Cervical cord compression in hereditary multiple exostoses.

A seven year old girl, known to have hereditary multiple exostoses, developed moderate gait disorders at the age of six years. Deterioration of myelopathy initiated the clinical investigation including spinal computed tomography (CT) and magnetic resonance imaging (MRI). These examinations demonstrated a coneshaped exostosis originating from the posterior arch of C2. The spinal canal was markedly narrowed with significant compression of the spinal cord at the C2 level. The girl underwent laminectomy of C2 with total removal of the exostosis. Postoperative deterioration of neurological symptoms correlated with a hypointense lesion on T1 weighted imaging in the cord at the same level, but no further cord compression on follow-up MRI. The spastic tetraparesis has improved considerably within 12 months thereafter.