To the Editor.—
I was very interested in Chokroverty and Medina's article, "Electrophysiological Study of Hemiplegia," in the Archives (35:360-363, 1978). However, in a previous study by my colleagues and I1 of a small group of hemiplegic patients, brachial plexus latencies were determined.Contrary to the findings in Chokroverty and Medina's study, our earlier investigation showed no abnormal brachial plexus latencies. We concluded that the brachial plexus injuries lay proximal to Erb's point in the upper trunk. Could the abnormal latencies reported in Chokroverty and Medina's study be compatible with the generally decreased skin temperatures that were recorded in the hemiplegic side? If temperature was thought to be a factor, would not intramuscular thermocouple electrodes be more appropriate?In this last case, the cold or hemiplegic side could be monitored by intramuscular thermocouple electrodes and then warmed up to an acceptable temperature prior to the determination of brachial plexus