10 April 2026 : Review article
Carpal Tunnel Syndrome Diagnosis: A Narrative Review of Complementary Roles of Neuromuscular Ultrasound and Electrodiagnostic Studies
Yumeng Dong AEF 1, Yunrui Zhuang AEF 2*, Lingmei Li BDF 2, Yanduo Li BC 2, Huiyan Dai DF 3DOI: 10.12659/MSM.952034
Med Sci Monit 2026; 32:e952034
Table 1 Summary of median nerve cross-sectional area (MN-CSA) thresholds and diagnostic performance across selected studies.
| Study (year) | Population | Measurement site | Threshold (mm2) | Sensitivity (%) | Specificity (%) | AUC | Key notes |
|---|---|---|---|---|---|---|---|
| Abd El Maged et al (2024) []78 | General (Egyptian) | Carpal tunnel inlet | 8.8 | 97.1 | 85.7 | 0.971 | Proposed inlet & outlet cutoffs; strong CSA–NCS correlations |
| Abd El Maged et al (2024) []79 | General (Egyptian) | Carpal tunnel outlet | 8.4 | 88.6 | 51.4 | 0.896 | Lower specificity at outlet vs inlet |
| Braham et al (2024) []32 | Occupational CTS (workers) | Carpal tunnel inlet | 10.3 | 89.0 | 84.0 | – | CSA correlated with EMG; assoc. with symptom duration |
| Sertbaş et al (2023) []43 | Type 2 diabetes | Carpal tunnel inlet | 10.0 | 83.33 | 41.9 | 0.674 | CSA & DM duration predicted CTS presence |
| Sertbaş et al (2023) [] (severe CTS)43 | Type 2 diabetes | Carpal tunnel inlet | 13.0 | 88.89 | 80.67 | – | Threshold predicting severe CTS |
| Klauser et al (2009) []17 | General | Max CSA in carpal tunnel | 12.0 | 94.0 | 95.0 | – | ΔCSA ≥2.0 mm → sens 99%, spec 100% |
| Hunderfund et al (2011) []31 | General | Carpal tunnel inlet | 11.0 | 84.0 | 84.0 | – | Wrist–forearm ratio 2.4 → sens 67%, spec 86% |
| Roll et al (2011) []18 | General | Pisiform (inlet region) | 10.3 | 80.4 | 90.6 | – | Also reported WFR threshold 1.7 (80%/81%) |
| Kang et al (2012) []31 | General | Carpal tunnel inlet | 9.5 | 96.4 | 92.1 | – | Severe CTS cutoff 14.15 mm (69.4%/68.7%) |
| Fowler et al (2011) []19 | General | Carpal tunnel inlet | 10.0 | 89.0 | 90.0 | – | Validated clinical tool as reference |
| Gupta et al (2024) []36 | General | Distal wrist crease (inlet) | 10.0 | 78.85 | 82.14 | 0.860 | Delta CSA performed best overall; ROC suggested 9.5 mm improves CSAc |
| Yuan et al (2024) [] (elderly)79 | Elderly | Not specified | – | – | – | 0.683 | CSA AUC for mild/moderate CTS; correlations with DML and CMAP |
| AUC – area under the curve; CSA – cross-sectional area; CTS – carpal tunnel syndrome; DM – diabetes mellitus; EMG – electromyography; MN-CSA – median nerve cross-sectional area; NCS – nerve conduction studies; ROC – receiver operating characteristic; WFR – wrist-to-forearm ratio; ΔCSA – difference in CSA (carpal tunnel inlet minus distal forearm CSA). | |||||||