Therapeutic effectiveness of acetazolamide in hindbrain hernia headache.

A 43-year-old man had been suffering from exertional headache for 10 years. Sagittal sections on magnetic resonance imaging showed a Chiari type 1 malformation and a cerebellar arachnoid cyst. This syndrome, named hindbrain hernia headache, disappeared with oral acetazolamide. This treatment should be tried in patients with hindbrain hernia headache prior to considering surgical decompression of the foramen magnum.