Median neuropathy at the wrist(Carpal tunnel syndrome) is one of the most common entrapment neuropathy. An electrodiagnostic study has been widely used as a tool for a diagnosis of carpal tunnel syndrome. Recently, Ernest W. Johnson has studied
median
and radial sensory distal latencices to digit 1 for a carpal tunnel syndrome as a diagnostic method.
We applied this method to 50 normal healthy persons and 13 carpal tunnel syndromes.
@ES The results were summarized follows:
@EN 1. In the normal control group hands, the mean sensory distal latencies and radial nerve were 2.69±0.26msec, 24.96±6.26uV, 2.44±0.23msec, 15.41±3.98uV respectively.
2. The difference in latencies of median and radial nerve were 0.69msec or less(95%) in normal subjects and 1.18msec in carpal tunnel syndrome.
3. Recording sensory conduction in thumb seems valuable in the diagnostic method of carpal tunnel syndrome.
4. There was no difference in latencies of median nerve between age and sex, while the amplitude of the median nerve showed some difference between age and sex.
5. The difference in latencies of median and radial nerves was 0.6msec or less(95%) in normal subjects. According to the above results, the validity tests showed 93.3% in sensitivity and 95.9% in specificity.
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