We report a case of posterior spinal artery (PSA) infarct initially misdiagnosed as transverse myelitis (TM) and highlight some of the differentiating features of this exceedingly rare entity.

Spinal cord infarcts (SCIs) represent 1% of strokes and 5-8% of acute myelopathy. In a systematic review of 133 cases of SCI collected over two decades, PSAs presented 11% of the total pool. Redundancy in the vascular supply of the posterior portion of the spinal cord accounts for PSA rarity. 

A single case report.

A 62-year-old woman with a history of recurrent nephrolithiasis, vitamin B12 deficiency, hypertension, and hyperlipidemia presented painless and rapidly progressive severe numbness and weakness of the legs. Sphincter symptoms were absent. Enhanced Magnetic Resonance Imaging (MRI) of the brain and spinal cord were unremarkable. Cerebral spinal fluid (CSF) was unremarkable.  She was diagnosed with TM, given a five-day course of intravenous (IV) steroids, and discharged to a rehabilitation facility with a protracted and incomplete recovery. She presented two years later with fluctuating sensory and motor symptoms in the context of ureteral stent removal. Repeat CSF was unremarkable. However, on repeat thoracic spine MRI, there was interval development of a T2 hyperintensity along the dorsal columns and myelomalacia from T3-T4 disc to T12. She received IV steroids with minimal improvement. She had recurrent myelopathy pseudoexacerbations in the context of concurrent illnesses subsequently. Spinal magnetic resonance angiography, computerized chest, abdomen, pelvis tomography, positron emission tomography scan, and cardiovascular investigations were unremarkable.