Progressive Myelopathy With Acute Worsening After Steroids and Lumbar Puncture.

We present the case of a 73-year-old woman with a 3-month history of non-traumatic thoracic myelopathy. Initial MRI showed a T6-conus T2 signal hyperintensity. Based on this presentation, and given a personal and family history of autoimmune disease, our patient was first managed as an inflammatory transverse myelitis. Subsequent worsening after lumbar puncture and steroids prompted re-evaluation, ultimately identifying the cause as a thoracic spinal dural AV fistula. Both investigation of possible transverse myelitis with lumbar puncture and empiric treatment with steroids may not only result in diagnostic delays but also precipitate venous infarction and irreversible harm. While the MRI often provides the initial diagnosis, clinical suspicion for this under-diagnosed cause of myelopathy should be raised in older patients with a more progressive thoracic myelopathy with worsening after lumbar puncture and/or steroids. Definitive and time-sensitive treatment by interventional neuroradiology or neurosurgery results in stabilization or improvement of disability in most cases.