1001 - Iatrogenic thoracic pseudomeningocele with syringomyelia and myelopathy

Case Diagnosis: Myelopathy due to a compressive iatrogenic thoracic pseudomeningocele with progressive syringomyelia

Case Description: 77 year-old right-handed female presented to PM&R Sports Medicine with progressive sensory loss in her feet and gait instability. She developed these symptoms following L4-L5 decompression and fusion in 2021 lumbar stenosis with cauda equina syndrome. Since surgery she noticed progressive numbness in her feet and ankles and feels unsteady when walking her dog or when going to the bathroom at night, and has tripped over her foot while walking. No focal lower extremity weakness or hyperreflexia was noted on examination. Lumbar MRI with progression of mild-to-moderate L3-L4 stenosis. She has chronic mild non-radiating mid back pain. Upon further discussion, she reported a remote history of thoracic meningioma resection in her 30s, and updated cervical and thoracic MRIs were obtained, showing a syrinx with a 7mm cavity extending from T3 to T6 and a posterior fluid collection concerning for a pseudomeningocele. No cervical stenosis was seen.

Discussions: This is a 77-year-old woman with a remote history of thoracic meningioma resection and recent L4-5 decompression and fusion who presents with symptoms concerning for progressive myelopathy. MRI shows a large syrinx in the thoracic spine. This may have progressed due to compression from an iatrogenic pseudomeningocele related to prior thoracic decompression. The syrinx can cause compression of the spinal cord and damage to the nerves, leading to symptoms such as numbness, weakness, pain or gait instability. Surgical and nonsurgical interventions (anti-inflammatory medications and physical therapy) may improve symptoms, but prognosis is guarded as spinal cord compression may progress.

Conclusions: This is a rare case of progressive syringomyelia presenting with myelopathy secondary to a suspected iatrogenic pseudomeningocele in the setting of remote thoracic meningioma resection. Neurosurgery was consulted for further evaluation and management. Treatment and symptom management to follow.