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

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.