Diseases of CNS

Diseases of CNSBy

Dr. Abdelaty Shawky Dr. Gehan Mohamed

Topics:1. Hydrocephalus.2. Cerebrovascular diseases.3. Brain abscess.4. Neurodegenerative diseases.5. Brain tumors.

Hydrocephalus

ILOs

1. Understanding definition of hydrocephalus.2. Discussing causes of hydrocephalus.3. Describing morphological features of

hydrocephalus.4. Being aware of the complications of

hydrocephalus.

* Def: Dilation of ventricular system due to excess C.S.F volume associated with atrophy of the brain tissue..* Causes:I. Increased CSF production: choroid plexus papilloma or choroiditis. II. Obstruction of CSF flow:a. Congenital causes: 1. Narrowing of foramina of the ventricles or aqueduct of sylvius.

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Normal ventricles and hydrocephalus

2. Arnold - Chiari malformation: down-word displacement of medulla and cerebellum into foramen magnum with block of the foramina of fourth ventricle.b. Acquired causes: due to post-meningitis fibrosis or space occupying lesions.

III. Defective absorption through arachnoid villi: • Congenital causes: agenesis or hypoplasia of arachnoid

villi.• Acquired causes: arachnoid villi fibrosis – superior

saggital sinus thrombosis.

* Types:

1. Communicating Hydrocephalus: When obstruction occur outside the ventricular system.2. Non communicating Hydrocephalus: When obstruction occurs within the ventricles.3. Hydrocephalus Ex vacu: Refers to dilatation of ventricular system with compensatory increase in CSF volume secondary to brain atrophy.

* Morphology:• Dilated ventricles.• Increased C.S.F pressure leads to peri-ventricular interstitial

edema.• Pressure atrophy of the brain tissue.• Skull changes:A. Children:– Thin bone.– Separated sutures.– Enlarged skull.– Mental deficiency.

B. Adult:– The inner vault of the skull shows varying degrees of convolutional

markings (mouse eaten appearance).

* Signs and Symptoms:• Symptoms of increased intracranial pressure:

include: Headache.Vomiting.Nausea.Papilledema.Sleepiness or coma. Cerebellar tonsill herniation, with resulting life

threatening brain stem compression.

• Early symptoms may also include:Eyes that appear to gaze downward

(Sundowning)IrritabilitySeizures

• Symptoms that may occur in older children can include:

• Changes in personality, memory, or the ability to think• Changes in facial appearance and eye spacing• Uncontrolled eye movements• Difficulty feeding• Excessive sleepiness• Headache• Irritability• Loss of bladder control (urinary incontinence)• Loss of coordination and trouble walking• Muscle spasticity (spasm)• Slow growth• Slow or restricted movement• Vomiting

Sunset appearance of the eye due to paresis of upward gaze secondary to increase in intracranial pressure

* Treatment: - Hydrocephalus treatment is surgical.• Cerebral shunts: It involves the placement of a

ventricular catheter, into the cerebral ventricles to bypass the flow obstruction/malfunctioning arachnoidal granulations and drain the excess fluid into other body cavities, from where it can be resorbed.

• Most shunts drain the fluid into the peritoneal cavity (ventriculo-peritoneal shunt), but alternative sites include the right atrium (ventriculo-atrial shunt), pleural cavity (ventriculo-pleural shunt), and gallbladder.

* Shunt complications:

1. Shunt infection.2. Shunt malfunction.3. Shunt failure.

• Other treatments may include:• Antibiotics are given if there are signs of

infection. Severe infections may require the shunt to be removed.

• Follow up: The child will need regular check-ups to make sure there are no further problems. Tests are regularly done to check the child's developmental and for intellectual, neurological, or physical problems.