Hormonal (dys)function in cluster headache

Cluster headache is a very severe primary headache disorder for which the cause
remains unknown. Interestingly, cluster headache attacks often appear at night,
one hour after falling asleep, suggesting a link with sleep and the biological
clock, residing in the suprachiasmatic nucleus of the hypothalamus. Melatonin
is produced in the suprachiasmatic nucleus and is closely related to the
sleep-wake cycle and the circadian rhythm. Previous studies indicate a lower
melatonin production in cluster headache patients. Cluster headache was always
considered a *male* disease, although male:female ratio appears to be
declining, most likely due to better diagnosis amongst woman. Despite this
declining ratio, males are still heavily overrepresented in cluster headache
with an estimated male:female ratio of 2:1. Surprisingly, several small scale
studies reported lower testosterone levels in male cluster headache patients.

We hypothesize that hormone levels in chronic cluster headache patients will be
the most severe affected compared to episodic cluster headache patients and
healthy controls.

To compare free testosterone levels between male CCH patients and healthy
controls

Secondary Objectives:
To compare differences in androstenedione, DHEA, DHT and 11oxC19 level,
testosterone/estrogen ratio, activin level, inhibin level and morning cortisol
level in blood and 6-sulfatoxymelatonin level in nocturnal urine between:
- All cluster headache groups (ECH patients in bout, ECH patients out of bout
and CCH patients)
- All ECH patients (in an episode and outside an episode) versus healthy
controls

Cross-sectional with a longitudinal aspect in episodic cluster headache
patients.

The burden and risks associated with this study are very low. Only one
container of blood will be taken through a single vena punction. Episodic
cluster headache patients will be tested twice: inside and outside the cluster
bout. Furthermore, participants are instructed to collect overnight urine one
night.