Plasma melatonin pattern in chronic and episodic headaches: evaluation during sleep and waking.

To look for a relationship between pineal function in chronic migraine (CM), cluster headache (CH) (during active and remission periods), chronic tension-type headache (CTTH) patients and controls during NREM sleep, REM sleep and waking, we performed serial sampling of plasma melatonin in the different sleep stages during the first half of the night, in order to avoid chronobiological interferences. Plasma melatonin levels did not show a normal curve either in the CTTH or in the CM patients and no significant differences between these groups were found in any of the sleep stages studied. Plasma melatonin values of CH patients during the cluster period showed an abnormal pattern. The curve showed a pathological lack of peaks during the active period, melatonin levels remaining within normal daytime range throughout the study. A trend to normalization of the curve during the remission period was observed. On the basis of these different melatonin secretion patterns, it might be hypothesized that the involvement of the hypothalamus in chronic-type headaches differs from that displayed in episodic forms.