Neurinoma of the spinal accessory nerve: report of a case.

We report a patient with neurinoma of the spinal accessory nerve, who complained of intermittent occipital headaches, nausea, vomiting, blurred vision and unsteady gait. Neurological examination revealed papilledema, bilateral horizontal nystagmus and right cerebellar signs. Computed tomography revealed mild hydrocephalus, a low-attenuated lesion with a faint capsule after enhancement and partial compression of the 4th ventricle in the right posterior fossa. Vertebral angiography revealed no definite tumor vessels or stains. Under the impression of a posterior fossa tumor, a suboccipital craniectomy with a C1 and C2 laminectomy was performed. A 4 x 4 x 2.5 cm3 dumbbell tumor arising from the left spinal accessory nerve at the C2 level was found 4 x 4 x 2.5 cm3. The tumor extended upward through the foramen magnum with upward displacement of both tonsils to the right jugular foramen with slight adhesion to the right IX, X and XI cranial nerves. The left spinal accessory nerve was severed from the pedicle at the C2 level, and the tumor was totally removed. Diagnosis was made during the operation. The pathological examination showed neurinoma with cystic degeneration. During the following year, atrophy of the left sternocleidomastoid and trapezius muscles were noticed. Up to the time of this writing, there had been no clinical recurrence.