F-3-07-04
Diagnostic Value of Turns-amplitude Analysis in Neuromuscular Disease
Masanori Hamada, Hiroaki Nagashima, Hajime Inoue (Okayama University, Okayama, Japan)
Abstract: We presented a new method of turns-amplitude analysis of EMG interference patterns, modified from the original Stalberg's method. Ten samples were obtained from one muscle at maximum effort of voluntary contraction. As indices of amplitude (A), the average of the 3 highest and 3 lowest values out of the 10 samples were calculated. Similar indices were calculated for turns (T) and the T/A ratio. A total of 6 indices were evaluated. Criteria for the abnormalities in these 6 indices were determined through 25 normal volunteers. The test-retest reliabilities of the 6 indices were confirmed in the extensor digitorum communis muscle, and the Pearson product-moment correlation coefficients ranged from 0.907 to 0.767 (p<0.01). The clinical usefulness of this method was evaluated using patients with mild or moderate neuromuscular disorders. Two out of the 3 criteria were found to be abnormal in about 80% of those patients.
F-3-07-05
ELECTROPHYSIOLOGIC CILANGES BY LOW FREQUENCY STIMUULATION OF TIBIAL NERVE IN PERIPHERAL POLYNEUROPATHIC PATIENTS
Soo Jung Han, M.D., Chung Ki Lee, M.D.(Dept. of Rehab. Med., Ewha University, Seoul, Korea)
Electrical stimulation of the nerve has been reported to cause changes of the anterior horn cell excitability and the conduction of the nervous system in vivo and in vitro. Purpose of this study is to observe the neurophysiologic changes caused by 10 Hz electrical stimulation of polyneuropathic peripheral nerve. Subjects were 18 diabetic polyneuropathic patients diagnosed by the conduction studies. Four kinds of electrophysiologic studies were performed in the right (conditioned) and the left (unconditioned) tibial nerves before and after conditioning stimulation of the right tibial nerve. Electrophysiologic studies were the tibial motor and sensory conduction (Abductor hallucis), F response (Abductor hallucis), H reflex (Gastrosoleus) and somatosensory evoked potential (ankle, SEP). 10 Hz rectangular electrical current was used as the conditioning stimulation. It was applied to the popliteal tibial nerve in tolerable maximal intensity (10-24 mA) for 5 minutes.
Following changes were significant in statistics after conditioning. Prolongation of F latency (<.01), increases of F chronodispersion, duration and area (<.01), prolongation of H latency (<.01), increase of H amplitude (<.05), decrease of P1 latency of SEP (<.01) and increase of P1N1 amplitude of SEP (<.01) are seen in both conditioned and unconditioned legs. Increase of F wave conduction time and decrease of F wave conduction velocity (<.01) are seen in conditioned leg.
Above findings suggest that certain electrical stimulation of polyneuropathic nerve may cause increase of the anterior horn cell excitability, fascilitation of the SEP conduction and slowness of alpha motor conduction to and from spinal cord.
