To highlight a case of copper deficiency myeloneuropathy presenting with clinical and radiologic findings identical to vitamin B12 deficiency-related subacute combined degeneration (SCD) of the spinal cord.

Copper deficiency myelopathy is an uncommon but treatable metabolic disorder that produces dorsal column demyelination, resulting in gait ataxia, paresthesias, and spastic paraparesis - features indistinguishable from SCD due to vitamin B12 deficiency. Causes include prior gastrointestinal surgery, malabsorption, malnutrition, and excessive zinc exposure, which inhibits copper absorption. MRI typically demonstrates symmetric T2 hyperintensity within the dorsal columns of the cervical and thoracic cord, mirroring B12 deficiency. Prompt recognition is essential as delayed treatment may lead to irreversible neurologic damage.

A 71-year-old woman presented with progressive bilateral lower extremity weakness, gait instability, and sensory loss with a T6 level. Neurological exam revealed spastic paraparesis and impaired proprioception. MRI of the cervical and thoracic spine demonstrated confluent T2 hyperintensity in the dorsal columns without enhancement—findings suggestive of subacute combined degeneration. However, vitamin B12 and methylmalonic acid levels were normal. Further workup showed markedly low serum copper and ceruloplasmin levels, consistent with copper deficiency, likely secondary to chronic zinc-containing denture adhesive use and malnutrition. She received intravenous copper replacement for five days followed by oral copper therapy, resulting in stabilization and mild improvement in gait and sensation. She was discharged to acute rehabilitation for continued recovery.

Copper deficiency myelopathy is a rare yet reversible cause of dorsal column dysfunction that can closely mimic vitamin B12 deficiency both clinically and radiologically. Recognition of this mimicry is critical, as early copper repletion may halt or reverse neurologic progression. Serum copper and ceruloplasmin should be routinely evaluated in unexplained myelopathies with dorsal column MRI changes despite normal vitamin B12 levels.