Transient visual obscurations and headache in aqueduct stenosis exacerbated by menstruation.

The influence of female sex hormones is implicated in the pathogenesis of benign intracranial hypertension, but their effect on intracranial pressure (ICP) in other settings is not known. We report a 23-year-old white female with catamenial exacerbations of transient visual obscurations and headache suggestive of raised ICP. The patient had obstructive hydrocephalus secondary to stenosis of the aqueduct of Sylvius associated with a Chiari type I malformation. Exacerbation of raised ICP during the menstrual period was the most likely cause of her symptoms. Female sex hormones may influence the secretion or absorption of cerebrospinal fluid in conditions other than BIH.