Headache profiles in patients with a dilatated cyst of the cavum septi pellucidi

The dilatated cyst of the cavum septi pellucidi (CSP) is rare and may be associated with headaches. We reviewed the computerized database of 54,000 patients' computed tomography or magnetic resonance images and found 22 cases (0.04%) involving a dilatated cyst of the CSP. Sixteen patients had a chief complaint of headache, which was classified as acute episodic headache (type I, n = 7, 43.7%), chronic daily headache (CDH) with acute onset (type II, n = 5, 31.3%), or CDH with insidious onset (type III, n = 4, 25%). Acute Valsalva-induced headaches were common with type I (85%) or II (100%); 70% of these responded to indomethacin. At follow-up, patients with type I headache had the highest remission rate (71%), and type III patients the lowest (0%). Dilatated cysts of the CSP should be considered a cause of acute Valsalva-induced headache or new daily persistent headache, and may respond to indomethacin. A protracted course (> or = 3 months) indicates a worse outcome.