The sensory nerve conduction study was performed by the antidromic recordings of evoked action potentials in human median nerve.

The 23 subjects employed in this study were confirmed neurologically healthy. Local ischemia was induced by use of pressure cuff, with which 200~250 mmHg pressure was applied on the subject arm for 25 minutes.

The subjects were divided into two groups:

GroupⅠ (18 subjects): compensatory group for the decreased skin temperature due to local ischemia with infra-red lamp. GroupⅡ (5 subjects): not compensatory group.

The results obtaining were as follows;

1) During ischemia, the conduction velocities of both distal and proximal segments slowed down progressively in both groups.

2) The decrease in amplitude and the increase in duration of sensory evoked action potentials were noted in both groups.

3) The degree of decrease in the sensory conduction velocity of proximal segment during ischemia was rather larger than that of distal segment in both groups.

4) The progressive slowing in conduction velocities, the decrease in amplitude and the increase in duration of action potentials were not statistically different in both groups.

These results suggest that local ischemia induces the progressive slowing of conduction velocity and results in the complete blocking of evoked action potential, but the secondary cooling due to ischemia could not affect significantly the changes in sensory conduction.