Thomas Torres-Cuenca*, Fernando Ortiz-Corredor, Jorge Diaz-Ruiz, Diego Orozco-Salomon and Andrés Naranjo-Quevedo
Background: Ultrasonography is a diagnostic resource that serves as a complement in the evaluation of patients with carpal tunnel syndrome. The correlation of ultrasonography findings with nerve conduction studies can serve to classify new phenotypes and to evaluate therapeutic responses.
Objectives: To determine the diagnostic sensitivity of ultrasound, the correlation between the cross-sectional area against the motor and sensitive latencies, and the capacity to differentiate the mild, moderate and severe degrees of the electrophysiological classification of carpal tunnel syndrome.
Methods : A cross-sectional study with prospective data collection was carried out. An ultrasonography system with a 15 MHz transducer was used. Nerve conduction studies of the median nerve were performed with conventional techniques. Data from the most symptomatic hand were used. Determination of the correlations of nerve diameter with motor and sensitive latencies of the median nerve was performed in four age groups: 40 (n=11), 40-54 (n=47), 55-70 (n=42) y >70 (n=27).
Results A total of 127 patients were evaluated (average age = 58.2 years: minimum = 26; maximum = 85; SD = 13.4); female patients 109 (85.8%). According to the electrophysiological classification, mild = 40 (31.5%) were found; moderate = 60 (47.2%); and severe = 27 (21.3%). Significant differences in the area of the median nerve were found between the electrophysiological types (mild, moderate and severe; p = 0.000). The diagnostic sensitivity of ultrasonography differed for each age group. The capacity for ultrasonography to classify the degrees of electrophysiological severity was different for each age group.
Conclusions: There is a well-defined and significant correlation between nerve conduction studies and median nerve diameter in patients with Carpal Tunnel Syndrome. However, the exclusive use of the ultrasonographic measurement of the cross sectional area would not be enough to confirm or rule out an entrapment of the median nerve through the carpal tunnel, nor to predict in every case their electrophysiological severity.
Aged, Carpal Tunnel Syndrome, Diagnostic Ultrasound, Median Nerve, Nerve conduction studies, Ultrasonography
National University of Colombia, Department of Physical Medicine and Rehabilitation, Specialists Central of Colombia (CEC) Ibague, Colombia, National University of Colombia, Department of Physical Medicine and Rehabilitation, National University of Colombia, Department of Physical Medicine and Rehabilitation, Physiatry and Electrodiagnosis Research Center (CIFEL)