Accuracy in the Cross-Sectional Area of the Median Nerve at the Wrist Measured by Physical Medicine and Rehabilitation Residents

Natcha Homrossukhon; Chanasak Hathaiareerug; Chanwit Phongamwong

Authors

Natcha Homrossukhon Department of Rehabilitation Medicine, Phramongkutklao Hospital and Phramongkutklao College of Medicine
Chanasak Hathaiareerug Department of Rehabilitation Medicine, Phramongkutklao Hospital and Phramongkutklao College of Medicine
Chanwit Phongamwong Department of Rehabilitation Medicine, Phramongkutklao Hospital and Phramongkutklao College of Medicine

Keywords:

median nerve, cross-sectional area, ultrasound, accuracy, residency training

Abstract

Objectives: This study aimed to evaluate the accuracy of median nerve cross-sectional area (CSA) measurements at the wrist made by Physical Medicine and Rehabilitation (PMR) residents after a single training session.

Study design: Cross-sectional study

Setting: PMR Outpatient Unit, Phramongkutklao hospital, Bangkok, Thailand

Subjects: The study enrolled patients aged 20 years or over who had undergone median nerve conduction studies and were willing to sign the consent form.

Methods: A single-session ultrasound workshop on measuring the CSA of the median nerve at the wrist was provided to 17 PMR residents. Each resident was required to measure the median nerve CSA of five different wrists of patients who visited the electrodiagnostic laboratory in 2022-2023. The CSA was averaged from three separate measurements by each of the residents. Measurement of each wrist from a single expert physiatrist was considered as a reference standard. The intraclass correlation coefficient (ICC) was used to determine the accuracy of CSA measurement. Additionally, agreement on the determination of median nerve enlargement (≥12 cm²) was made using Cohen’s Kappa coefficient.

Results: Of 82 wrists, 64.0% were diagnosed with carpal tunnel syndrome (CTS) based on the electrodiagnosis study. The median nerve was correctly identified in 79 wrists (96.3%). The overall resident’s ICC was 0.948 (p < 0.001) compared with an expert physiatrist. The Kappa coefficient was 0.849 (p < 0.001), with a 92.4% agreement percentage.

Conclusions: US training sessions may benefit PMR residency programs. Further research is needed to determine optimal training duration and frequency and to assess long-term skill retention.

References

Rhee SY, Cho HE, Kim JH, Kim HS. Incidence and reappraisal of known risk factors associated with carpal tunnel syndrome: A nationwide, 11-year, population-based study in South Korea. J Clin Neurol [Internet]. 2021 [cited 2023 Oct 31]; 17: 524-33. Available from: https://pubmed.ncbi.nlm.nih.gov/34595860/ doi: 10.3988/jcn.2021.17.4.524

Alfonso C, Jann S, Massa R, Torreggiani A. Diagnosis, treatment and follow-up of the carpal tunnel syndrome: a review. Neurol Sci [Internet]. 2010 [cited 2023 Oct 31]; 31: 243-52. Available from: https://pubmed.ncbi.nlm.nih.gov/20145967/ doi: 10.1007/s10072-009-0213-9

Cartwright MS, Hobson-Webb LD, Boon AJ, Alter KE, Hunt CH, Flores VH, et al. Evidence-based guideline: neuromuscular ultrasound for the diagnosis of carpal tunnel syndrome. Muscle Nerve [Internet]. 2012 [cited 2023 Oct 31]; 46: 287-93. Available from: https://pubmed.ncbi.nlm.nih.gov/22806381/ doi: 10.1002/mus.23389

Fowler JR, Maltenfort MG, Ilyas AM. Ultrasound as a first-line test in the diagnosis of carpal tunnel syndrome: a cost-effectiveness analysis. Clin Orthop Relat Res [Internet]. 2013 [cited 2023 Oct 31]; 471: 932-7. Available from: https://pubmed.ncbi.nlm.nih.gov/23129465/ doi: 10.1007/s11999-012-2662-3

Salman Roghani R, Hashemi SE, Holisaz MT, Gohari F, Delbari A, Lokk J. The diagnostic accuracy of median nerve ultrasonography in elderly patients with carpal tunnel syndrome: sensitivity and specificity assessment. Clin Interv Aging [Internet]. 2018 [cited 2023 Oct 31]; 13: 1953-62. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6187921/ doi: 10.2147/CIA.S177307

Emril DR, Zakaria I, Amrya M. Agreement between high-resolution ultrasound and electrophysiological examinations for diagnosis of carpal tunnel syndrome in the Indonesian population. Front Neurol [Internet]. 2019 [cited 2023 Oct 31]; 10: 888. Available from: https://pubmed.ncbi.nlm.nih.gov/31507510/ doi: 10.3389/fneur.2019.00888

Yazdchi M, Tarzemani MK, Mikaeili H, Ayromlu H, Ebadi H. Sensitivity and specificity of median nerve ultrasonography in diagnosis of carpal tunnel syndrome. Int J Gen Med [Internet]. 2012 [cited 2023 Oct 31]; 5: 99-103. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273372/ doi: 10.2147/IJGM.S17785

