Ultrasound Measurements of the Ulnar Nerve at the Medial Epicondyle Correlate With Electrodiagnostic Studies.

BACKGROUND: Cubital tunnel syndrome is the second most common compressive neuropathy in the upper extremity and is commonly evaluated with electrodiagnostic studies (EDS). Ultrasound (US) has emerged as a potentially more efficient alternative to EDS. The purpose of this study is to evaluate whether measurements of the cross-sectional area (CSA) of the ulnar nerve at the elbow correlate with EDS results. METHODS: This study was a prospective analysis of patients who presented with signs and symptoms consistent of cubital tunnel syndrome, who received USs of the ulnar nerve at the elbow and nerve conduction tests. Pearson correlation coefficients were used to evaluate the correlation between ulnar nerve CSA and electrodiagnostic data. t Tests were used to evaluate statistical differences between the mean ulnar nerve CSA of patients with positive or negative nerve conduction study results. Youden Index was used to calculate the optimal cut-off point for US CSA based on maximal sensitivity and specificity. Statistical significance was based on a two-sided P less than .05. RESULTS: The association between increasing US CSA at the medial epicondyle with slowing of the conduction velocity of the ulnar motor nerve across the elbow was statistically significant (r = -0.35, P = .02). Patients with positive EDS tests had significantly larger nerve size than those with negative tests (all Ps < .03). A cut-off point of greater than or equal to 11 mm2 had a sensitivity of 70.83% and specificity of 66.67%. CONCLUSIONS: Larger ulnar nerve CSAs correlate with slowing of the conduction velocity on EDSs, and those with positive EDSs have larger nerve sizes than those with negative tests.

Area Deprivation Index Is Not Associated With the Severity of Carpal Tunnel Syndrome.

BACKGROUND: While living in a socially disadvantaged neighborhood is linked with numerous health outcomes, its effect on patient-reported outcome scores and diagnostic measures in carpal tunnel syndrome (CTS) is not fully understood. This study examines the effect of neighborhood socioeconomic deprivation on CTS severity as measured by the Boston Carpal Tunnel Questionnaire (BCTQ), 6-item Carpal Tunnel Symptoms Scale (CTS-6), and diagnostic testing modalities. METHODS: This was a retrospective analysis of patients who presented to the hand clinic at a single hospital system with symptoms consistent with CTS. Ultrasound cross-sectional area (CSA) of the median nerve, CTS-6, Symptom Severity Scale (SSS) and Functional Status Scale (FSS) of the BCTQ, and the Area Deprivation Index (ADI) national rank percentile were collected. Patients were grouped into 4 quartiles based on their ADI national percentile. Analyses of variance (ANOVAs) were conducted to test for statistical differences between the 4 quartiles based on the average values of median nerve CSA, CTS-6, SSS, and FSS score. The bottom quartile was compared with the upper 75% of the sample (26th-100th percentile) and to the upper quartile via Student t test. Statistical significance was set at P < .05. RESULTS: Analyses of variance revealed no statistically significant differences between the 4 quartiles for either median nerve CSA, CTS-6, SSS, or FSS. When comparing the bottom quartile with the upper 75% of the sample and the upper quartile, no significant statistical differences were identified. CONCLUSIONS: No relationships were found between social deprivation (ADI) and patient-reported outcomes, CTS-6 scores, or median nerve CSA.

Ultrasound Measurements of the Median Nerve at the Distal Wrist Crease Correlate With Electrodiagnostic Studies.

Background: Carpal tunnel syndrome (CTS) is the most common nerve entrapment neuropathy and is commonly evaluated using electrodiagnostic studies (EDSs). Ultrasound (US) has emerged as a potentially easier and more comfortable alternative to EDSs. The purpose of this study is to evaluate whether measurements of the cross-sectional area (CSA) of the median nerve via US correlate with the severity rating of CTS based on EDSs. Methods: A retrospective review of patients aged 18 years or older who underwent US and EDSs of the median nerve for CTS was performed. Sensory nerve action potential, distal motor latency, and compound muscle action potential were measured, and severity was graded on American Association of Neuromuscular and Electrodiagnostic Medicine guidelines. Cross-sectional area of the median nerve was measured via US at the wrist crease. Results: There was a significant association between increasing CSA and increasing EDS severity (P < .0001). The mean CSA for normal, mild, moderate, and severe CTS was 7.48 ± 2.00, 10.36 ± 2.53, 12.01 ± 3.64, and 14.34 ± 4.77 mm2, respectively. The area under the curve demonstrated the ability of median nerve CSA to discriminate between normal and abnormal EDSs with an optimal cutoff CSA of ≥10 mm2, as well as, the ability to discriminate between mild CTS and moderate to severe CTS at a cutoff CSA of greater than or equal to 12 mm2. Conclusions: The results of this study show that US measurements of the median nerve at the distal wrist crease discriminate between normal and abnormal EDSs, and between mild CTS and moderate to severe CTS.

