{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T11:35:19Z","timestamp":1785497719026,"version":"3.56.0"},"reference-count":14,"publisher":"BMJ","issue":"1","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Pract Neurol"],"accepted":{"date-parts":[[2022,8,24]]},"published-print":{"date-parts":[[2023,2]]},"abstract":"<jats:p>A 21-year-old woman developed an acute myotonic reaction while undergoing anaesthesia using succinylcholine. Examination later showed she had shoulder, neck and calf hypertrophy, bilateral symmetrical ptosis and eyelid, handgrip and percussion myotonia. Peripheral neurophysiology studies identified significant, continuous myotonic discharges in both upper and lower limbs. Genetic analysis identified a c.3917G&gt;A (p.Gly1306Glu) mutation in the <jats:italic>SCN4A<\/jats:italic> gene, confirming a diagnosis of sodium channel myotonia. Succinylcholine and other depolarising agents can precipitate life-threatening acute myotonic reactions when given to patients with myotonia. Patients with neuromuscular disorders are at an increased risk of perioperative anaesthetic complications. We report a woman who developed an acute myotonic reaction whilst undergoing anaesthesia, in the context of an unrecognised myotonic disorder. We then discuss an approach to the diagnosis of myotonic disorders.<\/jats:p>","DOI":"10.1136\/pn-2022-003352","type":"journal-article","created":{"date-parts":[[2022,10,3]],"date-time":"2022-10-03T13:21:59Z","timestamp":1664803319000},"page":"74-77","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":6,"title":["Acute myotonic reaction during succinylcholine anaesthesia"],"prefix":"10.1136","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5640-0877","authenticated-orcid":false,"given":"Saeed Rashaad","family":"Mohammed","sequence":"first","affiliation":[{"name":"Department of Clinical Medical Sciences, The University of the West Indies at St Augustine Faculty of Medical Sciences, St Augustine, Trinidad and Tobago"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefan","family":"Gafoor","sequence":"additional","affiliation":[{"name":"Department of Medicine, Eric Williams Medical Sciences Complex Compound, Champ Fleurs, Trinidad and Tobago"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Avidesh","family":"Panday","sequence":"additional","affiliation":[{"name":"Department of Clinical Medical Sciences, The University of the West Indies at St Augustine Faculty of Medical Sciences, St Augustine, Trinidad and Tobago"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2022,10,3]]},"reference":[{"key":"2025090410214497000_23.1.74.1","article-title":"New diagnostic and therapeutic modalities in neuromuscular disorders in children","volume":"51","author":"Chikkannaiah","year":"2021","journal-title":"Curr Probl Pediatr Adolesc Health Care"},{"key":"2025090410214497000_23.1.74.2","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1002\/mus.20923","article-title":"Differential diagnosis of myotonic disorders","volume":"37","author":"Miller","year":"2008","journal-title":"Muscle Nerve"},{"key":"2025090410214497000_23.1.74.3","doi-asserted-by":"publisher","DOI":"10.1016\/j.pediatrneurol.2007.09.007"},{"key":"2025090410214497000_23.1.74.4","unstructured":"NCBI . 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