Study of the ulnar nerve compromise at the wrist of patients with carpal tunnel syndrome.

INTRODUCTION: That the ulnar nerve compromise occurs concomitant with the carpal tunnel syndrome (CTS) has been cited by previous studies. It seems that the previously mentioned incidence is much higher than what we observe in our electrodiagnosis studies.

MATERIAL AND METHOD: A prospective study was designed to evaluate the incidence of ulnar nerve compromise in patients with electrodiagnostic evidence of CTS according to age and sex, and also to determine the site of ulnar nerve involvement.

RESULTS: One hundred and sixty five limbs with standard elestrodiagnostic criteria of CTS were evaluated In 9.7% of the tested limbs, the ulnar nerve was involved. The site of the involvement was the wrist area in 43.75%. The elbow region was involved in 43.75%, and in 12.5%, the forearm region was involved. The most prevalent age range of concomitant involvement was 45-54 years old. In patents who had sensory symptoms in the 4th and 5th fingers, the incidence of concomitant ulnar nerve compromise was significantly higher (p < 0.001) than the patients without these symptoms.

DISCUSSION: In patients with CTS, concomitant ulnar nerve compromise is much lower than the incidence mentioned in previous researches. Apparently the rate of involvement in wrist and elbow are equal. It is recommended that in evaluation of patients for CTS especially when the patient has sensory symptoms in the hand, special attention is paid to ulnar nerve involvement and two nerve comparison tests are interpreted with caution.