A Rare Case of Folate Deficiency-Induced Subacute Combined Degeneration of the Spinal Cord: A Case Report.

Folate deficiency is a rare cause of subacute combined degeneration (SCD). SCD is characterized by demyelination of the dorsal and lateral columns of the cervical and thoracic spine most commonly caused by vitamin B12 deficiency. Folate deficiency, which can be clinically indistinguishable from B12 deficiency, leads to a variety of presentations, including absent vibratory sensation and proprioception, sensory ataxia, and progressive motor weakness. Recognizing the clinical sequelae of SCD is essential for timely diagnosis and treatment. We present a case of a 38-year-old male with progressive ascending bilateral lower extremity numbness and motor weakness in the presence of normal vitamin B12 and methylmalonic acid levels. MRI of the entire neuraxis revealed a diagnosis of SCD, which was managed with oral folate replacement. We aim to highlight this rare cause of SCD, which can lead to permanent neurological deficits if not promptly recognized and treated.