Abstract
A detailed clinical study of 105 CPH attacks in five patients has been carried out. Data were recorded during periods when patients were without medication and with the use of methods which were not dependent on the patients' memory of events. When overall assessments of symptoms during the study period were mild or moderate the attack frequency was from 4 to 8, mean 6.5 attacks per 24 h. However, when overall assessments of symptoms were described as severe or extremely severe the attack frequency was from 13 to 38, mean 21.8 attacks per 24 h. The mean duration of attacks was 13.3 ± 7.6 min. No nocturnal preponderance of attacks was found.