Crasto JA, Scott ME, Fowler JR. Ultrasound measurement of the cross-sectional area of the median nerve: The effect of teaching on measurement accuracy. Hand (N Y) [Internet]. 2019 [cited 2023 Oct 31]; 14: 155-62. Available from: https://pubmed.ncbi.nlm.nih.gov/28929789/ doi: 10.1177/1558944717731857

Zumsteg JW, Ina JG, Merrell GA. Evaluation of the acquisition of ultrasound proficiency in hand surgery fellows. J Ultrasound Med [Internet]. 2019 [cited 2023 Oct 31]; 38: 2111-7. Available from: https://pubmed.ncbi.nlm.nih.gov/30648754/ doi: 10.1002/jum.14907

Tawfik EA, Cartwright MS. Guidelines for neuromuscular ultrasound training. Muscle & Nerve [Internet]. 2019 [cited 2023 Oct 31]: 361-6. Available from: https://pubmed.ncbi.nlm.nih.gov/31335971/

Junck AD, Escobedo EM, Lipa BM, Cronan M, Anthonisen C, Poltavskiy E, et al. Reliability assessment of various sonographic techniques for evaluating carpal tunnel syndrome. J Ultrasound Med [Internet]. 2015 [cited 2023 Oct 31]; 34: 2077-88. Available from: https://pubmed.ncbi.nlm.nih.gov/26453123/ doi: 10.1002/mus.26642

Georgiev GP, Karabinov V, Kotov G, Iliev A. Medical ultrasound in the evaluation of the carpal tunnel: A critical review. Cureus [Internet]. 2018 [cited 2023 Oct 31]; 10: e3487. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6314799/ doi: 10.7759/cureus.3487

Ziswiler H-R, Reichenbach S, Vögelin E, Bachmann LM, Villiger PM, Jüni P. Diagnostic value of sonography in patients with suspected carpal tunnel syndrome: a prospective study. Arthritis Rheum [Internet]. 2005 [cited 2023 Oct 31]; 52: 304-11. Available from: https://pubmed.ncbi.nlm.nih.gov/15641050/ doi: 10.1002/art.20723

Ghasemi M, Abrishamchi F, Basiri K, Meamar R, Rezvani M. Can we define severity of carpal tunnel syndrome by ultrasound? Adv Biomed Res [Internet]. 2015 [cited 2023 Oct 31]; 4: 138. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4544117/ doi: 10.4103/2277-9175.161537

Dumitru D. Preface. In: Dumitru D, Amato AA, Zwarts M editors. Electrodiagnostic medicine. 2nd ed. Boston: Hanley & Belfus; 2002. p.1061-70.

Chen S, Andary M, Buschbacher R, Del Toro D, Smith B, So Y, et al. Electrodiagnostic reference values for upper and lower limb nerve conduction studies in adult populations. Muscle Nerve [Internet]. 2016 [cited 2023 Oct 31]; 54: 371-7. Available from: https://pubmed.ncbi.nlm.nih.gov/27238640/ doi: 10.1002/mus.25203

Walter SD, Eliasziw M, Donner A. Sample size and optimal designs for reliability studies. Stat Med [Internet]. 1998 [cited 2023 Oct 31]; 17: 101-10. Available from: https://pubmed.ncbi.nlm.nih.gov/9463853/ doi: 10.1002/(sici)1097-0258(19980115)17:1<101::aid-sim727>3.0.co;2-e

Koo TK, Li MY. A Guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med [Internet]. 2016 [cited 2023 Oct 31]; 15: 155-63. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4913118/ doi: 10.1016/j.jcm.2016.02.012

McHugh ML. Interrater reliability: the kappa statistic. Biochem Med (Zagreb) [Internet]. 2012 [cited 2023 Oct 31]; 22: 276-82. Available from: https://pubmed.ncbi.nlm.nih.gov/23092060/

Cartwright MS, Hobson-Webb LD, Boon AJ, Alter KE, Hunt CH, Flores VH, et al. Evidence-based guideline: neuromuscular ultrasound for the diagnosis of carpal tunnel syndrome. Muscle Nerve [Internet]. 2012 [cited 2023 Oct 31]; 46: 287-93. Available from: https://pubmed.ncbi.nlm.nih.gov/22806381/ doi: 10.1002/mus.23389

Asghar A, Patra A, Satish Ravi K, Tubbs RS, Kumar A, Naaz S. Bifid median nerve as an anatomical risk factor for carpal tunnel syndrome: A meta-analysis. Clin Anat [Internet]. 2022 [cited 2023 Oct 31]; 35: 946-52. Available from: https://pubmed.ncbi.nlm.nih.gov/35489054/ doi: 10.1002/ca.23900

Yerasu MR, Ali M, Rao R, Murthy JMK. Bifid median nerve: a notable anomaly in carpal tunnel syndrome. BMJ Case Rep [Internet]. 2022 [cited 2023 Oct 31]; 15. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9114938/ doi: 10.1136/bcr-2022-249220