Nostril capsaicin application as a model of trigeminal primary sensory neuronal activation

Capsaicin was applied unilaterally to the nostril mucosa of 18 episodic cluster headache sufferers in remission. Plasma and saliva levels of substance P (SP), calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) were measured by radioimmunoassay. Increase of salivary SP-LI and CGRP-LI as well as of plasma CGRP-LI occurred after capsaicin stimulation. Capsaicin-induced neurochemical changes in saliva and in plasma were compared to the changes observed during cluster headache attacks measured in a separate study. The comparative changes in SP, CGRP and VIP characterizing these two conditions suggest that trigeminal capsaicin-sensitive sensory neurones are unlikely to play any fundamental role in the mechanics of cluster headache.

Immunological alterations in cluster headache during remission and cluster period. Comparison with low back pain patients

Cluster headache is a disorder of unknown origin. Some studies have focused their attention on neuroendocrine derangement, others on immunity. To probe central alterations in cluster headache (CH), immune parameters were investigated in cluster headache patients in comparison to low back pain patients and healthy controls. Increases in peripheral blood monocytes found in remission cluster headache patients may be attributable to chronic central nervous system (hypothalamic?) noradrenergic dysfunction or altered beta-endorphin. Alterations in NK+, CD3+ and CD4+ levels found in cluster period cluster headache and low back pain patients are probably pain or stress-related.