Thoracic outlet decompression surgery for Gilliatt-Sumner hand as a presentation of neurogenic thoracic outlet syndrome.

BACKGROUND: Chronic compression of the inferior trunk of the brachial plexus can result in severe pain and progressive atrophy and weakness of the musculature of the forearm and hand, known as Gilliatt-Sumner hand (GSH). The objective of treatment for these patients is to stop further atrophy and pain. Restoration of motor function has been thought to be seldom achieved. The aim of the present contemporary case series was to describe the diagnosis, treatment, and outcomes of surgery for GSH. METHODS: All patients referred between January 2017 and May 2021 with visible signs of a GSH were included. Visible GSH signs were defined as muscle atrophy of the abductor digiti minimi, abductor pollicis brevis, and/or interosseous musculature. All the patients had undergone additional electrodiagnostic (ED) assessments and high-resolution ultrasound (HRUS) studies. All the patients with a diagnosis of GSH had undergone thoracic outlet decompression (TOD) surgery using a transaxillary or supraclavicular approach. The outcomes were measured using the thoracic outlet syndrome disability scale, cervical brachial symptom questionnaire, and disability of the arm, shoulder, and hand scale scores and patient-reported outcomes of motor function, measured using a numerical rating scale (NRS). The standardized elevated arm stress test (sEAST) was used to assess the patients' motor function before and after TOD surgery. RESULTS: A total of 20 patients had been referred to our center with visible signs of a GSH. The clinical examination showed atrophy of the abductor digiti minimi, abductor pollicis brevis, and interosseous musculature in all 20 patients. The ED assessments showed plexopathy of the lower brachial plexus in all the patients. HRUS showed an indented inferior trunk of the brachial plexus (so-called wedge-sickle sign) in 18 patients (90%). Of the 20 patients, 17 had undergone TOD surgery (15 transaxillary TOD and 2 supraclavicular TOD). Three patients had refrained from surgery. The median follow-up interval was 15.0 months (interquartile range, 14.0 months). The thoracic outlet syndrome disability scale score had improved significantly (preoperatively: mean, 6.31; 95% confidence interval [CI], 5.49-7.13; postoperatively: mean, 4.25; 95% CI, 2.80-5.70; P = .026). The same improvement was seen for the cervical brachial symptom questionnaire scores (preoperatively: mean, 77.75; 95% CI, 66.63-88.87; postoperatively: mean, 42.65; 95% CI, 24.77-60.77; P = .001) and disability of the arm, shoulder, and hand scale scores (preoperatively: mean, 59.13; 95% CI, 51.49-66.77; postoperatively: mean, 40.96; 95% CI, 24.41-57.51; P = .032). The NRS score for muscle weakness and sEAST score showed no statistically significant differences before and after TOD for the whole group (mean preoperative NRS score for muscle weakness, 6.22; 95% CI, 4.31-8.14; mean postoperative NRS score for muscle weakness, 5.11; 95% CI, 3.25-6.97; P = .269). However, four patients (23.52%) had reported a ≥50% decrease in the NRS score for muscle weakness and a minimum increase of 20% in the total and average force using the sEAST. The NRS for numbness showed a statistically significant decrease for the whole group (preoperatively: mean, 5.67; 95% CI, 4.18-7.16; postoperatively: mean, 3.33; 95% CI, 1.37-5.29; P = .029). CONCLUSIONS: A combination of physical examination, ED assessments, and HRUS studies can differentiate GSH in the differential diagnosis. HRUS appears to have an advantage over ED studies in confirming GSH by visualization of compression of the brachial plexus. TOD surgery will stop the progressive muscle atrophy and significantly reduce neurogenic thoracic outlet syndrome complaints, and, in some patients, motor function will recover.

Variability in electrodiagnostic findings associated with neurogenic thoracic outlet syndrome.

INTRODUCTION/AIMS: Neurogenic thoracic outlet syndrome (NTOS) is a heterogeneous and often disputed entity. An electrodiagnostic pattern of T1 > C8 axon involvement is considered characteristic for the diagnosis of NTOS. However, since the advent of high-resolution nerve ultrasound (US) imaging, we have encountered several patients with a proven entrapment of the lower brachial plexus who showed a different, variable electrodiagnostic pattern. METHODS: In this retrospective case series, 14 patients with an NTOS diagnosis with a verified source of compression of the lower brachial plexus and abnormal findings on their electrodiagnostic testing were included. Their medical records were reviewed to obtain clinical, imaging, and electrodiagnostic data. RESULTS: Seven patients showed results consistent with the "classic" T1 axon > C8 pattern of involvement. Less typical findings included equally severe involvement of T1 and C8 axons, more severe C8 involvement, pure motor abnormalities, neurogenic changes on needle electromyography in the flexor carpi radialis and biceps brachii muscles, and one patient with an abnormal sensory nerve action potential (SNAP) amplitude for the median sensory response recorded from the third digit. Patients with atypical findings on electrodiagnostic testing underwent nerve imaging more often compared to patients with classic findings (seven of seven patients vs. five of seven respectively), especially nerve ultrasound. DISCUSSION: When there is a clinical suspicion of NTOS, an electrodiagnostic finding other than the classic T1 > C8 pattern of involvement does not rule out the diagnosis. High resolution nerve imaging is valuable to diagnose additional patients with this treatable condition.