1112 - Assessment and Management of Newly Diagnosed Diastematomyelia in an Adult

Diastematomyelia (DSM) is a rare congenital spinal dysraphism in which the spinal cord splits into two hemicords separated by a bony, cartilaginous, or fibrous septum. Most cases are diagnosed in childhood; adult presentations are uncommon.

Case Description:

A young adult woman with kyphoscoliosis and a congenitally small right foot presented with progressive low back pain, right foot drop, and gait difficulty. She had minimal healthcare engagement since childhood. Lumbar MRI revealed DSM at L1–L2, and additional imaging suggested a second split at T4–T5. Neurosurgery deemed her high risk for surgery and referred her to pain management. As symptoms worsened, she was evaluated in our spinal cord clinic. Exam showed kyphoscoliosis with elevation of the left posterior superior iliac spine and scapula, along with right lower-extremity atrophy and weakness in ankle plantarflexion and dorsiflexion. She was referred to physical therapy, podiatry for ankle-foot-orthoses evaluation, and started on duloxetine for neuropathic pain and tamsulosin for urinary retention likely related to cord involvement.

Discussions:

DSM arises from abnormal embryogenesis in the third to fourth week, producing a midline septum that divides the cord. Two forms exist: Type I, with hemicords in separate dural sacs divided by a rigid spur, and Type II, with hemicords in one sac separated by a fibrous septum. Pediatric cases often present with scoliosis, cutaneous stigmata, or neurologic deficits. Adult cases (~20%) are uncommon and underrecognized. MRI is the diagnostic study of choice. Surgery is recommended for progressive deficits, but conservative care is appropriate when operative risk is high. Our case is notable for suspected dual splitting sites and demonstrates the role of multidisciplinary, non-surgical management.

Conclusions: This case illustrates a rare adult presentation of DSM with dual tethering sites. Clinicians should consider congenital malformations in adults with progressive neurologic decline and employ conservative strategies when surgery is not feasible.