Schwannoma of the spinal accessory nerve.

The authors report a case of a schwannoma originating from the spinal root of the accessory nerve. The patient was a 40-year-old woman with chronic headache and blurred vision. A neurological examination failed to reveal any abnormal findings except for papilloedema. A computed tomographic (CT) scan showed hydrocephalus and a magnetic resonance image (MRI) on admission showed an enhancing extramedullary tumour located at the level of foramen magnum. The tumour was successfully removed and was verified to originate from the spinal root of the right accessory nerve. The hydrocephalus improved soon after surgery. The patient left hospital in a satisfactory condition. There are 15 cases of accessory nerve schwannomas reported in the literature; the authors report the 16th. Although accessory nerve schwannoma is very rare, one should consider it as one of the differential diagnoses for tumours at the foramen magnum.