True neurogenic thoracic outlet syndrome in a competitive swimmer: a case report of this rare association

Abstract

-True neurogenic thoracic outlet syndrome (TOS) is an uncommon disorder despite of be a frequent reason for referral to the EMG laboratories. We describe the second case in the literature of true TOS in a competitive swimmer with progressive weakness and severe atrophy of the left thenar eminence. EMG showed lower trunk plexopathy. X-ray and MRI of the cervical spine and brachial plexus were normal. Surgical exploration evidenced the lower trunk retracted and pulled by a fibrous band. It was excised and neurolysis of the plexus was done with gradual improvement of function. We discuss the possible pathophysiology of this association.KEY WORDS: thoracic outlet syndrome, swimming, brachial plexopathy.Síndrome do desfiladeiro torácico verdadeiro em um nadador competitivo: relato de caso desta rara associação RESUMO -A síndrome do desfiladeiro torácico verdadeiro é condição incomum, apesar de ser uma razão freqüente de encaminhamento aos laboratórios de eletroneuromiografia. Nós descrevemos o segundo caso na literatura desta doença rara em um nadador competitivo com fraqueza e atrofia severa da eminência tenar esquerda. A ENMG mostrou plexopatia do tronco inferior. O RX e as ressonâncias magnéticas da coluna cervical e do plexo braquial foram normais. Exploração cirúrgica mostrou o tronco inferior tracionado por uma banda fibrosa. Ela foi ressecada e procedeu-se a neurólise do plexo com melhora gradual da função. Nós discutimos a possível fisiopatologia desta associação. PALAVRAS-CHAVE: síndrome do desfiladeiro torácico, natação, plexopatia braquial. Dr. Shin J. Oh -Department of Neurology / The University of Alabama at Birmingham/ UAB Station -Birmingham, Alabama 35294, USA. E-mail: shinjoh@uab.eduThoracic outlet syndrome (TOS) is a term coined by Peet et al in 1956 to a wide variety of symptoms originated by compression of the neurovascular bundle at the transition between the neck and axilla 1 . There are very few diseases so controversial in the medical literature such as TOS 2,3 . Based on these controversies, the TOS can be divided in vascular and neurogenic 3 . The vascular TOS can be subdivided in arterial and venous according to the compression of the subclavian artery or vein respectively. They result in ischemia of the digits and hand or swelling of the arm and represent only 5% of the patients with TOS 4 . The neurogenic TOS represent the rest 95% and can be subdivided in true and disputed.Following the ongoing debate in regard to the entity of TOS over the past two decades, a consensus has emerged that classic (true) neurogenic TOS is uncommon and is usually caused by compression of the lower trunk of the brachial plexus due to a cervical rib or band and enlarged scalenus muscles [5][6][7] . This compression results in arm pain, numbness of the inner surface of the hand and forearm, and characteristic wasting and weakness of the thenar and intrinsic hand muscles. Distinct electrophysiological abnormalities (low compound muscle action potential in the thenar and intrinsic muscles, abnormal sens...

Epidemiology of Injuries and Prevention Strategies in Competitive Swimmers

“…Physicians treating competitive swimmers should also be aware of several less common injuries, including thoracic outlet syndrome, 1 sternoclavicular joint subluxation, 13 os acromiale, 6 proximal vascular obstruction due to muscle hypertrophy, 47 rib stress fractures, 45 and exertional compartment syndrome of the forearm. 41 …”

True Neurogenic Thoracic Outlet Syndrome Following Hyperabduction during Sleep - A Case Report -

“…Almeida et al8 and Katirji and Hardy9 reported a case of true neurogenic TOS in swimmers. In swimmers, scalene muscle hypertrophy due to repetitive use of neck and shoulder muscles was considered to be a cause of nerve compression.…”

Thoracic outlet syndrome: A case with scalene muscle hypertropy who was followed by a long time in the diagnosis of cervical discopathy

“…Ayrıca medial antebrakiyal sinir iletimi bozuk olabilir. [7] Elektromiyografi karpal tünel, kubital tünel, omuz-el sendromu gibi problemlerden TOS'nin ayrılabilmesi için yardımcıdır. Le Forestier ve ark.nın yaptığı bir çalışmada klinik bulgularıyla nörojenik TOS tanısı konularak cerrahisi planlanan altı hastanın elektrofizyolojik incelemeleri yapıldığında sadece iki hastada nörojenik TOS saptanmış geri kalan hastalar ise karpal tunel sendromu, servikal radikülopati ve motor nöron hastalı-ğı gibi tanılar almıştır.…”

“…[7] Torasik outlet sendromlu hastalarda %98 oranında fibröz bantlar vardır. Yapı-lan kadavra çalışmalarında TOS dışı kişilerde bu oran %33'dür.…”