The adult diplomyelia syndrome.

Diplomyelia is an uncommon variant of diastematomyelia in which the spinal cord remains divided caudal to the diastematomyelia spur. Presented here are three adults who presented with a sign-and-symptom complex that is likely to occur only when such an anatomic aberration is found. Each patient complained of pain and paresis in one leg. Neurologic examination demonstrated dysfunction of not only both long tracts but also lower motor modalities in the symptomatic leg and no abnormalities in the opposite leg. These findings, therefore, would strongly suggest that each leg was supplied by one of the split spinal cords, with only one cord being compromised. When planning surgical intervention on these patients, one must be aware that removal of the central spur alone may not resolve the problem because the spur, unlike that in diastematomyelia, does not tether the split spinal cords.