Symptoms

Severe headache that prevents patients from carrying out activities of daily living

“Patients commonly describe their headache as pressing, explosive with a frontal, retroorbital localization”

High hospital admission rate of 38%

Papilledema (bilateral optic nerve swelling) can be progressive and lead to enlargement of blind spots

Common visual disturbances include blurred vision, visual obscurations and loss of vision

Cerebrospinal Fluid (CSF) normal pressure is <25cm H20
IIH – abnormally high pressure >25 cm H20
Acute IIH can be fatal if not treated promptly as a medical emergency, while chronic IIH is generally a lifelong condition

From: European Headache Federation guideline on idiopathic intracranial hypertension

IIH Diagnostic criteria
  1. Papiloedema
  2. Normal neurological examination (except sixth cranial nerve palsy)
  3. Neuroimaging: normal brain parenchyma (no hydrocephalus, mass, structural lesion or meningeal enhancement). Venous thrombosis excluded in all.
  4. Normal CS constituents
  5. Elevated lumbar puncture pressure ≥ 25cmCSF

IIH without Papilloedema (IIHWOP) Diagnostic criteria

Presence of criteria B-E for IIH plus:

  • Unilateral or bilateral sixth cranial nerve palsy


Suggestion of possible lIHWOP if:
Presence of criteria B-E for IIH plus:

  • 3 neuroimaging finding suggestive of raised intracranial pressure
    • Empty sella
    • Flattening of posterior aspect of the globe
    • Distention of the perioptic subarachnoid space ± a tortuous optic nerve
    • Transverse venous sinus stenosis

 

Diagnostic criteria for IIH (commonly referred to as the Friedman criteria).

The above graphic illustrates the diagnostic criteria for IIH and IIH without papilledema. Normal lumbar pressure is indicated in the blue area. When lumbar pressure is between 25 and 30 cm of cerebral spinal fluid (the gray area), it can represent normal pressure in some individuals, but can indicate pathologically raised intracranial pressure in other individuals. Measurements in the grey zone need to be interpreted with caution and patients must fit the other criteria for IIH for a diagnosis to be confirmed. Individuals with pressure in the red area have elevated lumbar pressure and have IIH if they meet the above-noted criteria.