Treatable extramedullary cord compression. Meningioma as a cause of the Brown-Séquard syndrome.

The Brown-Séquard syndrome is infrequently reported. Though widely considered indicative of intramedullary spinal cord disease, in the absence of penetrating spinal cord trauma, the syndrome is frequently an early stage of extramedullary spinal cord compression, as an extensive analysis of diverse literatures reveals. We describe two cases resulting from compression of the spinal cord by a meningioma. While previous reviews emphasize that radicular or vertebral pain is a prominent feature of spinal cord compression by intradural tumors, our patients had no pain referable to tumor. Awareness that painless extramedullary spinal cord compression can produce the Brown-Séquard syndrome, early myelography, and surgical intervention are necessary to prevent progressive deficit. Even when encountered in a patient who has previously well-documented demyelinating disease, the syndrome should not be written off as a relatively untreatable intramedullary process.