Cluster Headache- what is the pathophysiology?
The underlying pathophysiology of cluster headache (CH) is incompletely understood. The periodicity of the attacks suggests the involvement of a biologic clock within the hypothalamus (which controls circadian rhythms), with central disinhibition of the nociceptive and autonomic pathways—specifically, the trigeminal nociceptive pathways. Positron emission tomography (PET) and voxel-based morphometry have identified the posterior hypothalamic gray matter as the key area for the basic defect in CH.
@margie Early studies suggested that discography had a low specificity, but more recent studies have failed to induce pain in asymptomatic controls, suggesting that discography has utility in identifying patients with discogenic pain. Pain reproduction during discography in symptomatic individuals is variable, with a lower incidence of pain reproduction in patients with disk degeneration than in those with posterior tears of the anulus fibrosus or significant disk bulges.