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Indian Pediatr 2016;53: 173-174 |
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Infantile Tremor Syndrome: A Syndrome in
Search of its Etiology
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* Jatinder S Goraya and
#Sukhjot Kaur
From Departments of Pediatrics and #Dermatology,
Dayanand Medical College and Hospital, Ludhiana, Punjab, India.
Email: * [email protected]
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Indian Pediatrics has done a great service by revisiting ‘Infantile
Tremor Syndrome’ (ITS) [1]. Even though, ITS has existed for almost 60
years, it continues to be perceived as a syndrome of unknown etiology.
However, there is now enough epidemiological, clinical, laboratory and
therapeutic evidence in the literature to support vitamin B 12
deficiency as the cause of ITS.
Epidemiologically, ITS occurs in exclusively
breastfed infants of strictly vegetarian mothers. As a result, these
infants are predisposed to develop vitamin B 12
deficiency. Clinically, symptoms and signs of ITS are similar to those
of vitamin B12 deficiency in
infants. Many studies in the past excluded vitamin B12
deficiency in ITS on the basis of mere absence of macrocytosis or
megaloblastic bone marrow. Absence of these features does not exclude
the diagnosis of vitamin B12
deficiency which requires serum vitamin B12
measurement. Several studies [2-4] have consistently demonstrated low
serum vitamin B12 in these
infants. Study by Bajpai, et al. [5] is the only report to have
found normal serum vitamin B12,
but only 20 (15%) of 134 infants were tested in this
series. Additionally, in some studies from India, infants with
megaloblastic anemia due to vitamin B12
deficiency displayed symptoms and signs consistent with ITS [5]. In one
such study [9] of 52 infants with megaloblastic anemia, pallor was
present in 96%, skin hyperpig-mentation in 77%, developmental delay in
67%, and 43% had hypotonia.
Response to treatment with vitamin B 12
in ITS is rapid with improvement in general activity and responsiveness
within 48-72 hours. This is followed by the return of social smile and
improved appetite. Lost developmental milestones are gradually regained.
The tremors begin to subside by the end of first week and disappear
completely by 3-4 weeks [2,3]. It follows that infants with vitamin B12
deficiency can present with predominantly hematological (megaloblastic
anemia) or predominantly neurological (infantile tremor syndrome)
manifestations. Some infants may have purely neurological or purely
hematological presentations. Most importantly, evidence of vitamin B12
deficiency has been found wherever it has been adequately looked for. It
is, therefore, time to discard the syndrome status for this disorder,
and rename it as ‘nutritional vitamin B12
deficiency in infants’ as it is known elsewhere in the world.
References
1. Mukherjee SB. Infantile tremor syndrome – A tale
of 50 years. Indian Pediatr. 2015;52: 599-600.
2. Goraya JS, Kaur S. Infantile tremor syndrome: Down
but not out. Indian Pediatr. 2015;52:249-50.
3. Jain R, Singh A, Mittal M, Talukdar B. Vitamin B12
deficiency in children: A treatable cause of neurodevelopmental delay. J
Child Neurol. 2015;30:641-3.
4. Bajpai PC, Misra PK, Tandon PN. Further
observations on infantile tremor syndrome. Indian Pediatr. 1968;5:
297-307.
5. Mittal VS, Agarwal KN, Observations on nutritional megaloblastic
anemia of early infancy. Indian J Med Res. 1969;57:730-8.
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