Idiopathic intracranial Hypertension

Question 1

Risk factors for idiopathic intracranial hypertension

Answer 1

Young female
Obesity
Pregnancy
Drugs: COCP, steroids, tetracyclines, retinoids, lithium

Question 2

Symptoms of idiopathic intracranial hypertension

Answer 2

Headache
- Worse in the morning or when bending over or coughing
Blurred vision
Enlarged blind spot
Sixth nerve palsy
Early morning nausea/vomiting
Transient visual obscuration
Pulse-synchronous tinnitus
Photophobia
Retrobulbar pain
Diplopia

Question 3

Signs of idiopathic intracranial hypertension

Answer 3

Fundoscopy
Sixth nerve palsy
Enlarged blind spot

Question 4

Investigations for idiopathic intracranial hypertension

Answer 4

Visual field/fundoscopy

MRI brain: exclude mass lesions, look for:
Transverse sinus stenosis
Empty sella
Posterior pituitary stalk displacement
Posterior globe flattening
Tight subarachnoid spaces

LP: Pressure elevated >250

Question 5

Management for idiopathic intracranial pressure

Answer 5

Weight loss
- Diet and exercise
- Semglitide
- Topiramate (also inhibits carbonic anhydrase)
Medication
- Analgesia e.g. amitriptyline, naproxen
- Carbonic anhydrase inhibitors e.g. acetazolamide, topiramate (causes weight loss)
Surgery: indicated in visual loss
- Repeated LP
- Optic nerve sheath decompression and fenestration may be needed to prevent damage to the optic nerve.
- Lumboperitoneal or ventriculoperitoneal shunt may also be performed to reduce intracranial pressure
- For tinnitus -> transverse sinus stenting

Question 6

Complications and prognosis of idiopathic intracranial hypertension

Answer 6

Irreversible vision loss

Either self-limiting or lifelong chronic course
50% of patients have marked improvement in visual field function with treatment