Idiopathic increase in intracranial pressure with no evidence of an underlying structural brain pathology, although thought to be due to inadequate absorption of CSF in the arachnoid villi.

Commonly encountered in obese women of child bearing age 

Papilloedema. 6th nerve palsy may also be seen [false localizing sign]

Headache worse with coughing, sneezing, bending down, visual obscurations (sometimes worse on bending down), pulsatile tinnitus 

Bloods: FBC, ESR, haemotinics, coagulation and ANA. 

Imaging: CT/MRI to exclude structural brain lesions 

Special Tests: Lumbar puncture shows an elevated CSF opening pressure

Humphrey’s visual fields should be performed to assess for defects.

Conservative: Weight loss

Medical: Lumbar puncture to reduce CSF pressure or Acetazolamide

Surgical: Optic nerve fenestration or lumbo-peritoneal shunt procedure 

10% have progressive visual loss an optic atrophy

Visual loss