PERIPHERAL AUTONOMIC POTENTIALS IN PRIMARY HEADACHE AND DRUG-INDUCED HEADACHE

Autonomic functions of different primary headache types have been inve stigated in several studies, most of them analyzing cardiovascular ref lex mechanisms or biochemical changes. The results are contradictory; only in tension-type headache and in cluster headache has a sympatheti c hypofunction been shown in a preponderance of studies. We analyzed t he peripheral autonomous potentials (PAPs) in different primary headac he types and in drug-induced headache and compared the results with th ose of healthy subjects and of patients with low back pain. Latencies of PAPs were significantly increased in all headache types bat not in low back pain; amplitudes of PAPs did not show significant differences compared to healthy subjects. Patients with a long duration of drug a buse had increased PAP latencies, whereas patients with a high number of migraine attacks per year had decreased latencies. Our data suggest that sympathetic hypofunction as measured by PAP latencies is a gener al phenomenon in headache but not in all pain syndromes. Drug abuse le ads to an increase of this hypofunction. While measuring PAPs is not a n appropriate method by which to differentiate between headache disord ers, it allows assessment of autonomic disturbances in primary and dru g-induced headache.