Benign tumors of the foramen magnum.

The authors reviewed 102 documented cases of benign extramedullary tumors of the foramen magnum treated at their institution between 1924 and 1982. There was 78 meningiomas, 23 neurofibromas, and one teratoma. Approximately 40% of the patients had a normal neurological examination upon first evaluation. The most frequent presenting complaints were suboccipital neck pain, dysesthesias, gait disturbances, weakness, and hand clumsiness. The average time from initial symptoms to diagnosis was 2 1/4 years. The most common findings included hyperreflexia, arm or hand weakness, Babinski sign, spastic gait, sensory loss, and 11th cranial nerve involvement. Based on these cases, an attempt is made to distinguish foramen magnum tumors from other disease entities by a grouping of signs and symptoms. There is no clinical finding that is pathognomonic. Metrizamide computerized tomography scanning and Pantopaque myelography have been the radiographic tests most commonly used to evaluate the foramen magnum. Recent experience suggests that nuclear magnetic resonance scanning will be a very useful noninvasive means of evaluating the foramen magnum region.