[Occipital neuralgia caused by the compression of the fenestrated vertebral artery: a case report].

A case is presented of fenestration of the vertebral artery in a 36-year-old woman who had various neurological symptoms with Basedow's disease. We also review 7 cases from the literature. Our patient had had occipital neuralgia and numbness of the left side of the neck and left upper limb several weeks before admission. On admission she had hyperthyroidism. MRI, left vertebral angiography, and 3D-CT scans demonstrated a fenestrated vertebral artery compressing the upper cervical cord. The patient's symptoms gradually improved as her thyroid function was controlled. A possible explanation is that the fenestrated vertebral artery might have compressed the neural structures, resulting in her various symptoms. Occipital neuralgia was apparently caused by the fenestrated artery compressing the C1 and C2 sensory roots. A fenestrated vertebral artery is usually of no clinical significance. The reason for the late onset of symptoms in the present case is unknown, but it may have been due to hemodynamic stress caused by her hyperthyroidism. After her thyroid function was controlled, the hemodynamic stress presumably decreased and the symptoms resolved spontaneously.