Painless atrophy in the hand: Is it due to true neurogenic thoracic outlet syndrome or syringomiyelia? [Elde aǧrisiz atrofi: Gerçek nörojenik toraks çikişi sendromuna mi siringomiyeliye mi baǧli?]

A patient with true neurogenic thoracic outlet syndrome (ntos) who was presented with fairly perplexing features is reported. a 17-year-old young lady was complaining of the wasting of right hand muscles which had been noticed 5 years ago and worsen gradually thereafter. a magnetic resonance imaging (mri) study performed previously revealed a syringomyelic cavity between c3 and t1 vertebral levels with the widest diameter of 2.5 mm. on her neurological examination,a weakness and atrophy was found in right hand and medial forearm muscles,which was most prominent in the thenar region,adson test was positive on the right side. in the nerve conduction studies,right medial antebrachial cutaneous sensory nerve action potential was unrecordable and amplitude of right median compound muscle action potential was decreased. needle electromyography findings were compatible with chronic neurogenic involvement in the right-hand muscles. mri showed a non-enhancing expansion in the proximal extraforaminal segment of t1 nerve root. ultrasonography revealed a narrowing of the right subclavien artery traversing the scalene triangle which is more evident during abduction of the right arm. complete first rib resection with the release of the muscles and fibrous bands causing the compression was performed through a transaxillary approach. ntos was diagnosed in this patient with the aid of characteristic clinical and electrophysiological findings along with the small diameter of the syringomyelia for producing clinical symptoms. t1 nerve root swelling was presented as an interesting and rare radiological finding.