Neurology of Nutritional Vitamin B₁₂Deficiency in Infants

Abstract

We studied 27 infants aged 6 to 27 months with vitamin B12 deficiency also known as "infantile tremor syndrome" in India. All were exclusively breast-fed by vegetarian mothers. Developmental delay or regression, pallor, skin hyperpigmentation, and sparse brown hair were present in all. Majority were hypotonic and involuntary movements were encountered in 18. Anemia and macrocytosis was found in 83% and 71% infants, respectively. Low serum vitamin B12 was present in 12 of 21 infants. Seven of the 9 infants with normal serum vitamin B12 had received vitamin B12 before referral. Twelve mothers had low serum vitamin B12. Cerebral atrophy was present in all the 9 infants who underwent neuroimaging. Treatment with vitamin B12 resulted in dramatic improvement in general activity and appetite within 48 to 72 hours followed by return of lost milestones. Tremors resolved in all by 3 to 4 weeks. Nutritional vitamin B12 deficiency is a treatable cause of neurologic dysfunction in infants.

Tyrosine hydroxylase deficiency—Clinical insights and a novel deletion in TH gene in an Indian patient

“…The present case was initially thought to be a vitamin B12‐deficiency related infantile tremor syndrome, but was further investigated after no response to vitamin B12 was noted. The infantile tremor syndrome is a well‐known entity in the Indian scenario, even today . The present case was confirmed to have TH deficiency only after definitive neurotransmitter analysis and genetic testing.…”

Cerebral atrophy in 21 hypotonic infants with severe vitamin B12 deficiency

“…Irregularities in myelin formation as a result of irregular coupling of fatty acids, as well as increased lactate and neurotoxic cytokines, disrupt myelin formation, which is most active in the first 6 months of life. After B12 treatment, abnormal movements such as tremors or myoclonus might be seen for 10–30 days . Although this treatment does not affect morphological changes at first, it can correct neurotransmitter imbalance and related pathologies …”

Vitamin B12 deficiency as a cause of severe neurological symptoms in breast fed infant – a case report

“…Case studies described in the literature clearly indicate that vitamin B 12 levels should be considered during differential diagnosis of neurological symptoms in infants, especially if they co-exist with megaloblastic anemia and psychomotor retardation [1,[3][4][5][6]24]. The most crucial factors for long-term prognosis are early diagnosis and early onset of treatment, as the duration of deficiency may be correlated with the development of long lasting changes in the nervous system [4,24].…”

“…Megaloblastic anemia coexisting with neurological symptoms may indicate a deficiency related cause with primary focus given to folic acid deficiency [1,2]. When such symptoms are observed it is important to extend the diagnosis and verify vitamin B 12 levels as its deficiency may affect especially those infants who are fed exclusively with breast milk [2,3]. Vitamin B 12 therapy results in instant improvement while longterm deficiency may cause permanent damage to the nervous system [4].…”