Transcript Slide 1

HYDROCEPHALUS
Presaented by :
Faisal Hussain .
Majid Ahmed .
Lecture Objective :
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Definition
Epidemiology.
Anatomy and Physiology
Classification .
Pathogenesis .
Etiology .
Clinical feature .
Diagnosis
Management .
Definition and Epidemiology :
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Definition :
Hydrocephalus is a disorder in which the cerebral ventricular
system contains an excessive amount of cerebrospinal fluid
(CSF) and is dilated because of increased pressure.
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Epidemilogy:
The prevalence of congenital and infantile hydrocephalus has
been estimated as 0.48 to 0.81 per 1000 live and still births
Anatomy:
Physiology:
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CSF Production:
site: choroid pluxes
Amount : 20ml/h .
Rate: 0.1 to 26 ml/h . wich affected by : age and weight
Total volume : Range from 50 to 150 ml .
CSF produced by active secretion and diffusion.
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CSF Absorption :
CSF is absorbed into the systemic circulation primarily across the arachnoid
villi into the venous channels of the sagittal sinus
Classification :
Non communicating (obstructive )
The obstruction occurs at the Interventricular foramina, the
aqueduct of Sylvius, or the fourth ventricle and its
outlets .
Note: The proximal area of ventricle system is diliated .
 Communicating (non obstructive);
due to :
1- decrease absorption : inflammation of the
subarachnoid villi .
2- increased secretion .e.g choroid pluxes papilloma
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Pathology:
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Acute obstruction :
1- causes increased pressure and rapid enlargement of the ventricular system.
The frontal and occipital horns of the lateral ventricles enlarge first. Symmetric
dilatation of the remainder of the intracerebral CSF-containing spaces follows.
2-Iflattening of the gyri and compression of the sulci against the cranium,
3-obliterating the subarachnoid space over the hemispheres.
4-The vascular system is compressed, and the venous pressure in the dural sinuses
increases.
5-. contributes to the development of interstitial edema of the periventricular white
matter.
6-Another compensatory mechanism that limits expansion of the ventricular system
in infants is spreading of the cranial sutures.
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chronic hydrocephalus
the force of the fluid is distributed over the greater surface area of the enlarged
ventricular system
Etiology :
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Congenital :
A - Neural tube defect : e.g myelomeningocele has the following
1- obstruction of fourth ventricular outflow
2- flow of CSF through the posterior fossa due to the Chiari malformation
3- aqueductal stenosis .
B- Isolated hydrocephalus :
aqueductal stenosis in wich this stenosis may due to malformation or inflamation .
c- X-linked hydrocephalus :
aqueductal stenosis
D- CNS malformation : 1- Chiari II portions of the brainstem and cerebellum are displaced
caudally into the cervical spinal canal. This obstructs the flow of CSF in the posterior fossa
2- Dandy Walker syndrome :atresia of the foramine of
Luschka and Magendie
3- Vein of Galen malformation : compression of the cerebral aqueduct .
Etiology : continued
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Congenital continued :
E- Intrauterine infection . rubella, cytomegalovirus,
toxoplasmosis, and syphilis
F- Syndromi Hydrocephalus : 13 ,18 ,9
Acquired :
1- Infection e.g. meningites and encephalities .
2- Tumor : especially posterior fossa medulloblastomas,
astrocytomas, and ependymomas.
3- hemorrhage :a- subarachnoid space
b- into the ventricular system
Symptoms:
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Symptoms in children
Slowing of mental capacity
Headaches (initially in the morning) that are more significant than in
infants because of skull rigidity
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.(hypothalmous)
Difficulty in walking secondary to spasticity: This affects the lower
limbs preferentially because the periventricular pyramidal tract is
stretched by the hydrocephalus.
Drowsiness
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Symptoms in
infants
Poor
feeding
Irritability
Reduced
activity
Vomiting
Signs :
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Infants
Head enlargement: Head circumference is
at or above the 98th percentile for age.
Dysjunction of sutures: This can be seen or
palpated.
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Dilated scalp veins: The scalp is thin and
shiny with easily visible veins.
Tense fontanelle: The anterior fontanelle
in infants who are held erect and are not
crying may be excessively tense.
Setting-sun sign: In infants, it is
characteristic of increased intracranial
pressure (ICP). Ocular globes are
deviated downward, the upper lids are
retracted, and the white sclerae may be
visible above the iris.
Increased limb tone: Spasticity
preferentially affects the lower limbs.The
cause is stretching of the periventricular
pyramidal tract fibers by hydrocephalus.
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Children
Papilledema: if the raised ICP is not treated,
this can lead to optic atrophy and vision loss.
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 lightnear dissociation, convergence-retraction
nystagmus, and eyelid retraction (Collier
sign).
Macewen sign: A "cracked pot" sound is
noted on percussion of the head.
Unsteady gait: This is related to spasticity in
the lower extremities.
Large head: Sutures are closed, but chronic
increased ICP will lead to progressive
macrocephaly.
Unilateral or bilateral sixth nerve palsy is
secondary to increased ICP.
Diagnosis :
Serial head measurement .
 The diagnosis is confirmed by neuroimaging
In a newborn, ultrasonography is the preferred
technique due to mobility and has no radition .
Infant and children CT and MRI .
 A lumbar puncture (LP) should be performed in case
of meningities or encephalities .
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Differential Diagnosis :
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Intracranial Hemorrhage
Intracranial Epidural Abscess
Epidural Hematoma
Subdural Empyema
Subdural Hematoma
Brainstem Gliomas
Meningioma
Pseudotumor Cerebri: Pediatric Perspective
Pituitary Tumors
Management :
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Shunt :
RT lateral ventricle to peritoneum .
The catheter is connected to a one-way valve system
Complication :
1-Infection: Staphylococcus epidermidis , S. aureus,
enteric bacteria, diphtheroids, and Streptococcus
species.
2- malfunction .
Management : continued
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Medical Management :
Diuretics .
Fibrinolytic therapy .
Serial lumbar punctures .