Diagnosing neurogenic thoracic outlet syndrome with the triple stimulation technique. Issue 1 (January 2016)

• Record Type: Journal Article
• Authors: Feng, Jun-Tao; Zhu, Yi; Hua, Xu-Yun; Zhu, Yu; Gu, Yu-Dong; Xu, Jian-Guang; Xu, Wen-Dong
• Is Part Of: Clinical neurophysiology. Volume 127:Issue 1(2016:Jan.)
• Page Start: 886
• Page End: 891
• Publication Date: 2016-01
• Subjects: Triple stimulation technique -- Neurogenic thoracic outlet syndrome -- Central motor-conduction time -- Conduction block; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2015.04.065
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: The triple stimulation technique (TST) was assessed in the diagnosis of neurogenic thoracic outlet syndrome (TOS). By combining the TST amplitude ratio and the central motor-conduction time, the compression site of neurogenic TOS can be located. The decreased amplitude ratio revealed the existence of conduction block in neurogenic TOS besides axonal loss. Abstract: Objective: We assessed the diagnostic value of triple stimulation technique (TST) in eight patients with neurogenic thoracic outlet syndrome (TOS) by revealing the conduction block of the proximal lower trunk of the brachial plexus and locating the compression site. Methods: Eight patients fulfilling the conventional criteria of the lower-trunk neurogenic TOS were enrolled in our study. TST along with the central motor-conduction time was evaluated. The parameters including the TST amplitude ratio and the TST area ratio were compared between patients and controls. Results: The amplitude ratio was significantly lower in the patient group than in the control group (patients: 0.518 ± 0.113; control: 0.954 ± 0.020, P < 0.01), so was the area ratio (patients: 0.453 ± 0.194; control group: 0.955 ± 0.192, P < 0.01). No significant difference of central motor-conduction time (CMCT) was seen between the patient group and the control group (patients: 6.62 ± 0.36 ms; control: 6.54 ± 0.36 ms; P = 0.528). Surgical procedures proved the compression of the lower trunk in all patients. Conclusion: Our results indicated that there was conduction block besides axon loss in neurogenic TOS patients, and the conduction block was located between the nerve root emerging site and the supraclavicular stimulation site. Significance: We first applied TST in diagnosing neurogenic TOS, and we showed that the patient's TST ratio was significantly lower than normal. Combined with clinical manifestations, TOS can be more precisely diagnosed.