hydrocephalus
TRANSCRIPT
BAGIAN ILMU BEDAH REFERAT
FAKULTAS KEDOKTERAN
UNIVERSITAS MULAWARMAN
HYDROCEPHALUS
Disusun Oleh :
Sizigia Hascharini Utami
0708015015
Pembimbing :
dr. Arie Ibrahim, Sp. BS
Bagian Ilmu Bedah
Fakultas Kedokteran
Universitas Mulawarman
2012
CONTENTS
Title ................................................................................................................
Contents ....................................................................................................... 1
Chapter I : Introducing ............................................................................... 2
1.1. Background ........................................................................................ 2
1.2. Aim ...................................................................................................... 2
Chapter II : Literature Review ................................................................ 4
2.1. Definition ............................................................................................ 4
2.2. History ................................................................................................. 4
2.3. Epidemiology ...................................................................................... 6
2.4. CSF Pathway .................................................................................... 6
2.5. Etiology ............................................................................................... 7
2.6. Pathophysiology ................................................................................. 10
2.7. Clinical Manifestation ..................................................................... 11
2.8. Diagnosis .......................................................................................... 13
2.9. Radiology ....................................................................................... 15
2.10. Differential Diagnosis ...................................................................... 17
2.11. Treatment .......................................................................................... 17
2.12. Prevention ...................................................................................... 25
2.13. Prognosis ........................................................................................... 26
Chapter III : Closing .................................................................................. 27
References ................................................................................................... 28
1
CHAPTER I
INTRODUCTION
1.1. Background
Hydrocephalus is a condition where in excess of cerebrospinal fluid (CSF)
accumulates within the ventricular system and cisterns of the brain leading
to increased intracranial pressure (ICP) and related consequences.
Hydrocephalus had multifactorial which can affect a fetus, infant, child or
adult. It can describe as imbalance between production and absorption of
CSF. Over production of CSF can caused hydrocephalus due to choroid
plexus tumors, but it is rare. (Ahmed, 2009)
Hydrocephalus is one of the most common clinical conditions affecting the
central nervous system with an incidence of three to for per 1000 births for
congenital hydrocephalus. (Ahmed, 2009)
Congenital hydrocephalus affects about one in every 1000 births. The
overall prevalence in the United States is about 0.5%. Most cases are
detected early, either at or soon after birth. The incidence of acquired
hydrocephalus in adults is not known because it occurs as a result of injury,
illness, or environmental factors. (Stanley, 2001)
In the United states incidence of congenital hydrocephalus is 3 per 1,000
live births; the incidence of acquired hydrocephalus is not known exactly
due to the variety of disorders that may cause it. (Alberto, 2000)
Incidence of acquired hydrocephalus is unknown. About 100,000 shunts are
implanted each year in the developed countries, but little information is
available for other countries. (Alberto, 2000)
On the other literature the prevalence of hydrocephalus was 0.82 per 1000
live births, 0.49 for children with infantile hydrocephalus and 0.33 for
children with myelomeningocoele. The prevalence of infantile
hydrocephalus decreased during the period from 0.55 to 0.43 per 1000. In
2
this group, the aetiology was prenatal in 55% and peri-postnatal in 44% of
the children. The origin was perinatal haemorrhage in all cases born very
preterm. (Persson, 2005)
The incidence of hydrocephalus is a bimodal curve with a peak curve in the
age range of children with various congenital malformations and the rest
associated with normotensive type of adult. Hydrocephalus in adults
reported approximately 40% of all cases. (Satyanegara, 2010)
1.2. Aim
Improve knowledges about definition, pathophysiology, diagnosis,
management, prognosis, and prevention of hydrocephalus.
