Whether low doses of ionizing radiation affect the human brain?
Author: K.N. Loganovsky
Reference: Український медичний часопис (Ukrainian Medical Magazine), 2009
Keywords: ionizing radiation, low doses, Chernobyl accident, brain, radiosensitivity, radiocerebral effects, exposure in utero.
Abstract: The aim is to analyze the current evidences on radiocerebral effects following exposure to 20 mSv on fetus and >300 mSv on thyroid in utero; 16–25 weeks — >10 mSv and >200 mSv, respectively. A life span study should be done for the cohort of prenatally irradiated persons as a result of the Chernobyl accident,as well as those exposed at the age of 0–1 years. These survivors are under increased risk of different neuropsychiatric disorders, including schizophrenia. Radiation exposure in childhood is obviously associated with dose-related cognitive decline in adulthood and neuropsychiatric disorders, including schizophrenia, later in life. The possible dose thresholds of delayed radiation brain damage are the doses as low as 0.1–1.3 Gy on the brain in childhood. In adults, the radiation-associated cerebrovascular effects were obtained at >0.15–0.25 Sv. Dose-related neuropsychiatric, neurophysiological, neuropsychological, and neuroimaging abnormalities following exposure to >0.3 Sv, neurophysiological and neuroimaging radiation markers at doses >1 Sv were revealed. Postradiation brain damage is predominantly localized in the frontal-temporal areas of the left hemisphere and involves both white and gray matter of the brain. The cerebral structural and functional abnormalities after irradiation are characteristic as frontal and temporal cortex atrophy, changes of subcortical structures and neuronal pathways, mainly in the dominant hemisphere. Adulthood radiation exposure is the risk factor for the Chronic Fatigue Syndrome as the predisposition for neurodegeneration, cognitive deficit and other neuropsychiatric disorders development, accelerating CNS ageing, as well as the new model of schizophrenia. Studies on radiation neuropsychiatric effects should be realized.
URL: http://www.umj.com.ua/wp-content/uploads/archive/71/pdf/1440_rus.pdf?upload
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