Sonographic examination of the median nerve in dialysis patients and after renal transplantation

Ultrasound-Based Multi-Planar Bilateral Comparisons as a Diagnostic and Treatment-Definition Method for Unilateral Peripheral Nerve Entrapment

OBJECTIVE

The primary goal was to determine the performance of the cross-section area swelling rate (CSASR) for diagnostic and therapeutic purposes based on the reference standard of electrodiagnosis examination (EDX) in this diagnostic test study.

METHODS

First, patients with symptoms like unilateral carpal tunnel syndrome (CTS), cubital tunnel syndrome (CuTS), and radial nerve compression (RNC) underwent EDX and ultrasound examination. Second, patients with positive ultrasound were calculated for the CSASR of diseased nerve. Based on previously established CSASR criteria, each patient was categorized as having or not having peripheral nerve entrapment, and for those meeting diagnostic criteria, non-surgical or surgical treatment was recommended. Then, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy rate (ACC) of ultrasound diagnosis and therapeutic decision-making were calculated based on the reference standard of EDX that had been historically used in the practice.

RESULTS

The total sensitivity, specificity, PPV, NPV, and ACC of ultrasound diagnosis are respectively 93.4, 85.2, 94.7, 82.1, and 91.3%. Which of therapeutic decision-making by ultrasound are, respectively, 83.3, 52.2, 78.4, 60.0, and 73.2%.

CONCLUSION

The sensitivity and Youden's index of CSASR diagnostic threshold for CuTS is higher than other ultrasound methods. The CSASR diagnostic threshold for CuTS has a potential diagnostic role, but the current date is still not enough to support the potential diagnostic role for CTS or RNS. There is insufficient evidence to suggest that CSASR for CuTS can be used in isolation for diagnosis. Additional research is needed to confirm the diagnostic role of CSASR. The current results suggest that this ultrasound examination method is not suitable for therapeutic decision-making.

Diagnosis of carpal tunnel syndrome in non-diabetic patients with hemodialysis using ultrasound: Is it a useful adjunctive tool?

OBJECTIVE

(1) To examine the ultrasound (US) characteristics in patients with hemodialysis-related carpal tunnel syndrome (H-CTS) and (2) to evaluate the accuracy of a proposed US parameter-dynamic ratio of median nerve-to-hamate hook distance (RMHD) in diagnosis of H-CTS.

DESIGN

A case-control study.

SETTING

In a tertiary medical center and a secondary hospital from Nov. 2017 to Mar. 2021.

PARTICIPANTS

Consecutive non-diabetes patients under hemodialysis were recruited and divided into a hemodialysis without CTS (H-Control) group and an H-CTS group. Age-matched volunteers without diabetes or upper extremity disorders were enrolled as the Control group.

INTERVENTION

Ultrasound examinations by two operators blinded to the patient's clinical information.

MAIN OUTCOME MEASURES

US parameters including cross-sectional area of the median nerve at the carpal tunnel inlet (CSA-I) and outlet (CSA-O), the flattening ratio of the median nerve at the inlet (FR-I) and outlet (FR-O), and RMHD.

RESULTS

Handedness and arteriovenous fistula showed no associations with CSA-I/O and FR-I/O. Compared with Control group (n=69), the CSA-I was significantly larger in the H-Control group (n=63) and H-CTS group (n=76) (p<0.05). There were no significant differences in the FR-I/-O among the three groups. For the second aim, in the H-CTS group(n=38), there was a significantly lower RMHD compared with both the Control (n=20) and H-Control groups (n=30) (0.1%±2.2% versus 3.5±2.3% and 3.8±1.7%, p<0.05). An RMHD cutoff value of <2.7% yielded a specificity of 80.0%, a sensitivity of 94.7%, and an overall accuracy of 88.2% in the diagnosis of H-CTS.

CONCLUSIONS

Neither CSA-I/-O or FR-I/-O have a role in the diagnosis of H-CTS. RMHD might be a useful US parameter in the diagnosis of CTS in non-diabetic patients undergoing hemodialysis.

Shear Wave Velocity Measurements of the Median Nerve in Patients on Chronic Hemodialysis

OBJECTIVES

Chronic dialysis causes changes in the structure of median nerve. This is a risk for the development of carpal tunnel syndrome in patients on dialysis. The aim of the present study was to evaluate the diagnostic capacity of shear wave velocity (SWV) and the cross-sectional area (CSA) to detect the structural changes of the median nerve in patients with end-stage chronic kidney disease on hemodialysis.

