Involuntary Movements and Magnetic Resonance Imaging Findings in Infantile Cobalamine (Vitamin B₁₂) Deficiency

Infantile vitamin B₁₂ (vit B₁₂) deficiency is encountered in malnourished infants or in offspring of strict vegan mothers or mothers with pernicious anemia and accompanied by hematologic and neurologic findings. We present here a 16-month-old infant whose mother had vit B₁₂ deficiency with low socioeconomic level admitted to our hospital. On admission, the patient was apathic, hypotonic, and lethargic. Serum vit B₁₂ level was below detectable limits. On cranial magnetic resonance imaging (MRI), T2-weighted images revealed bilateral frontal and parietal periventricular high-signal symmetric lesions in the white matter (delayed myelination) and frontoparietal cortical atrophy. On day 3 of vit B₁₂ therapy, involuntary movements were observed.

Vit B₁₂ is an essential vitamin and needs to be supplied by diet. Although a vit B₁₂-deficient diet can be tolerated by the adults for years from the endogenous pool, deficiency in infants may become symptomatic in a few months because of the limited hepatic reserve.¹ Infantile vit B₁₂ deficiency is common in malnourished offspring of vegan mothers and mothers with pernicious anemia and has a clinical course of ineffective hematopoiesis and neurodegenerative signs.^1–5 Here, we present a 16-month-old male infant who had severe vit B₁₂ deficiency accompanied by hematologic, neurologic, and typical MRI findings.

Reprint requests to (Z.A.) Department of Pediatrics, Fatih University School of Medicine, Alparslan Türkeþ cad. No: 57, 06510, Beþtepe, Ankara, Turkey. E-mail: zekaiavci{at}yahoo.com