Subacute combined degeneration of spinal cord, optic atrophy and thrombocytopenia without anemia secondary to B12 deficiency

Long-standing vitamin B12 deficiency can lead to neurological manifestations such as optic atrophy and subacute combined degeneration of the cord without causing significant anemia. In addition, folic acid supplementation could mask the hematological manifestations of vitamin B12 deficiency and delay the presentation of neurological manifestations

We present a case of a 32-year-old vegan woman on long-term sodium valproate and folic acid treatment presenting with progressive weakness of bilateral lower limbs for three months and reduced vision in both eyes for two weeks duration. Further evaluation revealed optic atrophy, combined degeneration of the spinal cord, macrocytosis, thrombocytopenia, and severely deficient serum B12 levels. With B12 replacement therapy, the patient’s overall wellbeing improved.