Klippel-Feil syndrome presenting with bilateral thoracic outlet syndrome

Study Design. This report aims, in the light of the recent literature, to describe the clinical features of bilateral thoracic outlet syndrome in a case of Klippel-Feil syndrome, the results of electrophysiologic evaluation, and the outcome after surgical intervention. Objectives. Cervical ribs in the context of Klippel-Feil syndrome as the cause of bilateral thoracic outlet syndrome is discussed. Summary of Background Data. In Klippel-Feil syndrome, congenital fusion of cervical vertebrae occurs and may also be associated with various anomalies, including musculoskeletal anomalies. The typical neurologic defects in this syndrome are caused by compression of the cervical cord and/or the corresponding roots. Methods. A 25-year-old woman had experienced, for 3 years, sensory symptoms, mainly numbness and pain, in both arms and episodic color changes of the hands that were aggravated by certain activities. Results. Radiologic examination revealed Klippel-Feil syndrome type I, accompanied by bilateral cervical ribs. Electrophysiologic evaluation demonstrated impairment of nerve conduction, as indicated by F wave changes, after the arms were raised. The patient underwent successful decompression of the neurovascular structures at the thoracic aperture. Conclusions. It is often difficult to diagnose thoracic outlet syndrome by conventional neurophysiology. Dynamic changes in F waves appear to be a useful finding. In the absence of symptoms of myeloradiculopathy, thoracic outlet syndrome could be the sole manifestation of Klippel-Feil syndrome.