Epidemiology of endemic cretinism in Sikkim, India.

A survey was conducted in Sikkim to determine the prevalence of endemic cretinism in the state. A household was the basic sampling unit. Villages were selected randomly in the state and from these households were selected randomly using the electoral lists. All members of the households were studied. Total of 17,837 individuals from 3,197 households from 249 villages were studied. There were 8,953 males and 8,884 females. A total of 617 endemic cretins were identified: 316 males and 301 females. The overall prevalence of endemic cretinism was 3.46%: (males 3.53% and females 3.39%). Endemic cretinism was observed in 194 (77.9%) villages studied. Neurological cretinism was the predominant form (98.7%). Deaf-mutism was the most salient neurological feature seen in 472 (76.5%) subjects. Motor system examination revealed proximal spasticity and brisk reflexes, both more marked in the lower limbs. Recording of daily life activities revealed 14.1% of the cretins to be totally dependent and another 23% to be requiring considerable assistance for their daily routine activities. The overall prevalence of goitre found in this survey was 54%. Urinary iodine concentration was estimated from a representative sample of the population; mean 4 micrograms/dl (SD 2.68). This survey shows the existence of severe iodine deficiency in Sikkim.

Clinical study of endemic cretinism in south Sikkim.

One hundred individuals suffering from Endemic Cretinism were studied. There were 55 males and 45 females. 62% of the cretins had visible goitre. Thirty nine (62.9%) goitrous cretins had grade II goitre. Neurological cretinism was the predominant type encountered (99%) and Myxoedematous cretinism was seen in only one patient. The most salient neurological feature was deaf-mutism seen in 74%. Findings in the motor system were, apart from deaf-mutism, the most characteristic feature of the condition on clinical examination. 58% had exaggerated deep tendon reflexes and 31% had extensor plantar response. Squint was noticed in 29%. Familial aggregation was noticed and was striking. Endemic cretinism is a distinctive and easily identifiable clinical entity and is an important indicator of the severity of iodine deficiency in a community.