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Carpal tunnel syndrome (CTS) is the most frequent peripheral compression neuropathy. Anatomic variations may be encountered during carpal tunnel surgery.1–3 Compression of the median nerve at the wrist is frequently encountered. Carpal tunnel syndrome usually occurs without any obvious extrinsic causes; several cases have however been reported caused by anomalous or hypertrophic muscles. A survey of the literature shows that compression neuropathy of the median nerve has been reported in relation with anomalies affecting three muscles: the first (or second) lumbrical, the palmaris longus and its anatomic variants and the superficial flexor of long fingers. We can suspect the presence of such an anomalous muscle when the compression syndrome concerns a patient who is not within the “usual” age group with symptoms initiated or aggravated by physical exercise.
This report presents three cases of carpal tunnel syndrome caused by anatomic anomalousmuscles diagnosed peroperatively.
Sbai MA, Benzarti S, Msek H, Boussen M, Khorbi A. Carpal tunnel syndrome caused by lipoma: A case report. The Pan African Medical Journal. 2015;22:51.
Afshar, A. Palmaris profundus as the cause of carpal tunnel syndrome. Archives of Iranian Medicine. 2009;12(4):415-416.
Lindley SG, Kleinert JM. Prevalence of anatomic variations encountered in elective carpal tunnel release. J Hand Surg Am. 2003;28(5):849-55.
De Smet L. Median and ulnar nerve compression at the wrist caused by anomalous muscles. Acta Orthop Belg. 2002;68(5):431-8.
Cobb TK, An KN, Cooney WP, Berger RA. Lumbrical muscle incursion into the carpal tunnel during finger flexion. J Hand Surg Br. 1994;19(4):434-8.
Carroll M, Montero C. Rare anomalous muscle cause of carpal tunnel syndrome. Orthop. Rev. 1980;9:83-85.
Butler B. Jr, Bigley E. C. Jr. Aberrant index (first) lumbrical tendinous origin associated with carpal-tunnel syndrome. A case report. J Bone Joint Surg Am. 1971;53(1): 1602.
Hutton P, Kernohan J, Birch R. An anomalous flexor digitorum superficialis indicis muscle presenting as carpal tunnel syndrome. Hand. 1981;13(1):85-6.
Neviaser RJ. Flexor digitorum superficialis indicis and carpal tunnel syndrome. Hand. 1974;6(2):155-6.
Smith RJ. Anomalous muscle belly of the flexor digitorum superficialis causing carpal-tunnel syndrome. Report of a case. J Bone Joint Surg Am. 1971;53(6):1215-6.
Brones MF, Wilgis EFS. Anatomical variations of the palmaris longus, causing carpal tunnel syndrome: Case reports. Plastic and Reconstructive Surgery. 1978; 62(5):798-800.
Tountas CP, MacDonald CJ, Bihrle DM. Carpal tunnel syndrome. A review of 507 patients. Minn Med. 1983;66:479–482.
Reimann AF, Daseler ED, Anson BJ, Beaton LE. The palmaris longus muscle and tendon. A study of 1600 extremities. Anat Rec. 1944;89:495–505.
Dyreby JR, Engber WD. Palmaris profundus rare anomalous muscle. J Hand Surg [Am]. 1982;7:513–514.
Kang HJ, Jung SH, Yoon HK, Hahn SB, Kim SJ. Carpal tunnel syndrome caused by space occupying lesions. Yonsei Med J. 2009;50(2):257–261.
Bakriga B, Amouzou KS, Ayouba G, Kombate, N, Dellahn Y, Walla A, et al. Anomalous muscles: A rare cause of carpal tunnel syndrome: A case report. International Journal of Orthopaedics. 2017;4(1):705-07.
Javed S, Woodruff M. Carpal tunnel syndrome secondary to an accessory flexor digitorum superficialis muscle belly: Case report and review of the literature. Hand (NY). 2014;9(4):554-55.
Laxminarayan Bhandari, Michelle Palazzo. Anomalous muscles encountered in the carpal tunnel: A report of two cases. Journal of Clinical and Diagnostic Research. 2017;PD03-PD04.
Suk JI, Walker FO, Cartwright MS. Ultrasonography of peripheral nerves. Curr Neurol Neurosci Rep. 2013;13(2): 328.