Electrodiagnosis of the carpal tunnel syndrome.

In the carpal tunnel syndrome median nerve motor conduction may be delayed below the wrist, while the motor nerve fibre conduction velocity above-the wrist may be relatively unaffected (Carpendale, 1956; Simpson, 1956). Median nerve sensory conduction may also be impaired below the wrist in the carpal tunnel syndrome (Gilliatt and Sears, 1958). No detailed study has been made comparing distal sensory and motor conduction in patients with the carpal tunnel syndrome. Such a comparison is important, since one mode of conduction may be affected before the other and knowledge ofthis would help to assess the best means of electrodiagnosis for the carpal tunnel syndrome as well as giving further insight into the condition.