The typical cyclic occurrence of
cluster headache suggests the involvement of hypothalamic rhythm regulating centers in the pathogenesis of this primary
headache. In previous studies, reduced 24-h plasma
melatonin levels during the cluster period, loss of circadian
melatonin secretion in remission, as well as permanently reduced excretion of urinary
melatonin in both illness phases have been reported, supporting the hypothesis of a hypothalamic derangement. In this study, the 24-h urinary excretion of the main
melatonin metabolite,
6-sulphatoxymelatonin, was evaluated in 20 cluster period
cluster headache patients. Thirteen were retested 12 months later, in the same period of the year, during remission. Fourteen age- and sex-matched healthy subjects were the controls. As expected, significantly higher levels of
6-sulphatoxymelatonin were present in nocturnal urine than in day-time urine in controls, while in both
cluster headache groups urinary levels of this metabolite did not differ between day and night. Nocturnal levels of
6-sulphatoxymelatonin were significantly lower in both
cluster headache groups than controls. Day-time levels did not differ significantly between the groups. Altered excretion of urinary
6-sulphatoxymelatonin even during remission indicates that at least some of these anomalies are independent of the
pain, and provides further evidence of involvement of the hypothalamic rhythm regulating centers in
cluster headache.