Neuropathy caused by B12 deficiency in a patient with ileal tuberculosis: a case report

Vitamin B12 deficiency can result in macrocytic anemia. Neurologic abnormalities of B12 deficiency include sensory deficits, loss of deep tendon reflexes, movement disorders, neuropsychiatric changes and seizures. Segmental involvement of the distal ileum, such as in tuberculosis, can cause vitamin B12 deficiency. To our knowledge, macrocytic anemia with unusual manifestations such as brain atrophy and seizures due to intestinal tuberculosis has not been reported in the literature.

A 14-year-old girl presented with complaints of paraplegia, ataxia, fever and fatigue that had started a few months earlier and which had been getting worse in the last three weeks. Her laboratory results were indicative of macrocytic anemia with a serum B12 level <100 (normal, 160-970) pg/ml and hypersegmented neutrophils. Her MRI findings showed brain atrophy. Her fever workup eventually led to the diagnosis of tuberculosis which was documented by bone marrow aspiration smear & culture. A small bowel series showed that tuberculosis had typically involved the terminal ileum which had resulted in vitamin B12 deficiency. She was treated for vitamin B12 deficiency and tuberculosis. Her fever ceased and her hemoglobin level returned to normal. At present, she can eat, write, and speak normally as well as walk and ride a bicycle.

Vitamin B12 deficiency should be considered in patients with neurologic features such as paresthesia, sensory deficits, urinary incontinence, dysarthria, and ataxia. The underlying cause of B12 deficiency should be determined and treated to obviate the patients' need for long term vitamin B12 therapy.