[Clinical and electrophysiological correlations concerning patients with carpal tunnel syndrome].

Background: Carpal tunnel syndrome (CTS) is the most commonly diagnosed nerve entrapment neuropathy. Typical clinical symptoms are pain, paresthesia or sensory deficit in the median nerve. In more severe cases the weakness and atrophy of the thenar muscles are also diagnosed. It is believed that the clinical picture along with the electrophysiological test allows making the diagnosis. However, the findings of the studies assessing the clinical and electrophysiological correlations are quite different.

Aim Of The Study: The aim of this study was to establish the correlations between the assessment of a neurological examination and selected parameters of standard electrophysiological tests.

Material And Methods: In the study of 172 patients (253 nerves) with clinical symptoms of CTS, there were 131 women and 41 men at the age of 19-84 (the average: 51.28 +/- 17 years). All the patients underwent standard electrophysiological tests, according to the guidelines of the American Academy of Neurology, the test assessing the sensory latency at the wrist to the second finger (SL-D2) and the test assessing the motor latency at the wrist to the abductor pollicis brevis (DML-APB) and additional D4M-D4U test.

Results: In the neurological examination the most common findings were the sensory deficits in the median nerve (87%) and the weakness of the thenar muscles (71%). Less common was the atrophy of the thenar muscles (25%). Abnormal results, leading to the electrophysiological diagnosis of CTS, were shown in 194 cases (77%) under the SL-D2 test and in 170 cases (67%) under the DML-APB test. Abnormal D4M-D4U test result was found in 94% of patients. In the group of patients we established a statistically valid correlation between the sensory deficit and the results of the SL-D2 test as well as between the weakness of the thenar muscles and the results of the DML-APB test, which indicates the diagnostic value of these parameters.

Conclusions: The discrepsancies lie in the different criteria for the selection of patients, the statistical methods applied, the selection of clinical scales as well as neurophysiologic testS.