Electromyographical Studies on Activity of Spinal Motorneurone (about Rigidity and Tremor) Part 1. Excitability of the spinal motorneurone for tremor and clonus

Electromyographical studies on the calf muscles following stimulation to the posterior tibial nerve at popliteal fossa were carried out on the patients with parkinsonian tremor or with ankle clonus. Grouping discharges of both parkinsonian tremor and clonus of the calf muscles were suspended for a certain period followed by the same grouping discharge as before the shock when a shock was given to the nerve to provoke the monosynaptic H-reflex response on the calf muscles. The recovery curves of the H reflex responses following each grouping discharge in both tremor and clonus tested were compared. These curves indicate that the excitabilty of the motorneurones is within normal limit in the parkinsonian tremor while it is exagger ated in clonus, when correlated with the results described by Magladery and his coworkers.