[Carpal tunnel syndrome. Electrophysiologic aspects of the natural course and after treatment].

Fifty-eight cases of carpal tunnel syndrome confirmed by electromyography by combined studies of motor and sensory conduction of the median nerve at the wrist have been the subject of electrical studies to assess spontaneous changes and progress after treatment. Spontaneous progress in 9 cases showed an absence of changes in electromyographic findings in general and the possibility of definite improvement or rapid spontaneous worsening. Progress after local corticosteroid injections showed a statistically significant improvement after 1 to 2 months but they also showed an overall progressive return to the previous values in 6 to 12 months. Again, progress may be either clearly favourable or unfavourable. The injection seemed to alter the natural progress only very slightly. Only after operative treatment in 17 cases was there a very obvious and often rapid statistically significant improvement. This improvement was lasting and continued for at least up to a year.