Chronic migrainous neuralgia: a variant of cluster headache.

A series of 101 patients suffering from cluster headache is examined in this paper. Ninety-five of these patients suffered from the periodic form of the disorder and in clinical symptomatology differed little from the many previous reports in the literature. As in other series, the condition was seldom diagnosed when the patient presented to the clinic. Six patients had a different pattern. In these there was no brief cluster, but rather a continuous period of once- or twice-daily attacks of migrainous neuralgia without apparent spontaneous remission. Both primary and secondary types of chronic migrainous neuralgia are recognized: in the latter instance attacks which were at first periodic later changed to the continuous or chronic form. In these patients the attacks were less responsive to ergotamine and methysergide than are patients with the periodic cluster headache, although individually useful periods of control of symptoms were obtained with these drugs. The use of lithium in three patients provided continuous control when the drug was used in low dosage, and no side-effects were observed.