Vitamin B12 Deficiency as a Cause of Delirium in a Patient With Spinal Cord Injury

A man with spinal cord injury (SCI) and multiple medical comorbidities had new-onset delirium during his 14th month of hospitalization. Diagnostic workup did not elicit an obvious etiology for mental status changes. Delirium persisted despite psychiatry intervention, and he was unable to be weaned from the ventilator because of prolonged agitation. Routine anemia workup revealed a possible untreated vitamin B12 deficiency, although laboratory values were inconclusive. Empiric treatment with cyanocobalamin injections was initiated, and his delirium remarkably resolved after 3 weeks of treatment. We provide a concise review of the etiologies and varied clinical presentations of vitamin B12 deficiency. As illustrated in this case, classic laboratory findings may not appear, and neurologic impairments from SCI can obscure the physical signs of deficiency, making diagnosis difficult. Empiric treatment may be indicated in cases of neuropsychiatric abnormalities not explained by other causes.