Reduction of temporalis exteroceptive suppression by peripheral electrical stimulation in migraine and tension-type headaches.
Inhibition of the second exteroceptive suppression of temporalis muscle activity (ES2) produced by a preceding electrical stimulus applied at the index was studied in patients suffering from migraine without aura (MO), chronic (CTH) or episodic (ETH) tension-type headache. Each patient group comprised of 12 subjects was compared to a group of healthy controls. Mean duration of unconditioned ES2, measured on 10 averaged rectified responses after labial stimulation at a 0.1 Hz frequency, was reduced in CTH only. From stimulation intensities of 20 mA onward, peripheral-induced inhibition of temporalis ES2 was significantly more pronounced in both subtypes of tension-type headache compared to migraineurs or controls. After an index finger stimulus of 20 mA, temporalis ES2 was abolished in 83% of CTH, 67% of ETH, 25% of MO patients and 8% of controls, whereas unconditioned ES2 was present in all patients. Among 9 ETH patients with normal (> or = 32 msec) unconditioned ES2, 5 had total disappearance of ES2 after a 20 mA index stimulation. These results demonstrate that peripheral conditioning at 20 mA increases the diagnostic sensitivity of ES2 studies. They suggest that the changes observed in tension-type headache are due to hyperexcitability of the reticular nuclei which inhibit the medullary inhibitory interneurons mediating ES2.
Wei
Wang
W
Department of Neurology, Unirersity of Liège, CHR Citadelle, B-4000 LiégeBelgium.
Schoenen
Jean
J
D000328:Adult; D002908:Chronic Disease; D003213:Conditioning, Psychological / Q000502:physiology; D004599:Electric Stimulation Therapy; D004576:Electromyography; D005260:Female; D005385:Fingers / Q000502:physiology; D006801:Humans; D008046:Lip / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D010525:Peripheral Nerves / Q000503:physiopathology*; D018781:Tension-Type Headache / Q000503:physiopathology*