METHODS

Twenty-five patients with chronic kidney disease undergoing hemodialysis 3 times per week and 26 healthy controls were included. None of the participants had any signs or symptoms of carpal tunnel syndrome specified according to the criteria of the American Academy of Neurology Practice Parameters. Both patients and controls underwent sonographic and elastographic examinations of the median nerves in both hands to evaluate CSA and SWV values, and they were compared regarding these parameters.

RESULTS

The mean CSA of the median nerve in the chronic hemodialysis group was significantly higher than that in the control group (12.74 ± 1.88 mm² versus 8.89 ± 1.45 mm² ; P < .001). The mean longitudinal and axial SWV values in the hemodialysis group (3.86 ± 0.54 m/s and 3.92 ± 0.52 m/s, respectively) were significantly higher than those in the control group (2.98 ± 0.31 m/s and 3.04 ± 0.31 m/s, respectively; P < .001).

CONCLUSIONS

Patients on chronic hemodialysis had higher mean CSA and SWV values of the median nerve compared with the healthy controls. Structural changes in the median nerve that occur in patients on chronic hemodialysis can be detected by shear-wave sonoelastography.

Clinical and ultrasonographic screening for carpal tunnel syndrome in hemodialysis patients

Background

Carpal tunnel syndrome (CTS) is one of the most common complications among hemodialysis (HD) patients. This study aimed to assess the prevalence of CTS in HD patients using clinical and noninvasive ultrasound (US) criteria.

Methods

A cross-sectional, observational study was conducted on 94 HD patients to evaluate CTS manifestations and demographic, clinical, and laboratory data. The median nerve (MN) cross sectional area (CSA) (MN-CSA) was estimated by US examination at the pisiform and hamate levels. Both hands were evaluated, and the higher MN-CSA was considered.

Results

Neuropathic pain and nocturnal numbness at MN distribution were present in 40.4% and 18.1%, respectively, while Tinel’s test was positive in 25.5% of patients. A MN-CSA ≥ 11.5 mm² identified the probability of CTS with 63% sensitivity and 80% specificity. Patients with CTS had higher serum calcium (P = 0.02) and lower parathyroid hormone (PTH) (P = 0.02). CTS was frequently developed on the same side of an arteriovenous fistula. The MN-CSA had positive correlations with age, serum phosphorus, and visual analogue scale (VAS) score (P = 0.01, 0.01, and 0.03 respectively) and a negative correlation with PTH level (P = 0.007). Serum phosphorus level (P = 0.015) and VAS (P = 0.04) were the significant predictors of MN-CSA.

Conclusion

CTS appears to frequently occur in HD patients. US examination may be helpful in detection of CTS and can be an alternative to electrodiagnostic studies in HD patients.

Sonographic examination of the median nerve in dialysis patients and after renal transplantation

OBJECTIVE

Patients with renal insufficiency are predisposed to develop CTS (carpal tunnel syndrome). In particular, long-term dialysis seems to contribute to changes in median nerve texture which lead to an increased risk for CTS. The current study was designed to evaluate if these structural changes can be detected by HRS (high-resolution sonography). Additionally, the current study aimed to determine if changes are reversible after termination of dialysis.

METHODS

Fifty patients (98 hands) were included in the study. The study population was subdivided into three groups: patients without any history of renal disease (H, n = 20), patients with long-term dialysis (D, n = 10), and patients after renal transplantation (TX, n = 20). None of the patients had any clinical symptoms for a median nerve compression syndrome. The CSA (cross-sectional area) of the median nerve was evaluated both 12 cm proximally of the carpal tunnel inlet and directly at the carpal tunnel inlet. The ratio of those two values, the WFR (wrist forearm ratio), was calculated and analyzed.

RESULTS

The CSA demonstrated significantly higher values in dialysis (D) and transplanted (TX) patients compared to the healthy (H) control group (P < 0.001). No significant differences were detectable between the D and TX groups. Specifically, there was no significant difference in the WFR.

CONCLUSION

Patients with chronic renal disease demonstrate significantly higher CSA values compared to their healthy counterparts. Termination of dialysis does not seem to reverse these morphological changes.