When two becomes one: neurological manifestation of vitamin B12 deficiency

Vitamin B12 deficiency has a wide spectrum of clinical presentation with a variety of neurological symptoms and signs. Early diagnosis and treatment are crucial to prevent the irreversible damage to the nervous system. We present a case report of a 72-year-old woman with 2 weeks history of progressive bilateral hand and feet numbness followed by paresthesia with subsequent development of weakness, and ataxia accompanied with weight loss, vomitus, and diarrhea. The neurological assessment revealed glove and-stocking paresthesia with impaired joint position and vibration sensation in toes and fingers and hyperreflexia. Full blood count revealed macrocytic anemia. Further study showed severe vitamin B12 deficiency and positive for autoantibodies against intrinsic factor and parietal cells. Gastroscopy showed gastric mucosa atrophy with compatible biopsy results. Magnetic resonance imaging (MRI) of the spine revealed an increased T2-weighted signal in the posterior columns of cervical spinal cord, extending from C1 to C7 level, without any gadolinium enhancement on T1-weighted contrast images. These findings were consistent with subacute combined degeneration and autoimmune gastritis with pernicious anemia. Clinical improvement occurred over the ensuing months with parenteral B12 therapy. Neurological symptoms in vitamin B12 deficiency are frequent. Early spinal MR imaging assists in the early diagnosis and treatment.