Abstract
The neuropsychological performance of schoolchildren living in areas with present and past iodine deficiency in Tuscany was investigated. Children were submitted to: a) block design subtest of the Wechsler Intelligence Scale for Children-Revised (WISC-R) and a modified version of the WISC-R coding subtest which evaluate the general neuropsychological and cognitive performance, independently from familial cultural background; b) simple reaction time (RT) session which evaluates the efficiency of the whole information processing and nervous transmission mechanisms. Neuropsychological performance was tested in 107 children living in Borgo a Mozzano, an area of mild iodine deficiency (IDA) with a median urinary iodine excretion (UIE) of 64 μg/L (mean±SD: 80.1±57). One hundred and six sex and age-matched children living in Marina di Pisa, an iodine sufficient coastal village of Tuscany (ISA) with a median UIE of 142 μg/L (mean±SD: 173±95) were used as controls. Tests for neuropsychological performance were performed in 57 children living in the village of Vagli, an area with past iodine deficiency (PIDA): 30 children born before iodine prophylaxis (Group 1), when the median UIE was 32 μg/L (mean±SD: 47±22), 27 children born after the institution of iodine prophylaxis (Group 2), when the median UIE was 109 μg/L (mean±SD:130±73). Sex and age-matched ISA-children were used as controls for each group. RTs were significantly delayed (p<0.05) in IDA than in ISA children, while block design and coding subtests showed no significant difference. PI-DA children of Group 1, but not those of Group 2 showed significantly delayed RTs when compared to controls, block design and coding tests being unaffected. In conclusion, our data indicate that: i) mild iodine deficiency may impair the rate of motor response to perceptive stimuli, as assessed by measurement of reaction time, in the absence of general cognitive impairment; ii) the effects of exposure to iodine deficiency during fetal/neonatal life, in spite of correction in the early childhood, may persist longer. Our findings also suggest that the measurement of simple RTs is a sensitive test to detect subtle neurological damages in mild iodine deficiency.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bleichrodt N., Drenth P.J.D., Querido A. Effects of iodine deficiency on mental and psychomotor abilities. Am. J. Phys. Anthropol. 53: 55, 1980.
Bleichrodt N., Garcia I., Rubio C., Morreale De Escobar G., Escobar Del Rey F. Developmental disorders associated with severe iodine deficiency. In: Hetzel B.S., Dunn J.T., Stanbury J.B. (Eds.), The prevention and control of iodine deficiency disorders. Elsevier, Amsterdam, 1987, p. 65.
DeLong R. Neurological involvement in iodine deficiency disorders. In: Hetzel B.S., Dunn J.T., Stanbury J.B. (Eds.), The prevention and control of iodine deficiency disorders. Elsevier, Amsterdam, 1987, p. 49.
Hetzel B.S., Chavadej J., Potter B.J. The brain and iodine deficiency. Neuropathol. Appl. Neurobiol. 14: 93, 1988.
Liu J.L., Tan J.B., Zhuang Z.J. et al. Influence of iodine deficiency on human fetal thyroid gland and brain. In: DeLong R., Robbins J. and Condliffe P.G. (Eds.), Iodine and the brain. Plenum Press, New York and London, 1989, p. 249.
Halpern J.P., Boyages S.C., Maberly G.F., Collins J.K., Eastman C.J., Morris J.G.L. The neurology of endemic cretinism. A study of two endemias. Brain. 114: 825, 1991.
Boyages S.C. Iodine deficiency disorders. J. Clin. Endocrinol. Metab. 77: 587, 1993.
Hetzel B.S., Potter B.J. Iodine deficiency and the role of thyroid hormones in brain development. In: Dresoti I.E. and Smith R.M. (Eds.), Neurobiology of the trace elements. Humana Press, New Jersey, 1983, p. 83.
Stanbury J.B. The consequences of iodine deficiency. The Endocrinologist. 219, 1993.
Gaitan E., Dunn J.T. Epidemiology of iodine deficiency. TEM. 3: 170, 1992.
Hetzel B. Iodine deficiency disorders (IDD) and their eradication. Lancet 2: 1126, 1983.
