Hydrocephalus

Question 1

What is hydrocephalus?

Answer 1

enlargement of the cerebral ventricular system.

Question 2

How is hydrocephalus subdivided?

Answer 2

Obstructive (non-communicating): Impaired outflow of CSF from the ventricular system
Non-obstructive (communicating): Impaired CSF reabsorption into subarachnoid villi

Question 3

What is Hydrocephalus ex vacuo?

Answer 3

apparent enlargement of the ventricles as a compensatory change due to brain atrophy
NOT a true hyrocephalus

Question 4

List 3 causes of non-obstructive hydrocephalus

Answer 4

Tumours
Meningitis
Normal Pressure Hydrocephalus: idiopathic chronic ventricular enlargement. Long white matter tracts are damaged leading to gait + cognitive decline

Question 5

List 3 causes of obstructive hydrocephalus

Answer 5

Lesions of the 3rd + 4th ventricle or cerebral aqueduct
Posterior fossa lesions (e.g. tumour) compressing the 4th ventricle
Cerebral aqueduct stenosis

Question 6

Which age groups are effected by hydrocephalus most commonly?

Answer 6

Bimodal age distribution
YOUNG: congenital malformations + brain tumours
ELDERLY: strokes + tumours

Question 7

Obstructive Hydrocephalus causes which 2 symptoms?

Answer 7

Acute drop in conscious level

Diplopia

Question 8

Normal Pressure Hydrocephalus causes what 3 symptoms?

Answer 8

Urinary incontinence WET
Falls WOBBLY
Chronic cognitive decline (dementia) WACKY

Question 9

List 3 signs seen in obstructive hydrocephalus

Answer 9

Low GCS
Papilloedema
6th nerve palsy (longest intracranial path of all CN’s so is most susceptible to palsy due to raised ICP)

Question 10

List 2 signs of obstructive hydrocephalus in neonates

Answer 10

Increased head circumference  
Sunset sign (downward conjugate deviation of the eyes)

Question 11

List 3 signs of normal pressure hydrocephalus

Answer 11

Cognitive impairment
Gait apraxia (shuffling, difficulty lifting feet off floor)
Hyperreflexia

Question 12

What is the first line investigation to perform in hydrocephalus?

Answer 12

CT Head
To detect hydrocephalus
May also pick up the cause (e.g. tumour)

Question 13

What other investigations should be performed in hydrocephalus?

Answer 13

CSF: From ventricular drain or LP. May indicate pathology (e.g. TB). Check MC+S, protein + glucose (CSF + plasma)
LP: contraindicated if raised ICP. Therapeutic in NPH