[Changes of testosterone levels in the cluster headache syndrome. Preliminary study].

In a preliminary study, plasma testosterone values were obtained by the RIA method from 2 groups of cluster headache males at separate laboratories. Within each group the mean testosterone levels were compared between normal control and cluster patients in active and remission periods. Significantly lower values were consistently obtained from the active cluster patients when compared to either cluster-remission or normal control. The results of this preliminary study are interpreted as revealing a possible association of lowered plasma testosterone levels with the active cluster period in cluster headache syndrome.