3
CHAPTER II
LITERATURE REVIEW
2.1. Definition
Hydrocephalus is an abnormal enlargement of the ventricles due to
excessive accumulation of CSF from disturbance of its flow, absorption, or
uncommonly secretion. Normally the volume of CSF is 140 ml. (Kaye,
2005)
Hydrocephalus can be defined broadly as a disturbance of formation, flow,
or absorption of cerebrospinal fluid (CSF) that leads to an increase in
volume occupied by this fluid in the CNS. This condition also could be
termed a hydrodynamic disorder of CSF. (Rekate, 2009)
2.2. History
Hydrocephalus cases were regularly described by Hippocrates, Galen, and
early and medieval Arabian physicians, who believed that this disease was
caused by an extracerebral accumulation of water. Operative procedures
used in ancient times are neither proven by skull findings today nor clearly
reported in the literature. Evacuation of superficial intracranial fluid in
hydrocephalic children was first described in detail in the tenth century by
4
Abulkassim Al Zahrawi. In 1744, LeCat published findings on a
ventricular puncture. Effective therapy required aseptic surgery as well as
pathophysiological knowledge--both unavailable before the late nineteenth
century. In 1881, a few years after the landmark study of Key and Retzius,
Wernicke inaugurated sterile ventricular puncture and external CSF
drainage. These were followed in 1891 by serial lumbar punctures
(Quincke) and, in 1893, by the first permanent ventriculo-subarachnoid-
subgaleal shunt (Mikulicz), which was simultaneously a ventriculostomy
and a drainage into an extrathecal low pressure compartment. Between
1898 and 1925, lumboperitoneal, and ventriculoperitoneal, -venous, -
pleural, and -ureteral shunts were invented, but these had a high failure
rate due to insufficient implant materials in most cases. Ventriculostomy
without implants (Anton 1908), with implants, and plexus coagulation
initially had a very high operative mortality and were seldom successful in
the long term, but gradually improved over the next decades. In 1949,
Nulsen and Spitz implanted a shunt successfully into the caval vein with a
ball valve. Between 1955 and 1960, four independent groups invented
distal slit, proximal slit, and diaphragm valves almost simultaneously.
Around 1960, the combined invention of artificial valves and silicone led
to a worldwide therapeutic breakthrough. After the first generation of
simple differential pressure valves, which are unable to drain
physiologically in all body positions, a second generation of adjustable,
autoregulating, antisiphon, and gravitational valves was developed, but
their use is limited due to economical restrictions and still unsolved
technical problems. At the moment, at least 127 different designs are
available, with historical models and prototypes bringing the number to
190 valves, but most of these are only clones. In the 1990s, there has been
a renaissance of endoscopic ventriculostomy, which is widely accepted as
the method of first choice in adult patients with aquired or late-onset,
occlusive hydrocephalus; in other cases the preference remains
controversial. Both new methods, the second generation of valves as well
5
as ventriculostomy, show massive deficits in evaluation. There is only one
randomized study and no long-term evaluation. (Aschoff, 1999)
2.3. Epidemiology
Hydrocephalus is one of the most common clinical conditions affecting the
central nervous system with an incidence of three to for per 1000 births for
congenital hydrocephalus. (Ahmed, 2009)
Congenital hydrocephalus affects about one in every 1000 births. The
overall prevalence in the United States is about 0.5%. Most cases are
detected early, either at or soon after birth. The incidence of acquired
hydrocephalus in adults is not known because it occurs as a result of
injury, illness, or environmental factors. (Stanley, 2001)
In the United states incidence of congenital hydrocephalus is 3 per 1,000
live births; the incidence of acquired hydrocephalus is not known exactly
due to the variety of disorders that may cause it. Generally, incidence is
equal in males and females. The exception is Bickers-Adams syndrome, an
X-linked hydrocephalus transmitted by females and manifested in males.
NPH has a slight male preponderance. Hydorcephalus occur on in infancy
and is related to the various forms of congenital malformations and
adulthood, mostly resulting from NPH. (Alberto, 2000)
2.4. CSF Pathway
CSF produced by the choroid plexus in the ventricles 0,4 ml per minute or
about 500 ml in 24 hours. Then CSF flows from lateral ventricles through
foramen of Monro into 3rd ventricle. Then, CSF flows to 4th ventricle
through the aquaduct of Sylvius and through foramina of Magendie and
Luschka into subarachnoid space and basal cisterns. CSF circulates
through subarachnoid space and absorbed by the arachnoid villi of the
dural sinuses. (Kaye, 2005)
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2.5. Etiology
Classification of hydrocephalus (Kaye, 2005) :
Obstructive
o Lateral ventricle obstruction by tumours (basal ganglia glioma,
thalamic glioma)
o 3rd ventricle obstruction due to colloid cyst
o Occlusion aqueduct of sylvius
o 4th ventricular 0bstruction due fossa posterior (medulloblastoma,
ependymoma, and acoustic neuroma.
Communicating
o Obstruction through basal cisterns
o Failure the absorption of CSF through the arachnoid granulations
over the cerebral hemispheres.
o Infection (bacterial or tubeculosus)
o Subarachnoid haemorrhage (spontaneous, traumatic or post
operative.
7
o Carcinomatous meningitis that increased CSF viscosity fromhigh
protein content and excessive secretion due to a choroid plexus
papilloma.
