Focal Diastematomyelia in an Adult: A Case Report

Diastematomyelia (DSM) is a rare congenital malformation that splits the spinal cord longitudinally into two by either cartilage, bone, or fibrous septum. There are multiple case reports of DSM in the pediatric population, but only a few cases of DSM in adult patients have been reported in the literature. This case report describes a middle-aged female patient who presented to the hospital with progressive worsening bilateral proximal lower extremity weakness. A neurological exam was significant for effort-dependent bilateral proximal lower extremity weakness. In addition, magnetic resonance imaging was consistent with an incidental finding of a focal structural-developmental anomaly of diastematomyelia at the distal conus medullaris of the spinal cord vertebral level L2-L3. Following no acute imaging or laboratory abnormalities, the patient was treated with pain management, physical therapy, and outpatient follow-up care. Even though there are multiple differential diagnoses of bilateral lower extremity weakness in adult patients, diastematomyelia malformation is rarely diagnosed in this age group. Therefore, knowledge of this rare congenital anomaly in adult patients should be familiar to interpreting radiologists and treating clinicians.