Hydrocephalus and raised ICP

Question 1

What is hydrocephalus

Answer 1

Accumulation of cerebrospinal fluid in the ventricles typically leading to raised ICP

Question 2

What is idiopathic intracranial hypertension

Answer 2

a disorder of increased intracranial pressure in an alert and orientated patient, without a detectable cause

Question 3

Give 3 RFs of idiopathic intracranial hypertension

Answer 3

• Female
• Obesity/ weight gain
• Drugs

Question 4

Name 4 drugs that increase the risk of idiopathic intracranial hypertension

Answer 4

• COCP
• tetracyclines
• steroids
• lithium
• retinoids/ vitamin a

Question 5

Describe the clinical features of idiopathic intracranial hypertension

Answer 5

• blurred vision, enlarged blind spot
• Headache - throbbing and severe
• Transient loss of vision for <30 seconds
• Pulse synchronous tinnitus
• Papilledema
• 6th nerve palsy

Question 6

Name the diagnostic criteria for idiopathic intracranial hypertension

Answer 6

Modified Dandy criteria

Question 7

What investigations should be ordered for idiopathic intracranial hypertension

Answer 7

• Visual field test
• Fundoscopy
• MRI brain - transverse sinus stenosis
• LP at L3/4 - raised pressure

Question 8

How is idiopathic intracranial hypertension managed

Answer 8

• Lifestyle: Weight reduction, assess meds
• Meds: Carbonic anhydrase inhibitor (e.g. Acetazolamide)
• topiramate
• repeated lumbar puncture
• surgery: optic nerve sheath decompression

Question 9

What is normal pressure hydrocephalus (NPH)

Answer 9

A type of hydrocephalus where the amount of CSF in the brain increases, but the pressure of the fluid is usually normal

Question 10

Describe the clinical features of normal pressure hydrocephalus

Answer 10

• Levodopa-unresponsive gait abnormality
• Cognitive impairment - dementia, bradyphrenia
• urinary incontinence

Question 11

What is a levodopa-unresponsive gait apraxia

Answer 11

• Inability to walk in standing position, while able to make walking movements while lying
• Characterised by: a slow, cautious gait; gait initiation failure; unsteadiness; falls and freezing

Question 12

Give 3 RFs of normal pressure hydrocephalus

Answer 12

• Over 65
• Vascular disease
• DM

Question 13

How is normal pressure hydrocephalus diagnosed

Answer 13

• NCCT/ MRI head - ventricular enlargement in the absence of, or out of proportion to, sulcal enlargement
• Levodopa challenge - no response to therapy
• LP - normal CSF pressure

Question 14

How is normal pressure hydrocephalus managed

Answer 14

Ventriculoperitoneal shunting

Question 15

Give 5 causes of raised ICP

Answer 15

• Brain tumours
• Haemorrhage
• Idiopathic intracranial hypertension
• Abscess or infection
• hydrocephalus

Question 16

Give 5 features of raised intracranial pressure

Answer 16

• headache
• vomiting
• reduced levels of consciousness
• papilloedema
• Cushing’s triad: widening pulse pressure, bradycardia, irregular breathing

Question 17

How is raised intracranial pressure managed

Answer 17

• investigate and treat the underlying cause
• head elevation to 30º
• IV mannitol may be used as an osmotic diuretic
• controlled hyperventilation
• removal of CSF

Question 18

How is papilloedema seen on fundoscopy

Answer 18

• venous engorgement: usually the first sign
• Blurring of optic disc margin
• Elevated optic disc and loss of optic cup
• loss of venous pulsation
• Paton’s lines (folds in the retina around the optic disc)