Mental function following scalp irradiation during childhood

Author: E. Ron, B. Modan, S. Flora et al.

Reference: Am. J. Epidemiol. — 1982. — Vol. 116. — P. 149–160.

Keywords: tinea captis treatment, radiation therapy, neurological consequences

Abstract: Between 1950 and 1960 about 20,000 israeli children were treated for tinea capitis by x-ray therapy as part of a large public health campaign to eradicate the disease. Dosimetric studies determined that these children were subjected to a mean brain dose of 130 rads. Almost 20 years later, possible radiation effects on the central nervous system were evaluated by comparing several measures of mental and brain function in approximately 11,000 of the irradiated children and in two nonirradiated, tinea-free comparison groups: (a) ethnic, sex- and age-matched individuals from the general population, and (b) siblings. While not all comparisons were statistically significant, there was a consistent trend for the irradiated subjects to exhibit signs of central nervous system inpairment more often than either comparison group. The irradiated children had lower examination scores on scholastic aptitude, intelligence quotient (IQ) and psychologic tests, completed fewer school grades, and had an increased risk for mental hospital admissions for certain disease categories. A slightly higher frequency of mental retardation was also suggested. These-long-lasting scholastic and mental health effects lead the authors to conclude that radiation to the immature brain may cause damage to the central nervous system.

URL: http://www.ncbi.nlm.nih.gov/pubmed/7102650

Low doses of ionizing radiation and circulatory diseases: a systematic review of the published epidemiological evidence

Author: McGale P., Darby S.C.

Reference: Radiat. Res. — 2005. — Vol. 163, № 3. — P. 247–257.

Keywords: circulatory system, atomic bomb survivors

Abstract: Recent analyses of mortality among atomic bomb survivors have suggested a linear dose–response relationship between ionizing radiation and diseases of the circulatory system for exposures in the range 0–4 Sv. If confirmed, this has substantial implications. We have therefore reviewed the published literature to see if other epidemiological data support this finding. Other studies allowing a comparison of the rates of circulatory disease in individuals drawn from the same population but exposed to ionizing radiation at different levels within the range 0–5 Gy or 0–5 Sv were identified through systematic literature searches. Twenty-six studies were identified. In some, disease rates among those exposed at different levels may have differed for reasons unrelated to radiation exposure, while many had low power to detect effects of the relevant magnitude. Among the remainder, one study found appreciable evidence that exposure to low-dose radiation was associated with circulatory diseases, but five others, all with appreciable power, did not. We conclude that the other epidemiological data do not at present provide clear evidence of a risk of circulatory diseases at doses of ionizing radiation in the range 0–4 Sv, as suggested by the atomic bomb survivors. Further evidence is needed to characterize the possible risk.

URL: http://www.bioone.org/doi/abs/10.1667/RR3314

ROS effects on neurodegeneration in Alzheimer’s disease and related disorders: on environmental stresses of ionizing radiation

Author: Manton K.G., Volovik S., Kulminski A.

Reference: Curr Alzheimer Res. — 2004. — Vol. 1, № 4. — 277–293.

Keywords: Alzheimer’s disease, CNS, ROS, Hiroshima, Nagasaki, Chernobyl, Ionizing radiation, ambiphilic, mitochondria, radionuclides, neurons, astrocytes, microglia

Abstract: Neurodegenerative processes associated with Alzheimer’s disease are complex and involve many CNS tissue types, structures and biochemical processes. Factors believed involved in these processes are generation of Reactive Oxygen Species (ROS), associated inflammatory responses, and the bio-molecular and genetic damage they produce. Since oxidative processes are essential to energy production, and to other biological functions, such as cell signaling, the process is not one of risk exposure, as for cigarettes and cancer, but one where normal physiological processes operate out of normal ranges and without adequate control. Thus, it is necessary to study the ambiphilicity that allows the same molecule (e.g., beta amyloid) to behave in contradictory ways depending upon the physiological microenvironment. To determine ways to study this in human populations we review evidence on the effects of an exogenous generator of ROS, ionizing radiation, in major population events with radionuclides (e.g., Hiroshima and Nagasaki; Chernobyl Reactor accident; environmental contamination in Chelyabinsk (South Urals) where plutonium was produced, and in the nuclear weapons test area in Semipalatinsk, Kazakhstan). The age evolution, and traits, of neurodegenerative processes in human populations in these areas, may help us understand how IR affects the CNS. After reviewing human population evidence, we propose a model of neurodegeneration based upon the complexity of CNS functions.

URL: http://www.ncbi.nlm.nih.gov/pubmed/15975057

Early gene expression profile in mouse brain after exposure to ionizing radiation

Author: Mahmoud-Ahmed A.S., Atkinson S., Wong C.S.

Reference: Radiat Res. ― 2006. ― Vol. 165, № 2. ― P. 142–154.

Keywords: gene expression, RNA, mice

Abstract: Acute changes in the gene expression profile in mouse brain after exposure to ionizing radiation were studied using microarray analysis. RNA was isolated at 0.25, 1, 5 and 24 h after exposure to 20 Gy and at 5 h after exposure of the whole brain of adult mice to 2 or 10 Gy. RNA was hybridized onto 15K cDNA microarrays, and data were analyzed using GeneSpring and Significant Analysis of Microarray. Radiation modulated the expression of 128, 334, 325 and 155 genes and ESTs at 0.25, 1, 5 and 24 h after 20 Gy and 60 and 168 at 5 h after 2 and 10 Gy, respectively. The expression profiles showed dose- and time-dependent changes in both expression levels and numbers of differentially modulated genes and ESTs. Seventy-eight genes were modulated at two or more times. Differentially modulated genes were associated with 12 different classes of molecular function and 24 different biological pathways and showed time- and dose-dependent changes. The change in expression of four genes (Jak3, Dffb, Nsep1 and Terf1) after irradiation was validated using quantitative real-time PCR. Up-regulation of Jak3 was observed in another mouse strain. In mouse brain, there was an increase of Jak3 immunoreactivity after irradiation. In conclusion, changes in the gene profile in the brain after irradiation are complex and are dependent on time and dose, and genes with diverse functions and pathways are modulated.

URL: http://www.ncbi.nlm.nih.gov/pubmed/16435913

Lymphocyte apoptosis control and neurodegeneration at the late period after the acute radiation syndrome

Author: D. Bazyka, I. Ilyenko, K. