Evaluation of interictal autonomic function during attack and remission periods in cluster headaches.

OBJECTIVE: To investigate which part of the autonomic system is mainly involved and assess the sensitivity of face sympathetic skin response in cluster headache.
MATERIAL AND METHODS: The study sample consisted of 19 drug-free cluster headache patients (16 males, three females) and 19 healthy volunteers. Demographic features and pain characteristics were thoroughly identified. Dysautonomic symptoms were evaluated during attack and remission periods of cluster headache patients. Orthostatic hypotension, R-R interval variation and sympathetic skin responses obtained from the face and four extremities were evaluated and the sensitivity of face sympathetic skin responses was assessed in contrast to extremity sympathetic skin responses.
RESULTS: All sympathetic skin responses of face and extremities could be obtained during attack and remission periods. On the symptomatic side, mean latency of face sympathetic skin responses was longer compared to the asymptomatic side and controls (p = 0.02, p = 0.004). There were no differences in latency or amplitude of extremity sympathetic skin responses between symptomatic and asymptomatic sides and controls. No significant relationship was determined between sympathetic skin responses, R-R interval variation, orthostatic hypotension and cluster headache clinical features.
CONCLUSION: Sympathetic hypoactivity of the face seems to predominate the pathophysiology of cluster headache. Face sympathetic skin responses might be more sensitive compared to extremity sympathetic skin response in demonstrating dysautonomic symptoms in cluster headache patients. © International Headache Society 2015.