{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T16:17:36Z","timestamp":1787761056109,"version":"build-2784847793"},"reference-count":18,"publisher":"BMJ","issue":"2","license":[{"start":{"date-parts":[[2025,5,28]],"date-time":"2025-05-28T00:00:00Z","timestamp":1748390400000},"content-version":"unspecified","delay-in-days":27,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Sociedade Portuguesa de Reumatologia","award":["5000"],"award-info":[{"award-number":["5000"]}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["RMD Open"],"accepted":{"date-parts":[[2025,4,29]]},"published-print":{"date-parts":[[2025,5]]},"abstract":"<jats:sec>\n                  <jats:title>Objectives<\/jats:title>\n                  <jats:p>To assess the value of adding the ultradistal level to other more thoroughly studied levels of the carpal tunnel when measuring the cross-sectional area (CSA) of the median nerve (MN) by ultrasound (US) in diagnosing patients with primary carpal tunnel syndrome (CTS).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>Patients clinically diagnosed with primary CTS and healthy controls were included. The MN-CSA was measured by US at three wrist levels: proximal, distal and ultradistal. The best cut-off to differentiate cases and controls was determined for the CSA and for the difference between levels of the same wrist. The performance of different definitions for US-CTS compared with the clinical diagnosis of CTS was evaluated: (1) CSA above cut-off at each level; (2) CSA-difference above cut-off at each level; (3) \u22651 level with CSA above cut-off and (4) \u22651 CSA-difference above cut-off. Definition 3, excluding the ultradistal level, and combinations of definitions were also tested.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>In total, 219 patients and 39 controls were included. The CSA was higher in patients (10.5\u201316.8\u2009mm<jats:sup>2<\/jats:sup>) than controls (6.2\u20137.6\u2009mm<jats:sup>2<\/jats:sup>). The difference between groups was maximal at the ultradistal level (right: 10.1 mm<jats:sup>2<\/jats:sup>; left: 8.3 mm<jats:sup>2<\/jats:sup>). The CSA cut-offs were 11 mm<jats:sup>2<\/jats:sup>, 9 mm<jats:sup>2<\/jats:sup> and 10 mm<jats:sup>2<\/jats:sup> at the right, and 10 mm<jats:sup>2<\/jats:sup>, 8 mm<jats:sup>2<\/jats:sup> and 10 mm<jats:sup>2<\/jats:sup> at the left, for the proximal, distal and ultradistal levels, respectively. Definition 3 yielded the best balance between sensitivity (98%) and specificity (95%) (right hand). Removing the ultradistal level from definition 3 decreased sensitivity to 90%, maintaining the same specificity.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Adding the ultradistal level improves the performance of US for diagnosing CTS. We suggest adding it in clinical practice when investigating CTS.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/rmdopen-2025-005563","type":"journal-article","created":{"date-parts":[[2025,5,29]],"date-time":"2025-05-29T03:50:15Z","timestamp":1748490615000},"page":"e005563","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":3,"title":["Diagnosis of carpal tunnel syndrome with ultrasound: should we go more distal?"],"prefix":"10.1136","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5629-7961","authenticated-orcid":false,"given":"Tom\u00e1s","family":"Fontes","sequence":"first","affiliation":[{"name":"Rheumatology, Hospital do Divino Esp\u00edrito Santo de Ponta Delgada EPE, Ponta Delgada, Portugal"},{"name":"Rheumatology, Unidade Local de Sa\u00fade de Tr\u00e1s-os-Montes e Alto Douro, Vila Real, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1954-0229","authenticated-orcid":false,"given":"Alexandre","family":"Sepriano","sequence":"additional","affiliation":[{"name":"CHRC Campus Nova Medical School, Lisboa, Portugal"},{"name":"Leiden Universitair Medisch Centrum, Leiden, Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8899-9087","authenticated-orcid":false,"given":"Sofia","family":"Ramiro","sequence":"additional","affiliation":[{"name":"Department of Rheumatology, Leiden University Medical Center, Leiden, Netherlands"},{"name":"Department of Rheumatology, Zuyderland Medical Centre Heerlen, Heerlen, Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paula","family":"Moniz","sequence":"additional","affiliation":[{"name":"Plastic and Reconstructive Surgery, Hospital do Divino Esp\u00edrito Santo de Ponta Delgada EPE, Ponta Delgada, Azores, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5380-7180","authenticated-orcid":false,"given":"Carolina","family":"Furtado","sequence":"additional","affiliation":[{"name":"Rheumatology, Hospital do Divino Esp\u00edrito Santo de Ponta Delgada EPE, Ponta Delgada, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guilherme","family":"Figueiredo","sequence":"additional","affiliation":[{"name":"Rheumatology, Hospital do Divino Esp\u00edrito Santo de Ponta Delgada EPE, Ponta Delgada, Portugal"},{"name":"Rheumatology, CAL-Cl\u00ednica do Aparelho Locomotor, Ponta