Endocrinology of cluster headache: potential for therapeutic manipulation.

Cluster headaches have always been among the most intriguing of the commonly recognized primary headache syndromes. This clinical interest is related to a number of factors, including the intense but short-lived nature of the pain, its sexual predilection, associated trigeminal autonomic dysfunction, and the remarkable circadian and circannual periodicity of cluster periods. Recent advances in neuroimaging and neuroendocrinology have shed light on the pivotal role of the hypothalamus in the biology of cluster headache. We discuss these revelations, along with current clinical observations in headache and sleep medicine.