Chronic paroxysmal hemicrania: dissociation of the pain and autonomic features.

The case of a woman suffering from chronic paroxysmal hemicrania is presented. Most attacks were unilateral and recurred on the same side. On a few occasions, attacks were observed on the contralateral side. In addition, the patient reported some incomplete attacks on the usually symptomatic side with autonomic phenomena, but without pain. That "partial" attacks would exist has been suspected on theoretical ground. This is, however, the first time such attacks have been reported by a patient. Therefore, a double dissociation of the symptomatology seemed to exist: (1) a side shift of attacks, and (2) incomplete ("partial") attacks. These unexpected findings occurred after two indomethacin treatment withdrawals. A possible central and "midline" origin of attacks or an indomethacin after-effect or both are discussed as a likely explanation for such a dissociation of symptoms and signs.