Exteroceptive suppression of the masseter, temporalis and trapezius muscles produced by mental nerve stimulation in patients with chronic headaches.

Exteroceptive suppression of the masseter, temporalis and trapezius muscles, produced by mental nerve stimulation, was studied in 46 patients with chronic headaches. The background contracting electromyographic activity prior to stimulation showed no difference between normal subjects and patients with any type of headache. In patients with chronic tension-type headache associated with a disorder of the pericranial muscles, the duration and degree of exteroceptive suppression were lower when compared with normal subjects. A low degree of exteroceptive suppression was observed also in patients suffering from migraine without aura, although exteroceptive suppression in patients suffering from migraine with aura and cluster headache was the same as that in normal subjects. A low degree of exteroceptive suppression may play a role not only in chronic tension-type headache associated with a disorder of the pericranial muscles, but also in migraine without aura.