Email updates

Keep up to date with the latest news and content from BMC Neurology and BioMed Central.

Open Access Research article

The diagnostic value of ultrasonography in carpal tunnel syndrome: a comparison between diabetic and non-diabetic patients

Nai-Wen Tsai1, Lian-Hui Lee1, Chi-Ren Huang1, Wen-Neng Chang1, Hung-Chen Wang2, Yu-Jun Lin23, Wei-Che Lin4, Tsu-Kung Lin1, Ben-Chung Cheng35, Yu-Jih Su5, Chia-Te Kung6, Shu-Fang Chen13* and Cheng-Hsien Lu13*

Author Affiliations

1 Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan

2 Department of Neurosurgery, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan

3 Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan

4 Department of Radiology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan

5 Department of Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan

6 Department of Emergency Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan

For all author emails, please log on.

BMC Neurology 2013, 13:65  doi:10.1186/1471-2377-13-65

Published: 24 June 2013

Abstract

Background

To compare the value of ultrasonography for diagnosing carpal tunnel syndrome (CTS) in patients with and without diabetes mellitus (DM).

Methods

Eighty non-DM and 40 DM patients with electromyography-confirmed CTS were assessed and underwent high-resolution ultrasonography of the wrists. Cross-sectional area (CSA) and flattening ratio (FR) of the median nerve were measured at the carpal tunnel outlet (D) and wrist crease (W).

Results

The 80 non-DM and 40 DM patients had 81 and 59 CTS-hands, respectively. The CSA_D and CSA_W were significantly larger in the CTS-hands and DM-CTS-hands compared to the normal control (p < 0.001). However, there is no difference of CSA_D and CSA_W between DM and non-DM CTS patients. Receiver operating characteristics [ROC] curve analysis revealed that CSA_W ≥13 mm2 was the most powerful predictor of CTS in DM (area under curve [AUC] = 0.72; sensitivity 72.9%, specificity 61.9%) and non-DM (AUC = 0.72; sensitivity 78.5%, specificity 53.2%) patients. The CSA positively correlated with the distal motor latency of the median compound motor action potential (CMAP), distal sensory latency of the median sensory nerve action potential (SNAP), and latency of the median F wave, but negatively correlated with the amplitude of the median CMAP, amplitude of the median SNAP, and sensory NCV of the median nerve. Stepwise logistic regression revealed that CSA_W (OR 1.21, 95% CI 1.07-1.38; p = 0.003) was independently associated with CTS in DM patients and any 1 mm2 increase in CSA_W increased the rate of CTS by 28%.

Conclusions

The CSA of the median nerve at the outlet and wrist crease are significantly larger in CTS hands in both DM and non-DM patients compared to normal hands. The CSA of the median nerve by ultrasonography may be a diagnostic tool for evaluating CTS in DM and non-DM patients.

Keywords:
Carpal tunnel syndrome; Cross-sectional area; Median nerve; Ultrasonography