Coma and respiratory failure in a child with severe vitamin B12 deficiency

Objective: Psychofunctional follow-up of severe vitamin B₁₂ deficit. Design: Case report. Setting: Pediatric intensive care unit. Patient: Ten-month-old boy. Intervention: Follow-up at 3 yrs. Measurements and Main Results: A 10-month-old boy was admitted to the pediatric intensive care unit with respiratory failure, muscular hypotonia, and involuntary movements. Although a central nervous system infection was excluded, computed tomography scan showed a diffuse cortical-subcortical atrophy. Vitamin B₁₂ deficiency was suspected because of a red-cell count of 1,350,000/mm³ and a hemoglobin value 5.9 g/dL (MCV 116). The baby had been exclusively breast-fed, but his mother had been a strict vegan for 10 yrs. Chronic dietary vitamin B₁₂ deprivation was confirmed by blood and urinary samples. Treatment with vitamin B₁₂ led in 2 wks to rapid and complete hematological improvement and to partial regression of neurologic symptoms. During the following 3 yrs the boy had normal vitamin intake and underwent intensive rehabilitative treatment. The brain atrophy regressed, but linguistic and psychomotor delay persisted. Conclusions: Rapid clinical improvement after vitamin supply does not correlate with a complete recovery.