Acute hydrocephalus occurs over days, subacute hydrocephalus occurs
over weeks, and chronic hydrocephalus occurs over months or years.
Conditions such as cerebral atrophy and focal destructive lesions also lead
to an abnormal increase of CSF in CNS. In these situations, loss of
cerebral tissue leaves a vacant space that is filled passively with CSF. Such
conditions are not the result of a hydrodynamic disorder and therefore are
not classified as hydrocephalus. An older misnomer used to describe these
conditions was hydrocephalus ex vacuo. (Rekate, 2009)
Normal pressure hydrocephalus (NPH) describes a condition that rarely
occurs in patients younger than 60 years. Enlarged ventricles and normal
CSF pressure at lumbar puncture (LP) in the absence of papilledema led to
the term NPH. However, intermittent intracranial hypertension has been
noted during monitoring of patients in whom NPH is suspected, usually at
night. The classic Hakim triad of symptoms includes gait apraxia,
incontinence, and dementia. (Rekate, 2009; Woodworth, 2009)
Congenital causes in infants and children (Garne, 2009)
o Brainstem malformation causing stenosis of the aqueduct of Sylvius:
This is responsible for 10% of all cases of hydrocephalus in newborns.
o Dandy-Walker malformation: This affects 2-4% of newborns with
hydrocephalus.
o Arnold-Chiari malformation type 1 and type 2
o Agenesis of the foramen of Monro
o Congenital toxoplasmosis
o Bickers-Adams syndrome: This is an X-linked hydrocephalus
accounting for 7% of cases in males. It is characterized by stenosis of
the aqueduct of Sylvius, severe mental retardation, and in 50% by an
adduction-flexion deformity of the thumb.
Acquired causes in infants and children (Alberto, 2000)
8
o Mass lesions: Mass lesions account for 20% of all cases of
hydrocephalus in children. These are usually tumors (eg,
medulloblastoma, astrocytoma), but cysts, abscesses, or hematoma also
can be the cause.[6]
o Hemorrhage: Intraventricular hemorrhage can be related to prematurity,
head injury, or rupture of a vascular malformation.
o Infections: Meningitis (especially bacterial) and, in some geographic
areas, cysticercosis can cause hydrocephalus.
o Increased venous sinus pressure: This can be related to achondroplasia,
some craniostenoses, or venous thrombosis.
o Iatrogenic: Hypervitaminosis A, by increasing secretion of CSF or by
increasing permeability of the blood-brain barrier, can lead to
hydrocephalus. As a caveat, hypervitaminosis A is a more common
cause of idiopathic intracranial hypertension, a disorder with increased
CSF pressure but small rather than large ventricles.
o Idiopathic
Causes of hydrocephalus in adults (Oertel, 2008)
o Subarachnoid hemorrhage (SAH) causes one third of these cases by
blocking the arachnoid villi and limiting resorption of CSF. However,
communication between ventricles and subarachnoid space is
preserved.
o Idiopathic hydrocephalus represents one third of cases of adult
hydrocephalus.
o Head injury, through the same mechanism as SAH, can result in
hydrocephalus.
o Tumors can cause blockage anywhere along the CSF pathways. The
most frequent tumors associated with hydrocephalus are ependymoma,
subependymal giant cell astrocytoma, choroid plexus papilloma,
craniopharyngioma, pituitary adenoma, hypothalamic or optic nerve
glioma, hamartoma, and metastatic tumors.
9
o Prior posterior fossa surgery may cause hydrocephalus by blocking
normal pathways of CSF flow.
o Congenital aqueductal stenosis causes hydrocephalus but may not be
symptomatic until adulthood. Special care should be taken when
attributing new neurological deficits to congenital hydrocephalus, as its
treatment by shunting may not correct these deficits.
o Meningitis, especially bacterial, may cause hydrocephalus in adults.
o All causes of hydrocephalus described in infants and children are
present in adults who have had congenital or childhood-acquired
hydrocephalus.
Causes of NPH (Most cases are idiopathic and are probably related to a
deficiency of arachnoid granulations.) (Alberto, 2000)
o SAH
o Head trauma
o Meningitis
2.5. Pathophysiology
Normal CSF production is 0.20-0.35 mL/min; most CSF is produced by
the choroid plexus, which is located within the ventricular system, mainly
the lateral and fourth ventricles. The capacity of the lateral and third
ventricles in a healthy person is 20 mL. Total volume of CSF in an adult is
120 mL.
