A previously normal, 15-month-old boy, born at term to nonconsanguineous parents, was hospitalized for generalized tremors for 3 days. Child was unable to cry and feed. He was exclusively breast fed. He was classified as grade 2 (IAP) malnutrition; he also had hyperpigmentation over limbs, pallor and hepatosplenomegaly. Tremors were absent during sleep, and got aggravated during activities (Web Video 1). His hemoglobin was 5.8 g/dL with dimorphic blood picture. EEG was normal and MRI showed diffuse cerebral atrophy. Mother’s serum B12 levels were low (<200 pg/mL) but child’s serum B12 levels were normal, probably because of prior treatment with injectable B12. A diagnosis of Infantile tremor syndrome (ITS) was made. Child received WHO protocol of management for moderate malnutrition. The child received blood transfusion, vitamin (A, D, B complex and C) and mineral (zinc, magnesium, calcium) supplementation. Propranolol (0.5 mg/kg/day) was started, and increased to 2 mg/kg/day till the tremor decreased in intensity and general condition of child improved. Kahn’s nutritional recovery syndrome, infections (viral encephalitis/encephalopathy), phenothiazine toxicity, degenerative diseases, and enzyme defects in tyrosine metabolism leading to substantia nigra depigmentation are the differential diagnoses of ITS.

Web Video 1 Infant with characteristic tremors suggestive of Infantile Tremor Syndrome.

Infantile tremors are unique in that they are present only in awake state. Tremors are fast (7Hz) and coarse, and involve distal part of limb, especially head face and tongue. Infants with ITS have difficulty in speech and produce sound like bleating of goat. They may also toss the head from side-to-side.