Table 1. Study characters.
NR: not reported; CSA; cross-sectional areas; FR; flattening ratio; DML: distal motor latency; DSL: distal sensory latency; SCV: sensory conduction velocity; SNAP: sensory nerve action potentials; CMAP: compound muscle action potential; NCS: nerve conduction studies; NCV: nerve conduction velocity; EDX: electrodiagnostic tests
| Author ID | Study design | Subject characteristics (subjects/wrists) | Classification of diagnosis (n) | US measures (cut-off) | NCS or electromyography measures | Main outcomes |
| Kwon et al., 2008 [8] | A prospective, case-controlled study | 29/41 (4 males and 25 females, 53 (25–75) years) | NR | CSA (10.7 mm2) | Sensory amplitude. DML, DSL | Using a CSA cut-off point of 10.7mm2, the sensitivity and specificity of sonography and NCS were 66% and 63%, respectively. A combination of NCS and sonography gave sensitivity and specificity values of 90% and 62%, respectively. |
| El-Shintenawy et al., 2019 [14] | Cohort study | 40/56 (39 female and 1 male; 36.02 ± 8.4 years). | Negative (2), Minimal (2), Mild (28), Moderate (16), Severe (8) | CSA (>9 mm2) FR1 (>3) FR2 (>4) | DML, DSL, Sensory amplitude, SCV | The sensitivities for ultrasound parameters were (80.4%, 50%, and 91.3%, p<0.001 for CSA, FR1, and FR2, respectively). All the ultrasound parameters showed a specificity of 100%. The sensitivities for NCS parameters were 53.6, 55.4, 73.2, and 94.6% for DML, DSL, sensory amplitude, and SCV, respectively. The specificity was significantly higher in DML and SCV (100%, p<0.001) while it was significantly lower in sensory latency (63.3%, p=0.04). |
| Swen et al., 2001 [15] | Cohort study | 63 (44 women and 19 men; 52 ± 13 years) | NR | CSA (>10 mm2) | DSL, DML, SCV, MCV | NCS showed a significantly higher sensitivity than sonography (0.98 vs. 0.70, respectively). Sonography recorded a higher specificity than NCS (0.63 vs. 0.19). |
| El Miedany et al., 2004 [10] | Cross-sectional case-control study. | 78/96 (51 female and 27 males; 44.9 ± 6.16 years) | Negative (6), Mild (30), Moderate (33), Severe (27) | CSA (>10.03 mm2) | DSL, DML, SCV | 6 hands showed negative results on the electrophysiological tests while only 2 hands showed negative results upon Ultrasound assessment. Ultrasound assessment on patients with moderate and severe diagnoses resulted in a 96.6% sensitivity and 99% specificity. |
| Pimentel et al., 2018 [16] | Prospective clinical trial | 115 females (40 – 79 years) | NR | CSA (≥ 10 mm2) | SCV, DML | NCS showed higher sensitivity and specificity than ultrasound (92.3% and 90.9% vs. 84.6% and 81.8%, respectively) |
| Visser et al., 2007 [17] | Prospective cohort study | 168 (39 male and 129 females; 52 +- 14 years) | Normal (94), Mild (53), Moderate (8), Severe (12) | CSA (>0.1 cm2) | SNAP, DSL, DML, Distal CMAP, median nerve | 16 of 28 patients with negative EMG had a positive sonogram. The sensitivity and specificity for sonography were 78% and 91%, while EMG tests for DML median nerve > 3.8 msec showed a sensitivity and specificity of 74% and 97%, respectively. 1 patient had a slight preference for EMG while 5 patients had a very strong preference for sonography. |
| Filho et al., 2014 [6] | Cross-sectional study | 56/70 (2 males and 54 females) | NR | NR | NR | EMG had higher sensitivity than ultrasound and physical examination tests (98.6% vs. 67.1% vs. 95.7%, respectively). |
| El Badry et al., 2016 [18] | Prospective study | 100 (24 men and 76 women; mean age 41.3 years) | Normal, Mild, Moderate, Severe | NR | SCV, DML | NCV showed clinically 90 positive and 10 negative CTS cases while ultrasound showed 86 positive and 14 negative cases. The sensitivity and specificity of NCV and ultrasound were 90% and 79.2% vs. 86% and 77.4%, respectively. |
| Kele et al., 2003 [19] | Comparative study | 77/110 (59 women and 18 men; 52 (22 – 84) years). | NR | CSA (≥0.11 cm2) | SCV, DML | A higher predictive value of ultrasound was observed for CSA > 0.11 cm2 (89.1% and 98%, sensitivity and specificity, respectively. The electrophysiological test showed a sensitivity of 90.0%. |
| Azami et al., 2014 [20] | Prospective cross-sectional study | 90/120 (83 women and 7 men; 56.8 + 10.6 years) | Mild (57), Moderate (39), Severe (34) | CSA (9.15 and 8.15 mm2), FR (1.02, 1.01 and 0.94) | SCV, DML | CSA at the tunnel inlet with a threshold of 9.15 mm2 provided the best diagnostic accuracy with a sensitivity of 99.2% and specificity of 83.3%. The sensitivity and specificity of the ultrasonography at a 1.02 cut-off for the FR at the proximal were 98.3% and 46.7%, respectively. |
| Fowler et al., 2014 [21] | Comparative cohort study | 85 (31 men and 54 women; 56 (18 – 86) years) | NR | CSA (≥10 mm2) | DSL, DML | Using the EDX tests as the reference standard, ultrasound had a sensitivity of 85% and specificity of 83%. Electrodiagnostic tests showed sensitivity and specificity of 89% and 80%, respectively. |
| Moran et al., 2009 [22] | Prospective study | 46/70 (40 women and 6 men; 45 (30 – 80) years) | Negative (20), Mild (15), Moderate (13), Severe (22) | CSA (9.8, 12.30, 11, and 13 mm2) | DML | NCS confirmed CTS in 50 of 70 hands. The sensitivity and specificity for CSA >9.8, ≥12.30, >11 and >13 was 92% and 45% vs. 62.0% and 95% vs. 86% and 40% vs. 60% and 90.0%, respectively. |