Early detection of median nerve syndrome at the carpal tunnel with high-resolution 18 MHz ultrasonography in systemic sclerosis patients.

Objectives. To investigate carpal tunnel syndrome (CTS) with ultrasound (US) in asymptomatic SSc patients and to seek out the relationship between CTS and SSc clinical variables Methods. In 64 SSc patients (55 women and 9 men, mean age 57±14 years) and in 30 healthy controls, area (MNA), transverse (MNT) and anteroposterior (MNAP) diameters of MN at carpal tunnel were studied with US (My Lab 25 XVG US Esaote 18 MHz). MN flattening ratio (MNFR) was calculated. Duration of disease, subset (limited, diffuse), phase of skin involvement (oedematous, atrophic, fibrotic), modified Rodnan skin score (mRSS) and friction tendon rub were also recorded. Results. MNA (p<0.001), MNT (p<0.005) and MNFR (p<0.005) were significantly higher in the SSc patients than in controls, while no difference in MNAP was found. There was no correlation between median nerve (MN) and SSc clinical features (only lower MNAP correlated inversely with longer disease duration; Spearman coefficient -0.2). Conclusion. MN involvement is frequently present in all phases of asymptomatic SSc patients, independently to clinical variables.