Normal route of CSF from production to clearance is the following: From
the choroid plexus, the CSF flows to the lateral ventricle, then to the
interventricular foramen of Monro, the third ventricle, the cerebral
aqueduct of Sylvius, the fourth ventricle, the 2 lateral foramina of Luschka
and 1 medial foramen of Magendie, the subarachnoid space, the arachnoid
granulations, the dural sinus, and finally into the venous drainage.
ICP rises if production of CSF exceeds absorption. This occurs if CSF is
overproduced, resistance to CSF flow is increased, or venous sinus
pressure is increased. CSF production falls as ICP rises. Compensation
10
may occur through transventricular absorption of CSF and also by
absorption along nerve root sleeves. Temporal and frontal horns dilate
first, often asymmetrically. This may result in elevation of the corpus
callosum, stretching or perforation of the septum pellucidum, thinning of
the cerebral mantle, or enlargement of the third ventricle downward into
the pituitary fossa (which may cause pituitary dysfunction).
The mechanism of NPH has not been elucidated completely. Current
theories include increased resistance to flow of CSF within the ventricular
system or subarachnoid villi; intermittently elevated CSF pressure, usually
at night; and ventricular enlargement caused by an initial rise in CSF
pressure; the enlargement is maintained despite normal pressure because
of the Laplace law. Although pressure is normal, the enlarged ventricular
area reflects increased force on the ventricular wall.
2.6. Clinical Manifestation
Clinical features of hydrocephalus are influenced by the following
(Alberto, 2000):
Patient's age
Cause
Location of obstruction
Duration
Rapidity of onset
Symptoms in infants (Alberto, 2000) :
Poor feeding
Irritability
Reduced activity
Vomiting
Symptoms in children (Alberto, 2000) :
Slowing of mental capacity
Headaches (initially in the morning) that are more significant than in
infants because of skull rigidity
11
Neck pain suggesting tonsillar herniation
Vomiting, more significant in the morning
Blurred vision: This is a consequence of papilledema and later of optic
atrophy
Double vision: This is related to unilateral or bilateral sixth nerve palsy
Stunted growth and sexual maturation from third ventricle dilatation:
This can lead to obesity and to precocious puberty or delayed onset of
puberty.
Difficulty in walking secondary to spasticity: This affects the lower
limbs preferentially because the periventricular pyramidal tract is
stretched by the hydrocephalus.
Drowsiness
Symptoms in adults (Alberto, 2000) :
Cognitive deterioration: This can be confused with other types of
dementia in the elderly.
Headaches: These are more prominent in the morning because
cerebrospinal fluid (CSF) is resorbed less efficiently in the recumbent
position. This can be relieved by sitting up. As the condition progresses,
headaches become severe and continuous. Headache is rarely if ever
present in normal pressure hydrocephalus (NPH).
Neck pain: If present, neck pain may indicate protrusion of cerebellar
tonsils into the foramen magnum.
Nausea that is not exacerbated by head movements
Vomiting: Sometimes explosive, vomiting is more significant in the
morning.
Blurred vision (and episodes of "graying out"): These may suggest
serious optic nerve compromise, which should be treated as an
emergency.
Double vision (horizontal diplopia) from sixth nerve palsy
Difficulty in walking
Drowsiness
12
Incontinence (urinary first, fecal later if condition remains untreated):
This indicates significant destruction of frontal lobes and advanced
disease.
Symptoms of NPH (Alberto, 2000) :
Gait disturbance is usually the first symptom and may precede other
symptoms by months or years. Magnetic gait is used to emphasize the
tendency of the feet to remain "stuck to the floor" despite patients’ best
efforts to move them.
Dementia should be a late finding in pure (shunt-responsive) NPH. It
presents as an impairment of recent memory or as a "slowing of
thinking." Spontaneity and initiative are decreased. The degree can vary
from patient to patient.
Urinary incontinence may present as urgency, frequency, or a
diminished awareness of the need to urinate.
Other symptoms that can occur include personality changes and
Parkinsonism. Seizures are extremely rare and should prompt
consideration for an alternative diagnosis.
2.7. Diagnosis
Physical examination (Alberto, 2000)
Infants
o Head enlargement: Head circumference is at or above the 98 th
percentile for age.
o Dysjunction of sutures: This can be seen or palpated.
o Dilated scalp veins: The scalp is thin and shiny with easily visible
veins.
o Tense fontanelle: The anterior fontanelle in infants who are held
erect and are not crying may be excessively tense.
o Setting-sun sign: In infants, it is characteristic of increased
intracranial pressure (ICP). Ocular globes are deviated downward,
13
the upper lids are retracted, and the white sclerae may be visible
above the iris.
o Increased limb tone: Spasticity preferentially affects the lower limbs.
