Neurogenic thoracic outlet syndrome due to subclavius posticus muscle with dynamic brachial plexus compression: a case report.

Julia Muellner,Oliver Pfeiffer,Alain Kaelin-Lang,Marwan Mohamed El-Koussy

doi:10.1186/s13104-015-1317-3

Julia Muellner, Oliver Pfeiffer + Show 2 more

Open Access

https://doi.org/10.1186/s13104-015-1317-3

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Abstract

BackgroundNeurogenic thoracic outlet syndrome is an underestimated cause of brachial weakness and pain. The subclavius posticus muscle (SPM) is an aberrant muscle originating from the medial aspect of the first rib reaching to superior border of the scapula, which may cause, depending on its activation, dynamic compression of the brachial plexus.Case presentationIn the present study, we report about a 32-year-old male caucasian patient with weakness in radial deviation of his left hand. An isolated macrodactyly of his left middle finger had been operated twice. Electroneurography showed a carpal-tunnel-syndrome (CTS) on the left side. MRI of the brachial plexus revealed an additional muscle in the costoclavicular space, identified as SPM. To our knowledge, this is the second case report of a neurogenic thoracic outlet syndrome due to SPM, and the first case described with isolated macrodactyly and CTS in the same patient.ConclusionIf complaints about hand weakness are only reported in cases of distinct hand positions, a dynamic compression of the brachial plexus by SPM may be the cause. A neurogenic thoracic outlet syndrome may facilitate the development of CTS.

Highlights

Neurogenic thoracic outlet syndrome is an underestimated cause of brachial weakness and pain
If complaints about hand weakness are only reported in cases of distinct hand positions, a dynamic compression of the brachial plexus by subclavius posticus muscle (SPM) may be the cause
A neurogenic thoracic outlet syndrome may facilitate the development of CTS

Summary

Conclusion

This case illustrates that SPM is a rare, but probably underestimated cause of NTOS. Its presence may enable the occurrence of CTS [4] as well. Consent Written informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal. The consent form signed by the patient is in accordance with the BMC research guidelines. Authors’ contributions Primary involved physicians and writers of the case report: JM, AK-L. Involved neuroradiologists who provided the presented image and its explanations: OP, MME-K. All authors read and approved the final manuscript. Author details 1 Department of Neurology, University Hospital Bern, Freiburgstrasse 100, 3010 Bern, Switzerland. 3 Department of Neuroradi‐ ology, University Hospital Bern, Bern, Switzerland

Background

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