Delange F., Bastani F., Benmiloud M. et al. Definition of endemic goiter and cretinism, classification of goiter size and severity of endemias and survey techniques. In: Dunn J.T., Pretell E., Daza C., Viteri F.E. (Eds.), Toward the eradication of endemic goiter, cretinism, and iodine deficiency. PHAO Sci. Publ., Washington, 1986, vol. 502, p. 373.
Potter B.J., Mano M.T., Belling G.B. et al. Retarded fetal brain development resulting from severe dietary iodine deficiency in sheep. Neurophat. Appl. Neurobiol. 5: 103, 1982.
Stanbury J.B. The pathogenesis of endemic cretininism. J. Endocrinol. Invest. 7: 409, 1984.
Escobar Del Rey F., Mallol J., Morreale De Escobar G. Effects of maternal iodine deficiency on thyroid hormone economy of lactating dams and pups: Maintenance of normal cerebral 3,5,3′-triiodo-L-thyronine concentrations in pumps during major phases of brain development. Endocrinology. 121: 803, 1987.
Mano M.T., Potter B.J., Belling G.B., Chavadej J., Hetzel B.S. Fetal brain development in response to iodine deficiency in a primate model (callithrix jacchus jacchus). J. Neurol. Sci. 79: 287, 1987.
Hetzel B.S., Mano M.T. A review of experimental studies of iodine deficiency during fetal development. J. Nutr. 119: 145, 1989.
Morreale De Escobar G., Ruiz De Ona C., Obregon M.J., Morreale De Escobar F. Models of fetal iodine deficiency. In: DeLong R., Robbins J. and Condliffe P.G. (Eds.), Iodine and the brain. Plenum Press, New York and London, 1989, p. 249.
Pharoah P.O.D., Connolly K. A controlled trial of iodinated oil for the prevention of endemic cretinism: a long-term follow up. Int. J. Epid. 16: 68, 1987.
Muzzo S., Leiva L., Carrasco D. Possible etiological factors and consequences of a moderate iodine deficiency on intellectual coefficient of school age children. In: Medeiros-Neto G., Maciel R.M.B., Halpern A. (Eds.), Iodine deficiency disorders and congenital hypothyroidism. Ache. Sao Saulo, 1986, p. 1001.
Donati L., Venturi S., Andreani M. An iodine deficient area with endemic cretinism in the central Appennines: studies of neuropsychological development in schoolchildren. IDD Newsletter. 4: 11, 1988.
Bleichrodt N., Escobar del Rey F., Morreale de Escobar G., Garcia I., Rubio C. Iodine deficiency: implications for mental and psychomotor development in children. In: DeLong G., Robbins J., Ciondliffe P.G. (Eds.), Iodine and the brain. Plenum Press, New York, 1989, p. 269.
Boyages S.C., Collins J., Maberly G.F., Jupp J., Morris J., Eastman C.J. Iodine deficiency impairs intellectual and neuromotor development in apparently normal people: a study of rural inhabitans from North Central China. Med. J. Aust. 150: 676, 1989.
Fenzi G.F., Giusti L.F., Aghini-Lombardi F. Neuropsychological assessment in schoolchildren from an area of moderate iodine deficiency. J. Endocrinoi. Invest. 13: 427, 1990.
Vermiglio F., Sidoti M., Finocchiaro M.D. Defective neuromotor and cognitiveity in iodine-deficient schoolchildren of an endemic goiter region in Sicily. J. Clin. Endocrinol. Metab. 70: 379, 1990.
Wechsler D. Manual for the Wechsler Intelligence Scale of Children Revised. The Psychological Co., New York, 1974.
Posner M.I. Orienting of attention. Quarterly Journal of Experimental Psychology, 32: 3, 1980.
Aghini-Lombardi F., Pinchera A., Antonangeli L. Iodized salt prophylaxis of endemic goiter: an experience in Toscana (Italy). Acta Endocrinol. (Copenhn.) 129: 497, 1993.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lombardi, F.A., Pinchera, A., Antonangeli, L. et al. Mild iodine deficiency during fetal/neonatal life and neuropsychological impairment in Tuscany. J Endocrinol Invest 18, 57–62 (1995). https://doi.org/10.1007/BF03349700
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF03349700