Ultrasonography of Median Nerve in Carpal Tunnel Syndrome in Patients with Hypothyroidism

ABSTRACT

Carpal tunnel syndrome (CTS) is a common peripheral entrapment neuropathy in patients with hypothyroid. The diagnosis of CTS is usually clinical and confirmed by electrodiagnostic procedures. This study aimed to describe the diagnostic accuracy of high-resolution ultrasonography (US) as an alternative method to nerve conduction study for the diagnosis of subclinical CTS in patients with hypothyroidism before and after hormone replacement therapy. Methods: Sixty patients diagnosed with hypothyroidism were included in this study. Electrodiagnostic workup and ultrasonographic assessment of both right and left median nerves were done at the initial time of diagnosis and 3 months of euthyroid state after hormone replacement. Results: The comparison between right and left median nerves motor and sensory functions before and after treatment showed a significant change (P < 0.001). Right median nerve distal and proximal CSA were 13.5±1.4 mm2 and 10.6±1.5 mm2 respectively. On the left side CSA values were 13.1±2.1 mm2 and 9.9±0.5 mm2 respectively. After hormone replacement, values changed to 11.0±1.4 mm2 (distal) and 0.086±.003 mm2 (proximal) on the right side and 11.0±1.6 mm2 (distal) and 8.2±.0.4 mm2 (proximal) on the left side. 40 patients showed significant electrophysiological and radiological improvement with hormonal control. Conclusions: The US for median nerve cross sectional area can be used as a noninvasive diagnostic method which may be used for prognostication of CTS.