[EMG analysis of exteroceptive suppression of temporal muscle activity in tension headache]

In modification of a method published by Schoenen et al., early (ES 1) and late (ES 2) exteroceptive suppression periods elicited by perioral electrical trigeminus-stimulation during teeth-clenching were recorded with surface electrodes over the temporalis muscles. 29 patients with chronic tension headache, 20 with migraine, 7 patients with combined tension headache and migraine and 19 controls were examined. Duration of the late suppression period for the mean of three single shocks was highly significantly reduced in chronic tension headache sufferers and patients with combined tension headache and migraine when compared with migraine cases or controls. These results are in agreement with those of Schoenen et al. EMG analysis of temporalis late exteroceptive suppression is a helpful diagnostic method in primary headache. The reduction of ES 2 in chronic tension headache sufferers might suggest a deficient activation or excessive inhibition of the motoric trigeminus nucleus by pontobulbar inhibitory neurons which receive a strong input from limbic and nociceptive structures.