Neurogenic thoracic outlet syndromes (TOS) are dominated by the nonspecific forms. This study focuses only on the rarer true forms related to proximal nerve compression in the thoracic outlet, with the presence of motor (atrophy of the hand's intrinsic muscles) and/or sensory (hypoesthesia in the territory of the medial antebrachial cutaneous nerve) deficits. The objectives of this study were to define the clinical characteristics, anatomical causes and surgical results of this condition.

Single-center retrospective study of 53 consecutive cases in 50 patients with an objective clinical deficit confirmed by nerve conduction studies. The population consisted of 47 adults and 3 children, 9 males and 41 females, with a mean age of 39 years (9-80 years), diagnosed between July 1994 and December 2019. An objective motor deficit was present in 50 cases, with the remaining 3 having a sensory deficit only. Forty cases underwent surgery, most often via the supraclavicular approach, while 13 cases did not undergo surgery because their deficit was longstanding and non-progressive.

One operated patient was lost in follow-up. An analysis of the medical records of 18 cases, including 15 operated cases found complete recovery in 4 cases, significant improvement in 9 cases and small improvement in 2 cases at a mean follow-up of 53 months (1-162 months). Thirty-four cases were reviewed in person, including 24 operated cases and evaluated with a mean follow-up of 135 months (36-284 months): the pain had disappeared in 21 cases, thenar atrophy persisted in 17 cases, which was associated with a claw-hand deformity in 3 cases, while 2 cases had an isolated claw-hand deformity. The patients were very satisfied with the procedure in 15 cases and satisfied in 9 cases. They evaluated the benefit of surgery at 87% and their upper limb function increased from 38% (10-60%) preoperatively to 77% (60-100%) at the review.

Few studies in the literature have focused on true neurogenic TOS cases. The treatment is surgical in progressive cases; an anatomical anomaly is always present. Surgical treatment eliminates the pain and helps to stabilize or even partially resolve the deficit. Despite a moderate objective gain, the patients’ feeling of functional improvement is important with a high satisfaction rate.

IV, retrospective.