Sensory testing in patients with hemodialysis-associated carpal tunnel syndrome submitted to surgical decompression

Carpal tunnel syndrome (CTS) is the most common compression neuropathy of the upper limb. Close to 5% of patients with chronic renal failure who need hemodialysis present CTS. Clinical history and physical examination remain the most adequate tools for diagnosis, and there is still controversy regarding the most reliable test to complement it. Evaluation of sensory thresholds using Pressure-Specified Sensory Device (PSSD) has become an important instrumental test.

This study aimed to determine the values of pressure sensory thresholds using the PSSD before and after treatment of CTS in a special group of patients who underwent chronic hemodialysis. The PSSD incorporates a pressure transducer linked to a computer capable of measuring the cutaneous pressure thresholds referred by the patient. Two groups were compared as follows: group 1, patients with hemodialysis-related CTS; and group 2, CTS in non-hemodialysis patients. The following measurements were assessed: static one point, moving one point, static two points, and moving two points.

There was improvement (lower thresholds) in the postoperative measurements in all parameters assessed in group 1, and improvements in all parameters except the moving one point test in group 2.

Nerve decompression, as expected, can be considered a good treatment of CTS even in more severe cases as in those patients under hemodialysis. The PSSD tests were reliable to confirm the diagnosis and thus to indicate the decompression. It is even more beneficial to provide a comparison between preoperative and postoperative data and different causes of CTS.