A patient recovering from lateral sinus thrombophlebitis complicating CSOM develops headache, vomiting, bilateral papilloedema and a lucid conscious state. Lumbar puncture shows raised opening pressure with normal CSF constituents. The mechanism of this condition is:

• A Impaired CSF absorption caused by raised pressure in the thrombosed dural venous sinuses ✓
• B Obstruction of CSF flow at the aqueduct of Sylvius by inflammatory exudate
• C Increased CSF production by choroid plexus inflammation
• D Venous infarction of the parietal cortex with surrounding oedema

Explanation

Otitic hydrocephalus results from lateral sinus thrombosis propagating to the superior sagittal sinus, raising venous pressure and reducing arachnoid granulation absorption of CSF. Intracranial pressure rises while CSF protein, cells and glucose remain normal, distinguishing it from meningitis or brain abscess. It typically follows lateral sinus thrombosis in adolescents and presents with papilloedema without focal neurological deficits.

Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.

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Written and medically reviewed by the StethoPrep medical team.