Diagnostic potential of high resolution ultrasound and nerve conduction study in patients with idiopathic carpal tunnel syndrome

• Published in: Egyptian rheumatologist Vol. 41; no. 1; pp. 71 - 75
• Main Authors: El-Shintenawy, Aya A., Kassem, Elham M., El-Saadany, Hanan M., Alashkar, Doaa S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2019
• Subjects: Carpal tunnel syndrome; High resolution ultrasound; Median nerve; Nerve conduction study; Nerve conduction study; Carpal tunnel syndrome; High resolution ultrasound; Median nerve
• ISSN: 1110-1164; 2090-2433
• DOI: 10.1016/j.ejr.2018.04.001

To evaluate the diagnostic utility of high resolution ultrasound in comparison to nerve conduction study (NCS) in patients with idiopathic carpal tunnel syndrome (CTS). 40 patients with CTS (56 hands) and 30 matched controls (30 hands) were included. Patients and controls were assessed by clinical examination, ultrasonographic parameters including cross sectional area (CSA), flattening ratio 1 (FR1) at pisiform and FR2 at hamate and NCS including distal motor latency (DML), motor (MCV) and sensory (SCV) conduction velocity, sensory latency and amplitude. The mean age of the patients was 36.02 ± 8.4 years; 39 females and 1 males. This study included 37 right (92.5%) and 3 left-handed (7.5%) patients. Right-hand affection was detected in 17 (42.5%) patients, left-hand in 3 (7.5%) while bilateral hands affection was detected in 20 (50%). CSA and FR2 were significantly associated with CTS severity. CSA significantly correlated with all electrophysiological parameters including DML, sensory amplitude, sensory latency and SCV. FR1 significantly correlated with sensory latency and FR2 with SCV. Regarding sensitivity of ultrasonographic parameters, FR2 was the highest (91.3%) while CSA and FR1 were 80.3% and 50% respectively. Specificity of all ultrasonographic parameters was 100% and the highest sensitivity was for SCV (94.6%). There was an insignificant difference between nerve conduction study and high resolution ultrasound in diagnosis of idiopathic CTS. However, high resolution ultrasound had a superior diagnostic utility in CTS, and is valuable for exclusion of secondary CTS and anatomical variants of the median nerve.