Chronic paroxysmal hemicrania: the first possible bilateral case.

There are three headaches syndromes that are typically characterized by strictly unilateral and always same-sided attacks: cluster headache, "cervicogenic" headache, and chronic paroxysmal hemicrania (CPH). In rare cases, cluster headache also occurs bilaterally; "cervicogenic" headaches probably as well. We present a patient with a probable bilateral CPH. To our knowledge no such case has previously been described.