408 - Arachnoiditis Ossificans Causing Progressive Weakness in a Young Adult with Spina Bifida

Case Diagnosis: Arachnoiditis Ossificans Causing Progressive Weakness in a Young Adult with Spina Bifida

Case Description: A 20-year-old male with a known history of low-lumbar myelomeningocele and neuromuscular scoliosis requiring spinal fusion presented to the clinic with complaints of slowly progressive weakness in the left leg and impaired endurance. He previously used forearm crutches for community mobility, but in the prior 6 months, he began experiencing leg buckling and falls, which was new for him. He required use of a walker with a seat for rest breaks, and ultimately began using his wheelchair more often. He underwent MRI and CT of the thoracic and lumbar spine, which revealed a peri-circumferential calcification of the spinal cord from T10 to L4, with worsened findings on the left side of the spinal cord. He was diagnosed with arachnoid calcification, a rare and insidious condition which can cause myelopathy or radiculopathy, along with loss of lower extremity function.

Discussions: This case is the first of its kind in a patient with known history of spina bifida. Arachnoiditis ossificans is typically caused by trauma, previous subarachnoid hemorrhage, spinal anesthetics, and myelograms. A patient with spina bifida certainly meets each of these criteria, however, this unusual diagnosis has not yet been published.

Conclusions: While patients with spina bifida are at high risk of progressively changing spinal cord abnormalities, such as a syrinx, other considerations and imaging modalities may be required to properly identify the underlying cause of weakness in patients with unreliable initial exams.