement 5elp in detecting complications o+ meningitis, such as

su)dural empyema 7enous throm)osis, in+arction

Cere)ritis*a)scess 7entriculitis;


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#nenhanced a&ial CT imagesho"s high-attenuationmaterial in the )asilar

cisterns


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Cerebritis and deelopingabscess 0ormation in apatient 7ith bacterialmeningitis . (his contrast-

enhanced8 aial computedtomography scan sho7s asmall8 ring-enhanced8hypoattenuating lesion inthe le0t basal ganglia anda le0t subdural


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"bscess in a patient 7ithbacterial meningitis. (hiscontrast-enhancedcomputed tomographyscan sho7s a ring-enhancing8hypoattenuating massabscess5 7ith peripheraledema and mass e=ect.


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&ilateral subduralempyema in a patient7ith bacterial meningitis.(his computedtomography scan

demonstrates theimportant diagnostic0eatures o0 meningitis:prominent enhancemento0 the margin andincreased attenuation o0the empyema.


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CNS tu)erculosis

5ematogenous dissemination usually +rom pulmonaryin+ection

*eningitis- most common mani+estation +arenchymal lesions

Caseating granuloma

#sually solitary, multiple in :*= Cortical, su)cortical, )asal ganglia lesions; Cere)ellum in

children (ubercular abscess

indistinguisha)le +rom caseating granuloma* pyogenica)scess

thinner smoother "all multiloculated larger0O=cm2 surrounding edema is less than that in pyogenic a)scess


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Multiple )ilateral ring-enhancing lesions0tu)erculomas2 in the +rontal and parietal lo)es


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/arasitic in+ections

NCC

1chinococcosis

.me)iasis /aragonimiasis

Spargonimiasis

Malaria


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Neurocysticercosis

8ar'al +orm o+ T; solium

Most common C!" #arasite

location

Brain parenchyma- corticomedullary junction

Intra'entricular in


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C( scan o0 the brain#n parenchymal CC8 the arious stages are as 0ollo7s: 9esicular stage is characteried )y a small, rounded, lo$-density area

in the )rain parenchyma, "ithout edema or enhancement "ith contrast;Sometimes the scole& can )e seen as a hyperdense dot inside the

hypodensity;

Colloidal esicular stage is characteried )y a hypodense or isodenselesion "ith edema and a ring-enhancing #attern a+ter administration o+contrast; This is the acute encephalitic +orm, mani+ested as a reaction )ythe host;

>ranular nodular stage-%C( sho"s isodense cyst "ith hy#erdensecalci%ed scole& ;

odular Calci!ed stage is characteried )y a dead cysticercus; InN1CT, a small calci%ed nodule $ithout mass e&ect or enhancementis typical; 5o"e'er, perilesional edema may occur around already

calci!ed cysts 0may )e upto ? yrs2 and is related to symptom relapse;

(ransitional stages bet7een these stages also can be seen; thepattern on C( scan is a combination o0 2 stages.


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NCC


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Brain tumors


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Classi!cation )y histology "5>lial tumors- .strocytomas

4ligodendroglioma

1pendymalChoroid ple&us tumors-C//*C/C

&5 euronal and mied neuronal/glial tumors-ganglioma

gangliocytoma central neurocytoma

C5 *eningeal and mesenchymal tumors-meningioma

hemangio)lastomahemangiopericytoma

5 +ineal cell tumors- pineo)lastoma pineocytoma

%5 %mbryonal tumors- neuro)lastoma retino)lastoma /N1TS

?5 Hematopoetic tumors- lymphoma leukaemia plasmacytoma

>5 +itutary tumors H5 Cyst and tumor li@e lesions

R i d J54 l i! ti


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Re'ised J54 classi!cation

Su)di'ides into > grades 0II72 )asedon speci!c histologic 0eatures o+tumor such as cellularity, nuclear

atypia, mitotic acti'ity,pleomorphism, 'ascular hyperplasia,and necrosis;


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BR.IN T#M4#RS


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Most common

CNS tumor in adult% Metastasis /rimary CNS neoplasm% $BM Non-glial% Meningioma Neonates% Teratoma

$erm cell tumor% $erminoma Site o+ Sch"onnoma% 7esti)ular di'ision o+ 7III N7 Sellar*parasella% /ituitary adenoma /osterior +ossa tumor in adult% Metastases Tumor to calci+y% 4ligodendroglioma

Spinal e&tradural tumor% Metastasis Benign spinal neoplasm% 7erte)ral hemangioma Intramedullary spinal tumors in adults % ependymoma Intramedullary spinal tumors in children% .strocytoma


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In diagnosis o+ )rain tumors +ollo"ingpoints are important-

age

anatomic location character o+ tumor

perilesional edema

CT density and MR signalcharacteristics

contrast enhancement

$8I4M.*N1#R4$8I.8


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$8I4M.*N1#R4$8I.8Tumours

$lial cells% ?-: 0trillion2 neurons

.mong /rimary )rain tumours %appro& U are glioma

.mong glioma% O V are astrocytoma


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$lio)lastoma multi+orme

Most common and malignant o+ all

primary intracranial tumours 0 ?Gastrocytomas2

Rapidly enlarging malignantastrocytic tumor characteried )ynecrosisand neovascularity