The cause is stretching of the periventricular pyramidal tract fibers
by hydrocephalus.
Children
o Papilledema: if the raised ICP is not treated, this can lead to optic
atrophy and vision loss.
o Failure of upward gaze: This is due to pressure on the tectal plate
through the suprapineal recess. The limitation of upward gaze is of
supranuclear origin. When the pressure is severe, other elements of
the dorsal midbrain syndrome (ie, Parinaud syndrome) may be
observed, such as light-near dissociation, convergence-retraction
nystagmus, and eyelid retraction (Collier sign).
o Macewen sign: A "cracked pot" sound is noted on percussion of the
head.
o Unsteady gait: This is related to spasticity in the lower extremities.
o Large head: Sutures are closed, but chronic increased ICP will lead
to progressive macrocephaly.
o Unilateral or bilateral sixth nerve palsy is secondary to increased
ICP.
Adults
o Papilledema: If raised ICP is not treated, it leads to optic atrophy.
o Failure of upward gaze and of accommodation indicates pressure on
the tectal plate. The full Parinaud syndrome is rare.
o Unsteady gait is related to truncal and limb ataxia. Spasticity in legs
also causes gait difficulty.
o Large head: The head may have been large since childhood.
o Unilateral or bilateral sixth nerve palsy is secondary to increased
ICP.
NPH
14
o Muscle strength is usually normal. No sensory loss is noted.
o Reflexes may be increased, and the Babinski response may be found
in one or both feet. These findings should prompt search for vascular
risk factors (causing associated brain microangiopathy or vascular
Parkinsonism), which are common in NPH patients.
o Difficulty in walking varies from mild imbalance to inability to walk
or to stand. The classic gait impairment consists of short steps, wide
base, externally rotated feet, and lack of festination (hastening of
cadence with progressively shortening stride length, a hallmark of
the gait impairment of Parkinson disease). These abnormalities may
progress to the point of apraxia. Patients may not know how to take
steps despite preservation of other learned motor tasks.
o Frontal release signs such as sucking and grasping reflexes appear in
late stages.
2.8. Radiology
The most important investigation is either a CT scan or MRI of the brain
which will show which ventricles are dilated. If the lateral ventricles and
3rd ventricles are all very dilated and 4th ventricle is small, the obstruction
at the level aqueduct of Sylvius. (Kaye, 2005)
Magnetic resonance imaging. In the sagital plane MRI is particularly
helpful in showing aqueduct. USG (Ultrasonography) through open
anterior fontanelle is useful in assesing ventricular size in infants and may
obviate the need for repeated CT scans. Plain skull X-ray can demonstrate
splayed suture, erosion of the bony buttresses around the tuberculum sellae
or a ‘copper beaten’ appeareance to the inside of the calvarium. (Kaye,
2005)
CT/MRI criteria for acute hydrocephalus include the following:
o Size of both temporal horns is greater than 2 mm, clearly visible. In the
absence of hydrocephalus, the temporal horns should be barely visible.
15
o Ratio of the largest width of the frontal horns to maximal biparietal
diameter (ie, Evans ratio) is greater than 30% in hydrocephalus.
o Transependymal exudate is translated on images as periventricular
hypoattenuation (CT) or hyperintensity (MRI T2-weighted and fluid-
attenuated inversion recovery [FLAIR] sequences).
o Ballooning of frontal horns of lateral ventricles and third ventricle (ie,
"Mickey mouse" ventricles) may indicate aqueductal obstruction.
o Upward bowing of the corpus callosum on sagittal MRI suggests acute
hydrocephalus.
CT/MRI criteria for chronic hydrocephalus include the following:
o Temporal horns may be less prominent than in acute hydrocephalus.
o Third ventricle may herniate into the sella turcica.
o Sella turcica may be eroded.
o Macrocrania (ie, occipitofrontal circumference >98th percentile) may be
present.
o Corpus callosum may be atrophied (best appreciated on sagittal MRI).
In this case, parenchymal atrophy and ex-vacuo (rather than true)
hydrocephalus from a neurodegenerative disease should be considered.
Ultrasonography through the anterior fontanelle in infants is useful for
evaluating subependymal and intraventricular hemorrhage and in
following infants for possible development of progressive hydrocephalus.
