More precise phenotyping of cluster headache using prospective attack reports.

BACKGROUND AND PURPOSE: The clinical characteristics of cluster headache (CH) are based mainly on retrospective attack descriptions of 'usual' attacks, but whether these reports are reliable is uncertain. The aim was to compare retrospective and prospective attack descriptions and describe the within- and between-patient variability of attacks. METHOD: Fifty-seven CH patients underwent a semi-structured interview obtaining a retrospective account of usual CH attacks. Patients thereafter prospectively recorded the clinical characteristics of up to 10 attacks per patient in a headache diary. Four different attack characteristics were investigated: (i) severity, (ii) duration, (iii) number of autonomic symptoms and (iv) number of migrainous symptoms. Retrospective and prospective data were compared. Within- and between-patient variability of attacks was assessed. RESULTS: Retrospective attack descriptions (n = 57) were significantly longer (P = 0.046) and more severe (P < 0.0001) for untreated attacks compared with prospective reports (n = 500). The number of autonomic symptoms was significantly higher in the retrospective reports compared to the prospective reports (P < 0.0001). Within-patient variability for attack duration, pain severity and number of autonomic and migrainous symptoms was low. Compared to men, more women reported longer (P = 0.026) and more severe (P = 0.028) attacks with more migrainous symptoms (P = 0.033). CONCLUSIONS: Important differences were found between prospectively and retrospectively reported attacks with duration and severity of untreated attacks overestimated in retrospective attack descriptions. CH attacks display low within-patient variability, but the presentation of CH attacks varies between patients. The high prevalence of symptoms typically associated with migraine should raise more diagnostic awareness for CH, especially in women who are more often misdiagnosed as having migraine.

Disturbed sleep in cluster headache is not the result of transient processes associated with the cluster period.

BACKGROUND AND PURPOSE: Cluster headache (CH) is characterized by severe, unilateral attacks of pain and a high nocturnal attack burden. It remains unknown whether perturbations of sleep are solely present during the CH bout. Therefore, we aimed to investigate differences in sleep between the bout and remission period in patients with episodic CH and, secondly, to compare patients in the two phases with controls. METHODS: Patients with episodic CH (aged 18-65 years), diagnosed according to the International Classification of Headache Disorders 2nd edition, were admitted for polysomnography at the Danish Center for Sleep Medicine in bout and in remission. The macrostructure of sleep, including arousals, breathing parameters, limb movements and periodic limb movements, was compared with 25 age-, sex- and body mass index-matched healthy controls. RESULTS: There were no differences in any of the sleep parameters for patients in bout (n = 32) compared with patients in remission (n = 23). Attacks were unrelated to sleep stages, presence of apnea episodes, periodic limb movements, limb movements and arousals. In bout, patients had longer sleep latency (18.8 vs. 11.7 min, P < 0.05) and rapid eye movement sleep latency (1.7 vs. 1.2 h, P < 0.05) than controls and sleep efficiency was lower (82.5% vs. 86.5%, P < 0.05). Patients in remission only had a longer sleep latency compared with controls (17.5 vs. 11.7 min, P < 0.01). CONCLUSIONS: The results support the presence of a continuing or slowly recovering disturbance of sleep outside the bout rather than a disturbance occurring secondary to attacks. Further, we confirm that there is no relation between CH attacks and specific sleep stages or between CH and breathing parameters.