Neuroma of the spinal accessory nerve disclosed by a subarachnoid hemorrhage: case report

Neuroma of the 11th nerve disclosed by subarachnoid bleeding is a very rare condition. Clinical diagnosis is almost impossible, but previous episodes of muscle spasm and mild signs of subarachnoid hemorrhage with a hematoma in the cisterna magna should suggest magnetic resonance imaging as well as angiography.

We present a case of an 11th nerve neuroma disclosed by subarachnoid bleeding. Previous episodes of muscle spasm and neck pain treated with nonsteroid anti-inflammatory drugs had been overlooked, preventing the neuroma from being diagnosed at that time. The computed tomographic scan showed an intracisternal hematoma spreading into the subarachnoid space. The hematoma appeared heterogeneous on the magnetic resonance image, and a tumor mass growing into the cisterna magna against the brain stem was also revealed.

The tumor was totally removed by a suboccipital craniectomy and C1 laminectomy. It originated from the spinal root of the 11th nerve, from which it was able to be dissected without damage to the nerve.

To our knowledge, this is the first reported case of an 11th nerve neuroma disclosed by a subarachnoid hemorrhage. Furthermore, this is the seventh documented case of an 11th nerve neuroma developing in the cisterna magna. We emphasize the importance of a high index of suspicion for the rare instances of hematic density limited to the cisterna magna, especially if associated with recurring episodes of localized neck pain and muscle spasm treated with nonsteroid anti-inflammatory drugs.