Radionuclide cisternography can be done in NPH to evaluate the prognosis
with regard to possible shunting. If a late scan (48-72 h) shows persistence
of ventricular activity with a ventricular to total intracranial activity (V/T
ratio) greater than 32%, the patient is more likely to benefit from shunting.
Because of its poor sensitivity in predicting shunt response when the V/T
ration is less than 32%, this test is no longer commonly used.
Skull radiographs may depict erosion of sella turcica, or "beaten copper
cranium" (called by some authors "beaten silver cranium"). The latter can
also be seen in craniosynostosis. (Larsson, 1990)
16
MRI cine is an MRI technique to measure CSF stroke volume (SV) in the
cerebral aqueduct. Cine phase-contrast MRI measurements of SV in the
cerebral aqueduct does not appear to be useful in predicting response to
shunting. (Kahlon, 2007)
Diffusion tensor imaging (DTI) is a novel imaging technique that detects
differences in fractional anisotropy (FA) and mean diffusivity (MD) of the
brain parenchyma surrounding the ventricles. Impairment of FA and MD
through DTI allows the recognition of microstructural changes in
periventricular white matter region that may be too subtle on conventional
MRI. (Hattigen, 2010)
2.9. Differential Diagnosis
Intracranial Hemorrhage
Pediatric idiopatic intracranial hypertension
Pseudotumor cerebri
Subdural Empyema
2.10. Treatment
Medical Care
Medical treatment in hydrocephalus is used to delay surgical
intervention. It may be tried in premature infants with posthemorrhagic
hydrocephalus (in the absence of acute hydrocephalus). Normal CSF
absorption may resume spontaneously during this interim period.
Medical treatment is not effective in long-term treatment of chronic
hydrocephalus. It may induce metabolic consequences and thus should
be used only as a temporizing measure.
Medications affect CSF dynamics by the following mechanisms:
o Decreasing CSF secretion by the choroid plexus - Acetazolamide
and furosemide
o Increasing CSF reabsorption - Isosorbide (effectiveness is
questionable)
17
Surgical Care
Surgical treatment is the preferred therapeutic option.[13]
Repeat lumbar punctures (LPs) can be performed for cases of
hydrocephalus after intraventricular hemorrhage, since this condition
can resolve spontaneously. If reabsorption does not resume when the
protein content of cerebrospinal fluid (CSF) is less than 100 mg/dL,
spontaneous resorption is unlikely to occur. LPs can be performed only
in cases of communicating hydrocephalus.
Alternatives to shunting include the following:
o Choroid plexectomy or choroid plexus coagulation may be effective.
o Opening of a stenosed aqueduct has a higher morbidity rate and a
lower success rate than shunting, except in the case of tumors.
However, lately cerebral aqueductoplasty has gained popularity as an
effective treatment for membranous and short-segment stenoses of
the sylvian aqueduct. It can be performed through a coronal
approach or endoscopically through suboccipital foramen magnum
trans-fourth ventricle approach.
o In these cases, tumor removal cures the hydrocephalus in 80%.
o Endoscopic fenestration of the floor of the third ventricle establishes
an alternative route for CSF toward the subarachnoid space. It is
contraindicated in communicating hydrocephalus.
Shunts eventually are performed in most patients. Only about 25% of
patients with hydrocephalus are treated successfully without shunt
placement. The principle of shunting is to establish a communication
between the CSF (ventricular or lumbar) and a drainage cavity
(peritoneum, right atrium, pleura). Remember that shunts are not
perfect and that all alternatives to shunting should be considered first.
18
o A ventriculoperitoneal (VP) shunt is used most commonly. The
lateral ventricle is the usual proximal location. The advantage of this
shunt is that the need to lengthen the catheter with growth may be
obviated by using a long peritoneal catheter.
o A ventriculoatrial (VA) shunt also is called a "vascular shunt." It
shunts the cerebral ventricles through the jugular vein and superior
vena cava into the right cardiac atrium. It is used when the patient
has abdominal abnormalities (eg, peritonitis, morbid obesity, or after
extensive abdominal surgery). This shunt requires repeated
lengthening in a growing child.
o A lumboperitoneal shunt is used only for communicating
hydrocephalus, CSF fistula, or pseudotumor cerebri.
o A Torkildsen shunt is used rarely. It shunts the ventricle to cisternal
space and is effective only in acquired obstructive hydrocephalus.
o A ventriculopleural shunt is considered second line. It is used if
other shunt types are contraindicated.