Delgada, Azores, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandra","family":"Falc\u00e3o","sequence":"additional","affiliation":[{"name":"iNOVA4Health, NOVA Medical School, Lisbon, Portugal"},{"name":"Rheumatology, Unidade Local de Sa\u00fade Loures \u2013 Odivelas, EPE, Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,5,28]]},"reference":[{"key":"2025090312391537000_11.2.e005563.1","doi-asserted-by":"publisher","DOI":"10.1016\/s1474-4422(16)30231-9"},{"key":"2025090312391537000_11.2.e005563.2","first-page":"6","article-title":"Carpal tunnel syndrome","volume":"77","author":"Aroori","year":"2008","journal-title":"Ulster Med J"},{"key":"2025090312391537000_11.2.e005563.3","unstructured":"Sevy JO , Syndrome VMCT . StatPearls. Treasure Island (FL): StatPearls Publishing Copyright \u00a9 2023. StatPearls Publishing LLC, 2023."},{"key":"2025090312391537000_11.2.e005563.4","doi-asserted-by":"publisher","DOI":"10.1177\/1753193415625404"},{"key":"2025090312391537000_11.2.e005563.5","first-page":"993","article-title":"Carpal Tunnel Syndrome: Diagnosis and Management","volume":"94","author":"Wipperman","year":"2016","journal-title":"Am Fam Physician"},{"key":"2025090312391537000_11.2.e005563.6","doi-asserted-by":"crossref","first-page":"851","DOI":"10.5603\/FM.a2021.0121","article-title":"Carpal tunnel syndrome: state-of-the-art review","volume":"81","author":"Osiak","year":"2022","journal-title":"Folia Morphol (Warsz)"},{"key":"2025090312391537000_11.2.e005563.7","doi-asserted-by":"publisher","DOI":"10.1016\/j.ultrasmedbio.2012.02.026"},{"key":"2025090312391537000_11.2.e005563.8","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1055\/s-0041-1741088","article-title":"Ultrasound of Median Nerve in the Diagnosis of Carpal Tunnel Syndrome-Correlation with Electrophysiological Studies","volume":"32","author":"Kanagasabai","year":"2022","journal-title":"Indian J Radiol Imaging"},{"key":"2025090312391537000_11.2.e005563.9","doi-asserted-by":"crossref","DOI":"10.1186\/s13643-018-0929-9","article-title":"Sonographic reference values of median nerve cross-sectional area: a protocol for a systematic review and meta-analysis","volume":"8","author":"Takata","year":"2019","journal-title":"Syst Rev"},{"key":"2025090312391537000_11.2.e005563.10","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2012-202328"},{"key":"2025090312391537000_11.2.e005563.11","first-page":"4","article-title":"Pathophysiology of carpal tunnel syndrome","volume":"20","author":"Aboonq","year":"2015","journal-title":"Neurosciences (Riyadh)"},{"key":"2025090312391537000_11.2.e005563.12","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/j.crad.2017.07.025","article-title":"Ultrasound carpal tunnel syndrome: additional criteria for diagnosis","volume":"73","author":"Ng","year":"2018","journal-title":"Clin Radiol"},{"key":"2025090312391537000_11.2.e005563.13","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1007\/s00256-019-03291-0","article-title":"MRI criteria for diagnosis and predicting severity of carpal tunnel syndrome","volume":"49","author":"Ng","year":"2020","journal-title":"Skeletal Radiol"},{"key":"2025090312391537000_11.2.e005563.14","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1002\/ajum.12219","article-title":"Ultrasound parameters to identify and diagnose carpal tunnel syndrome. A review of the literature","volume":"23","author":"Linehan","year":"2020","journal-title":"Australas J Ultrasound Med"},{"key":"2025090312391537000_11.2.e005563.15","doi-asserted-by":"publisher","DOI":"10.1177\/1753193412469581"},{"key":"2025090312391537000_11.2.e005563.16","article-title":"A Comparative Analysis Between Ultrasound and Electromyographic and Nerve Conduction Studies in Diagnosing Carpal Tunnel Syndrome (CTS): A Systematic Review and Meta-Analysis","volume":"14","author":"Zaki","year":"2022","journal-title":"Cureus"},{"key":"2025090312391537000_11.2.e005563.17","doi-asserted-by":"publisher","DOI":"10.1007\/s11999-010-1637-5"},{"key":"2025090312391537000_11.2.e005563.18","doi-asserted-by":"crossref","first-page":"1085","DOI":"10.1007\/s10067-020-05293-z","article-title":"Ultrasound assessment of carpal tunnel in rheumatoid arthritis and idiopathic carpal tunnel syndrome","volume":"40","author":"Smerilli","year":"2021","journal-title":"Clin Rheumatol"}],"container-title":["RMD Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/rmdopen-2025-005563","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T19:39:26Z","timestamp":1756928366000},"score":1,"resource":{"primary":{"URL":"https:\/\/rmdopen.bmj.com\/lookup\/doi\/10.1136\/rmdopen-2025-005563"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,5]]},"references-count":18,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025,5,28]]},"published-print":{"date-parts":[[2025,5]]}},"alternative-id":["10.1136\/rmdopen-2025-005563"],"URL":"https:\/\/doi.org\/10.1136\/rmdopen-2025-005563","relation":{},"ISSN":["2056-5933"],"issn-type":[{"value":"2056-5933","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5]]}}}