Intellectual and motor functions in school children from severely iodine deficient region in Sikkim

High prevalence of endemic goitre (54%) and endemic cretinism (3.5%) exist in Sikkim. The level of intellectual functioning and motor performance were assessed in 90 school children in the age group of 10 to 12 years selected randomly from four severely iodine-deficient villages. Bender Visual Motor Gestalt Test, Binet-Kamat Test for mental ability and Raven's Coloured Progressive Matrices were the tests used. The results show an impairment in intellectual and other neuropsychological functions in a high percentage of the children. Visuomotor coordination was poor in 62 (69%). Binet-Kamat test results showed that 19 (21%) children were intellectually subnormal (IQ < 70). Majority of the children (> 80%) had significant impairment in language, meaningful memory, non-meaningful memory, conceptual thinking, numerical reasoning and motor skills. The children did better on non-verbal reasoning and social intelligence. Goitre was detected in 82 (91.1%). Urine samples for iodine estimations was collected from every second child examined. The mean urinary iodine concentration was 4.23 micrograms/dl (SD 2.16). Urinary iodine concentration was less than 2 micro gm/dl in 26.1% (11 children) and less than 5 micro gm/dl in 84.8% (39 children) indicating severe iodine deficiency. The test results show impairment of psychomotor development in children born and brought up in iodine-deficient environment.