Rapid-onset hydrocephalus with increased intracranial pressure (ICP) is
an emergency. The following can be done, depending on each specific
case:
19
o Ventricular tap in infants
o Open ventricular drainage in children and adults
o LP in posthemorrhagic and postmeningitic hydrocephalus
o VP or VA shunt
Neuroendoscopy
Endoscopic surgical systems have undergone revolutionary changes in
the last two decades, thanks to technological advancements such as rod
lens systems, fiber optic technology, and better illumination with
powerful light sources and high resolution.
Neuroendoscopic systems can be divided into two main categories:
rigid and flexible endoscopes. These have different indications for use,
and each has its own advantages and disadvantages. In rigid
endoscopes,
the view angles vary from 0 to120 degrees. Those with 0-30 degree
view angles provide appropriate optical and anatomical orientation for
straightforward cases.
20
The outer diameters of rigid endoscopes are usually 3.8-6.2 mm, but
may be larger or smaller depending on the endoscope used. The main
advantages of rigid endoscopes over flexible endoscopes are better
image quality, wider and multiple working channels, stability, and
adaptability to stereotactic frames. The disadvantages of these
instruments are larger diameter and limited maneuverability. Flexible
endoscopes are thinner and less traumatic than rigid endoscopes. Their
outer diameter is 2.3·4.6 mm, and their main advantage is superior
maneuverability. The main disadvantages of these scopes are narrower
working channels and poor image quality.
The neuroendoscopic armamentarium has expanded continuously
during the last decade. The most widely used and specially designed
neuroendoscopic instruments are probe-perforators, Fogarty catheters,
biopsy and grasping forceps, scissors, mono- and bipolar cauteries,
suction tips, and laser wires (4,6). Although there are many specially
21
designed neuroendoscopic tools, most straightforward ETV procedures
can be performed with a few basic instruments.
The patient is placed in supine position and the head is elevated to 20-
30 degrees with slight flexion of the neck. This is done to prevent
postoperative pneumocephalus and reduce the risk of subdural
22
hematoma. An incision is made in the scalp and a burr-hole is drilled on
or just in front of the coronal suture on the mid-pupillary line. The
optimal entry point for ETVwas found as 8mm anterior to the coronal
suture and 28 mm lateral to the midline in a study. After a burr-hole of
approximately 1cm diameter is created, the dura is opened in cruciate
fashion and a peel-away cannula (12F) or rigid sheath (7 111m),
depending on the endoscopic system used, is introduced into the frontal
horn of the lateral ventricle. The endoscope is then passed through the
cannula into the frontal horn. The foramen of Monro is located by
following the choroid plexus, anterior septal, and thalamostriate veins,
and the endoscope is passed through this opening and placed into the
third ventricle. In normal subjects, the mean sagittal diameter of the
foramen of Monro is 2.9 mm and the vertical diameter is 5.1 mm. This
foramen is usually considerably enlarged in hydrocephalic patients, and
the endoscope can usually pass through easily without injuring the
fornix. Once the endoscope is in the third ventricle, the infundibular
recess, tuber cinereum, mamillary bodies, massa intermedia, aqueduct,
and posterior commissure can be observed from anterior to posterior.
The optic recess, lamina terminalis, and suprapineal recess can be seen
if the instrument is a wide angled rigid or flexible endoscope.
Fenestration is performed at the tuber cinereum at the midway between
the infundibular recess and the intermamillary point. Ideally, the site of
fenestration should be away from the basillary tip. onnally, the mean
distance between the infundibular recess and mamillary bodies is 6mm
(range,3.5-9mm). The mean distance between the basillary artery and
the infundibular recess in the normal setting is 10.5±2.3 mm, whereas
the corresponding distance in hydrocephalus patients is 12±3.7 mm. If
the ventricle floor is translucent, the basilar artery may be seen and
fenestration is performed distant from it. It is also critical to fenestrate
at the above-mentioned mid-point, because more lateral fenestration
may cause a third nerve injury.
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Fenestration of the floor of the third ventricle may be performed using a
blunt probe, Fogarty catheter, the endoscope itself, special scissors, a
coagubtor, or a number of other instruments, depending on the
surgeon's preference. We use an angled blunt probe designed for this
purpose, and angle the tip of the probe toward the dorsum sella so as
not to injure the basilar artery during fenestration. As mentioned above,
the floor of the ventricle is usually quite thin in patients with
hydrocephalus, and can be easily punctured with a blunt probe.
However, in some cases it may be relatively thick, and the surgeon may
prefer to use coagulation or sharp fenestration techniques in these cases.
However, I do not recommend using coagulation to fenestrate the floor,
as this may damage vascular structures below and may cause thermal
injury to the hypothalamus.
