Hydrocephalus Presaented - PowerPoint Presentation

Slide1

Hydrocephalus

Presaented

by :

Faisal

Hussain

.

Majid

Ahmed .

Lecture Objective :

Definition

Epidemiology.

Anatomy and Physiology

Classification .

Pathogenesis .

Etiology .

Clinical feature .

Diagnosis

Management .

Definition and Epidemiology :

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.

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:

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.

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

Pathology:

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-I

flattening 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.

chronic hydrocephalus

the force of the fluid is distributed over the greater surface area of the enlarged ventricular system

Etiology :

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

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:

Symptoms in infantsPoor feedingIrritabilityReduced activityVomiting

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

Signs :

ChildrenPapilledema: 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 light-near 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.

Infants

Head enlargement: Head circumference is at or above the 98

th

 percentile for age.

Dysjunction

of sutures: This can be seen or palpated.

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.

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

.

Differential Diagnosis :

Intracranial Hemorrhage

Intracranial Epidural Abscess

Epidural Hematoma

Subdural

Empyema

Subdural Hematoma

Brainstem

Gliomas

Meningioma

Pseudotumor

Cerebri

: Pediatric Perspective

Pituitary Tumors

Management :

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

Medical Management :

Diuretics .

Fibrinolytic

therapy .

Serial lumbar punctures .