[Correlation between motor terminal latency time of the median nerve and the result of conservative treatment (cortisone injection) in carpal tunnel syndrome].

45 patients with carpal tunnel syndrome could be followed after an initial conservative treatment (local injection with Depomedrol 40 mg) either up to a surgical intervention (15 patients) or up to 14 to 48 months after the first injection (mean 23 months). Pregnant patients were excluded, as well as the patients with a distal motor latency (DML) greater than or equal to 7 msec (immediate surgical intervention). The age and sex distribution corresponds with the data reported in the literature: 7 males (15%) versus 38 females (85%), including 7 between 20 and 39 years (16%), 24 between 40 en 59 years (53%) and 14 between 60 and 80 years (31%). The side of the complaints also corresponds with the literature data: bilateral 16 (36%), right hand 23 (51%), left hand 6 (13%). In the 16 patients with a DML greater than 5,5 msec (normal value up to 4.3 msec) a rapid recurrence of the complaints after the injections necessitated a surgical intervention in 12 cases. In the 29 patients with a DML less than or equal to 5.5 msec who had been operated, the improvement of the complaints after the first injection lasted 2 months at most in 8 cases, as opposed to an average of 12.5 months (0 to 48 months) for the population as a whole.