I will say very little about the source of cluster headache because so little is known. The best data available suggests that cluster headaches are somehow regulated by the posterior hypothalamic gray matter. This region of the brain is responsible for our circadian rhythms as well as biologic functions such as appetite and temperature regulation. It is felt that a defect in this region occurs in those patients who get cluster headaches and this is why they occur principally at night. The mechanism which triggers a series of cluster headaches and then stops a series of cluster headaches is unknown.

Treating Acute Cluster Headaches