Chronic paroxysmal hemicrania. XIII. The pupillometric pattern.

Pupillometric studies were carried out in eight patients with chronic paroxysmal hemicrania (CPH) and in age- and sex-matched controls in the basal condition and after instillation of 2% tyramine (CPH, n = 5; controls, n = 17), 1% OH-amphetamine (CPH, n = 6; controls, n = 12), and 1% phenylephrine (CPH, n = 6; controls, n = 17). The pupil on the symptomatic and non-symptomatic sides in CPH patients was significantly smaller in the basal condition than in controls, particularly on the symptomatic side. The mydriatic responses to pharmacologic stimulation were essentially similar on the symptomatic and non-symptomatic sides. An evaporimetric study of the forehead sweat glands, using the body heating and pilocarpine tests, was also carried out in these patients and in age- and sex-matched controls. "Early", "intermediate", and "late" measurements demonstrated symmetry of forehead sweating. The findings for both methods of examination thus contrast with those in cluster headache patients. Pupillometric and forehead sweating patterns therefore suggest differences in the pathogenesis of the two headache entities. These tests may be used to distinguish CPH and cluster headache clinically.