Common in older age O?yrs( Rare

)elo" =yrs 'ocation:

o Supratentorial "hite matter mostcommon

Q 9rontal, temporal, parietal lo)es

Q 4ccipital lo)es relati'ely sparedo Cere)ral hemispheresO )rainstem O

cere)ellum

o Brainstem, cere)ellum - common inchildren

Jorst prognosis

C(:*ar@edi t t l


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intratumoralheterogenicity 7ithcentral lo7 densityregion s/o necrosis or

cyst 0orm5 is present inAB o0 all >&* 5emorrhage peripheral

oedema 0Fingers oedema2 is common

1nhancement is strong

inhomogenous "ith thickirregular rimenhancement

*R:T: sho"s poorlydelineated mi&ed signalmass "ith necrosis or cyst

+ormation "ith markedinhomogenousenhancement

T< sho"s heterogenousmass "ith mi&ed signal,central hemorrhage necrosis

(hic@8 irregular-enhancing rindo0 neoplastic tissue surrounding

necrotic core

S d + $BM


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Spread o+ $BM% 7ia)le tumor e&tends +ar )eyondsignal a)normalitiesW

Common

.long compact "hite matter tracts- coronaradiata, corticospinal tracts, corpus callosum&utter


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+#%


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Tu)ercular spine


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Tu)ercular spine common in N1/.8

:-=G -osseous in'ol'ement

O?G a3ects spinal column

commonest +orm o+ skeletal TB;

Dorsal spine - most commonly

in'ol'ed Most Common !rst = decades;

R.DI484$6


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R.DI484$6/lain radiography

signs % Reduced disc space Blurred paradiscal

margins Destruction o+ )odies 8oss o+ tra)ecular

pattern Increased

/re'erte)ral so+ttissue shado"

Su)lu&ation*dislocation

Decreased 8ordosis*kyphosis

Roentgen triad: primary 'ertebral lesion


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Roentgen triad: primary 'ertebral lesion,disc space narrowin$ and para'ertebral

abscess

(uberculouspondylitis

+yogenicpondylitis


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p y p y

4nset Insidious' chronic Acute

/rogress Slo" Rapid

Site Thoraco-lum)ar 8o"er lum)ar

ray changes At #resentation (-) $ks aft#resentation

&one sclerosis 8ack sclerosis *resent

+eriosteal reaction 8ittle or a)sent *resent

Multi+ocalin'ol'ement

Multiple contiguous'erte)rae

T"o or one

isc inolement 8ate 1arly

+osterior elementin

More +reEuent 8ess

Su)ligamentousspread

common *-

/araspinal mass +arge Small

Calci!cation ,allmark Rare

Spinal de+ormity Common 0kyphosis2 Not so


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7erte)ral Metastasis


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$eneral In+ormation

Metastatic disease is the most commontumor a3ecting the spinal column;

.ppro&imately AG o+ all spinal tumors

are metastatic in nature; /rimary carcinoma o+ the prostate,

)reast, lung, thyroid gland or intestinal

tract;

T"o types o+ spinal


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o ypes o sp ametastases

:; 4steoclastic * 4steolytic 0destruction o+ )one2 9reEuently associated "ith 'erte)ral )ody collapse; May )e mistaken +or plasma cell myeloma;


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7erte)ral Metastases o+ C?

ifferential dia$nosis for i'ory

'ertebral body

* Metastases

* +ymphoma* a$et disease

* +ess common -nfection (low $rade

i.e. T) or -diopathic se$mental

sclerosis

i l di h


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Con'entional Radiographs Con'entional radiography is relati'ely insensiti'e to )one

metastases;

?G destruction o+ the )one mineral content is necessary+or detection, thus it is not apparent on con'entionalradiographs the early stages o+ disease;

.s a rule, lesions need to )e X < cm to )e detected;

Con'entional radiography is still the pre+erred imagingmethod to determine )eha'ior 0i;e;2 sclerotic, osteolytic ormi&ed;

4steolytic metastases can mimic%o 4., Su)chondral cysts or Schmorl nodes o+ the spine

Sclerotic metastases may mimic other sclerotic )one lesionssuch as%o Tu)erous sclerosis, Mastocytosis or 4steopoikilosis


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Sclerotic metastases o+ 8< Common signs o+ spinal

metastases +ound oncon'entional radiographsinclude%

Destruction o+ thepedicle

.ssociated so+t-tissue

mass

MRI


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MRI

Imaging method of choice +or e'aluatingsuspected metastatic spinal pathology;

.pparent di3usion coeYcient 0ADC2'alues calculated +rom di3usion-"eighted

MR images is a relia)le +actor todistinguish vertebral metastasesfrom normal vertebrae;

MRI can also help detect metastaticlesions beforechanges in )onemeta)olism make the lesions detecta)leon )one scintiscans

Criteria #n0ection (umour


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o pattern o0ertebral inole

"t least 2 arounda=ected disc

Isolated* non contiguous

+ortion o0ertebral inole *ostlyendplates( postelements relati'elyspared

Body, typically pedicles

isc inolement Des Spared 0eception% +rostateca2

*arro7 signal T: lo", T< high,normal di3usion

T: lo", T< high, restricteddi=usion

%pidural

component

$ranulation tissue(

etends seeralleels a)o'e )elo"

?ocal mass( limited to le'el

a3ected 0eception% lymphoma2


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cns prestn for mbbs student 2016brt

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