After the floor of the third ventricle is punctured, . the fenestrated site is
enlarged using a 3F Fogarty catheter. The catheter is passed through the
puncture hole, its balloon is inflated, and the catheter is then withdrawn
to enlarge the hole. Using this method, a fenestration of 5-6 mm
diameter is created. It is important to remember that the Fogarty
catheter may injure vascular structures and the third cranial nerve
below, and should not be advanced into the prepontine space too much.
The proximal end of the balloon should be visible to the surgeon. Once
this enlarged passageway is formed, the endoscope is inserted into the
prepontine space to explore the basilar artery and its tributaries, the
pons, the dorsum, and the clivus. It is not uncommon to observe a
second membrane, often connected to the Lilliquest membrane, in the
prepontine space. The main purpose of this exploration is to ensure
there is no other membrane obstructing free CSF flow in the prepontine
space. If there is such an obstructing membrane, it must also be
fenestrated with a blunt probe and enlarged with a Fogarty catheter, as
described above. After the prepontine space has been explored, the
endoscope is withdrawn into the third ventricle and the examiner will
24
observe pulsations of the floor along with "flapping" of the edges of the
newly created opening as CSF flows through indicating a patent
ventriculostomy.
It is not unusual to observe some bleeding during fenestration,
especially if the floor is thick and vascular. However, this is easily
stopped by irrigating the field with Ringer's lactate for awhile. Another
way to stop hemorrhage from the edges of the new opening is to inflate
the Fogarty balloon just at the level of the opening so that it compresses
the edges. The inflated balloon should be kept in place for 15-30
seconds. When the procedure is complete, the endoscope is withdrawn
slowly, exploring the third and lateral ventricles to ensure there is no
acti ve bleeding. A piece of Gelfoam® is placed in the burr-hole and the
scalp is closed in standard fashion. Some surgeons leave a ventricular
drain in place after ETV. The purpose of this is to measure intracranial
pressure (ICP) and be able to drain CSF if necessary. At our center, we
do not place a ventricular drain if there are no peroperative problems.
2.11. Prevention
There are no known ways to prevent all cases of hydrocephalus. In general
:
Get regular prenatal care.
Protect yourself or your child from head injuries.
Keep your child's vaccines up to date.
Preliminary research suggests that some cases due to brain bleeding in the
newborn period may be preventable. Cytomegalovirus or toxoplasmosis
acquired by a mother during pregnancy may be a cause of hydrocephalus
in a newborn baby. Mothers may reduce their risk of being infected with
toxoplasmosis with these steps:
Carefully cook meat and vegetables.
Correctly clean contaminated knives and cutting surfaces.
Avoid handling cat litter, or wear gloves when cleaning the litter box.
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Pet rodents (mice, rats, hamsters) often carry a virus called lymphocytic
choriomeningitis virus (LCV). LCV infection acquired from pets during
pregnancy can lead to hydrocephalus. This is preventable by avoiding
rodent contact. (Centers for Disease Control and Prevention, 2011)
Infection with Chickenpox or Mumps during or immediately after
pregnancy may also lead to hydrocephalus in the baby. Both of these
infections can be prevented with vaccination. Other preventable infections
may also cause hydrocephalus. People who have risk factors for
hydrocephalus should be carefully monitored. Immediate treatment might
prevent long-term complications. (Centers for Disease Control and
Prevention, 2011)
2.12. Prognosis
Long-term outcome is related directly to the cause of hydrocephalus. Up to
50% of patients with large intraventricular hemorrhage develop permanent
hydrocephalus requiring shunt. Following removal of a posterior fossa
tumor in children, 20% develop permanent hydrocephalus requiring a
shunt. The overall prognosis is related to type, location, and extent of
surgical resection of the tumor. Satisfactory control was reported for
medical treatment in 50% of hydrocephalic patients younger than 1 year
who had stable vital signs, normal renal function, and no symptoms of
elevated ICP.
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CHAPTER III
CLOSING
3.1. Conclusions
Hydrocephalus is a condition where in excess of cerebrospinal fluid
(CSF) accumulates within the ventricular system and cisterns of the
brain leading to increased intracranial pressure (ICP) and related
consequences. Hydrocephalus had multifactorial which can affect a
fetus, infant, child or adult. It can describe as imbalance between
production and absorption of CSF.
The aimed of treatment hyrocephalus was to evacuated the LCS or
remove the obstruction.
Long-term outcome is related directly to the cause of hydrocephalus.
27
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