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Introduction: NVBD is a common cause of neurological dysfunction in infants. Neuroimaging findings have been described in small series of patients only.

Methods: Diagnosis of NVBD was made on the basis of clinical presentation, macrocytosis, and low serum vitamin B₁₂. In children with prior treatment with vitamin B₁₂, low maternal serum vitamin B₁₂ indicated NVBD in the infants. Neuroimaging findings were extracted from the patient charts.

Results: 31 infants, 21 boys and 10 girls, and aged between 6 months to 27 months (mean age 13.2months) with NVBD who had undergone at least one neuroimaging study (CT or MRI) were included. All had developmental delay, 30 had developmental regression, and 22 tremors at presentation. Skin hyperpigmentation and hair changes were noted in 30 infants each. Anemia was present in 19 and macrocytosis in 22, and low serum vitamin B₁₂ in 14. Seventeen of the 18 mothers also had low serum vitamin B₁₂. Of the 10 infants with normal serum B1₂, 8 had macrocytosis and/or low maternal serum vitamin B₁₂. Brain CT available in 5 infants showed diffuse cerebral atrophy in all. Brain MRI available in 26 infants showed moderate to severe diffuse cerebral atrophy. Delayed myelination was present in 8. One child each showed subdural effusions and bilateral BG hyperintensities with diffusion restriction.

Conclusions: In NVBD, diffuse cerebral atrophy is the most frequent neuroimaging findings followed by delayed myelination. Basal ganglia involvement is being described for the first time.      

 

nutritional vitamin B12 deficiency; infants; neuroimaging; cerebral atrophy; delayed myelination