Psychophysiologic aftereffects of prenatal irradiation.
Prenatally irradiated children (n = 544), who were born between 26 April 1986 and 26 February 1987, in regions of the Ukraine which were radioactively contaminated as a result of the Chernobyl disaster, their mothers and teachers have been examined with psychometric tests. The control group of relevant children (n = 759), their mothers and teachers, were living at the radioecological 'clear' regions (Kharkov and Kharkov Region). Further, we randomly selected 50 prenatally irradiated children whose mothers were evacuated from the Chernobyl exclusion zone and 50 age-and-gender-matched non-exposed children. At this phase clinical examinations, psychometric tests, computerized EEG, thyroid function assessment and dosimetric reconstruction were used. We found a significant increase in mental retardation (IQ < 70) and of borderline and low range IQ, as well as emotional and behavioral disorders and a decrease in high IQ (IQ > 110) in children irradiated in utero as a result of the Chernobyl disaster, in comparison with the controls. One important biological mechanism in the genesis of mental disorders in prenatally irradiated children is the radiation-induced malfunction of the thyroid-pituitary system with the effect threshold of 0.30 Sv of thyroid exposure dose. We hypothesize that the cerebral basis of mental disorders in the prenatally irradiated children is the malfunction of the left hemisphere limbic-reticular structures, particularly in those exposed at the most critical period of cerebrogenesis (8-25 weeks of gestation). The data obtained reveal mental disorders in prenatally irradiated children and obviously reflect developmental abnormalities of brain structure and function as a result of the interaction of prenatal and post-natal factors where it is possible to assume radiation effects on the developing brain. A follow-up study of the children irradiated in utero, who may be at risk for schizophrenia, is proposed because of its particular importance to clinical medicine and neuroscience.
Nyagu
A I
AI
Neurology Department, Academy of Medical Sciences of the Ukraine, Kiev, Ukraine.
Loganovsky
K N
KN
Loganovskaja
T K
TK
D001921:Brain / Q000503:physiopathology / Q000528:radiation effects; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000503:physiopathology*; D001931:Brain Mapping; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis / Q000503:physiopathology; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000175:diagnosis / Q000503:physiopathology; D007360:Intelligence / Q000528:radiation effects; D008297:Male; D009483:Neuropsychological Tests; D009688:Nuclear Reactors; D011210:Power Plants; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011594:Psychometrics; D011603:Psychophysiology; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000175:diagnosis / Q000503:physiopathology*; D018788:Radioactive Hazard Release; D014455:Ukraine