19th June 2023

Diagnosis

• Idiopathic intracranial hypertension (IIH) is a rare condition resulting in increased intracranial pressure without underlying cause, such as hydrocephalus or a mass lesion. CSF composition is also normal. It is also termed Benign Intracranial Hypertension. It mostly affects young women and has a strong association with obesity.
• Clinical features include:
  • Headache with increasing severity and frequency. Headache typically worse on waking and on performing manoeuvres which increase intracranial pressure (ICP), such as bending over.
  • Visual disturbance or loss, horizontal diplopia due to abducens nerve (CNVI) palsy, reduced peripheral vision, blurred vision with loss of acuity and colour sensitivity, momentary darkening of vision on standing or bending (visual obscuration).
  • Pulsatile tinnitus, dizziness, mild cognitive disturbance, and upper cervical or radicular back pain
  • On examination, there may be oculomotor nerve palsies, papilloedema or optic atrophy.

Idiopathic Intracranial Hypertension diagnostic criteria:

1. Papilloedema
2. Normal neurological examination (except 6th CN palsy)
3. Normal brain parenchyma on imaging with no evidence of hydrocephalus, mass lesion or venous thrombosis.
4. Normal CSF composition
5. Raised opening pressure on lumbar puncture ≥ 25cm

IIH without papilledema (IIHWOP) diagnostic criteria:

1. Normal neurological examination
2. Normal neuroimaging
3. Normal CSF composition
4. Raised opening pressure on lumbar puncture ≥ 25cm
5. Unilateral or bilateral 6th cranial nerve palsy