A chronobiological study of melatonin, cortisol growth hormone and prolactin secretion in cluster headache.

The temporal organization of plasma melatonin, cortisol, growth hormone (GH) and prolactin secretion was examined in healthy rested controls and in patients suffering from episodic cluster headache. Eleven patients with typical cluster headache (10 men, 1 female) and 8 male controls were studied over a 24-h period: blood was collected at 2-h intervals during the day and at 1-h intervals at night. Plasma melatonin, cortisol, GH and prolactin levels were determined by radioimmunoassay. Most of the cluster headache patients showed a decrease in nocturnal melatonin secretion and the melatonin rhythm was even completely abolished in one patient. Chronobiological analysis of the cluster headache patients' 24-h plasma melatonin profile showed a significant decrease in amplitude and mesor: these were 58.7 pg/ml and 34.4 pg/ml respectively in control subjects, versus 18.7 pg/ml and 17.6 pg/ml for the patients. In addition, patients showed a significant phase-advance in their melatonin rhythm. For cortisol, the rhythm appeared slightly blunted in the cluster headache group and was significantly phase-advanced. The plasma prolactin profile showed no significant alteration, but for plasma GH the nocturnal peak was advanced in some patients; in the absence of sleep recording, however, no conclusion could be drawn. Results from this study suggest a neuroendocrine dysregulation in cluster headache in the endogenous clock which controls the pineal rhythmicity.