Ultrasound Cross-Sectional Area of the Median Nerve Is Not a Predictor of Patient Reported Outcomes After Carpal Tunnel Release.

BACKGROUND: The purpose of this study was to evaluate the relationship between cross sectional area (CSA) of the median nerve on ultrasound (US) with pre- and postoperative Boston Carpal Tunnel Questionnaire (BCTQ) scores. We hypothesize that there is a positive correlation between CSA and the ΔBCTQ after carpal tunnel release (CTR). METHODS: This was a single center study. During a 6-year period (2014-2020), CSA of the median nerve on US and BCTQ scores were collected prospectively for patients presenting with the chief complaint of numbness and tingling in the upper extremity. Patients who underwent CTR and presented for their 6-week follow-up had repeat measurements of the CSA and BCTQ. These patients were included in this study. Patients were then divided into ultrasound positive (CSA ≥ 10) and ultrasound negative (CSA < 10) groups. These groups were compared on the basis of demographics, preoperative BCTQ scores, postoperative BCTQ scores, and 6-week ΔBCTQ score. RESULTS: US-positive and-negative groups did not differ significantly in their preoperative BCTQ, postoperative BCTQ, or ΔBCTQ scores. Both groups did, however, experience significant improvement when comparing preoperative to postoperative BCTQ scores within their respective US group. CONCLUSION: Regardless of the preoperative CSA of the median nerve, patients who underwent CTR experienced a significant improvement in their BCTQ results. US-positive patients experienced no greater improvement than US-negative patients. These results would suggest that US is not a good predictor of subjective surgical outcome measures such as the BCTQ.

Changes in Cross-sectional Area of the Median Nerve and Boston Carpal Tunnel Questionnaire Scores After Carpal Tunnel Release.

BACKGROUND: We hypothesized that postoperative Boston Carpal Tunnel Questionnaire (BCTQ) scores and ultrasound (US) measurements of the median nerve cross-sectional area (CSA) at the distal wrist crease are significantly decreased at 2-week, 6-week, and ≥ 6 months follow-up appointments, compared with baseline values. METHODS: This study was a retrospective chart review of patients who presented to a single hand clinic with evidence of carpal tunnel syndrome over a 6-year period (2014-2020). Patients received baseline US measurements of the median nerve CSA as well as completion of the BCTQ, and for the patients who underwent carpal tunnel release (CTR), postoperative US measurements and questionnaire scores were obtained at 2 weeks, 6 weeks, or ≥ 6 months postoperatively. RESULTS: This study included 224 separate wrists. Median Nerve CSA measurements were 13.2 ± 4.5 mm2 at baseline, 11.9 ± 3.6 mm2 at 2 weeks postoperatively, 11.6 ± 4.5 mm2 at 6 weeks postoperatively, and 11.7 ± 4.3 mm2 at 6 months or more (P = .002). The BCTQ Symptom Severity Scale scores were 3.14 ± 0.76 at baseline, 1.76 ± 0.63 at 2 weeks, 1.68 ± 0.70 at 6 weeks, and 1.41 ± 0.64 at 6 months or longer (P < .001). The BCTQ Functional Status Scale scores were 2.56 ± 0.89 at baseline, 2.03 ± .1.0 at 2 weeks, 1.65 ± 0.77 at 6 weeks, and 1.36 ± 0.61 at 6 months or longer (P < .001). CONCLUSIONS: These findings demonstrated a sustained decrease in median nerve CSA and patient-reported outcomes following CTR at 2 weeks, 6 weeks, and between 6 and 12 months.