Syncope caused by congenital anomaly at the craniovertebral junction: a case report

INTRODUCTION: Anomalies in the craniovertebral junction may be a rare cause of syncope. The mechanisms of syncope related to craniovertebral junction anomaly remain unknown. We present an extremely rare case with anomaly in the craniovertebral junction and syncope, and discuss the mechanism of the syncope. CASE PRESENTATION: A 10-year-old Japanese boy with a congenital anomaly in the craniovertebral junction presented with recurrent syncope. A physical examination showed generalized hyperreflexia, but motor and sensory examinations were normal. Computed tomography and magnetic resonance imaging showed basilar invagination and spinal cord compression at his craniovertebral junction. Three-dimensional computed tomography angiography revealed an anomalous course of his bilateral vertebral arteries, both of which showed a persistent first intersegmental artery that entered the spinal canal at the caudal portion of the C1 posterior arch. In this case, the arteries were nearly pinched between the C1 posterior arch and the pars interarticularis of the C2. C1 laminectomy and occiput-cervical fusion (O-C2) was performed using an instrumentation system. After surgery, the syncope was not observed. CONCLUSIONS: Syncope can be related to compression of extracranial arteries within the neck. In this case, transient brain ischemia caused by the anomalous course of vertebral arteries that were pinched between the C1 posterior arch and the pars interarticularis of C2 in cervical motion was the suspected cause of the syncope.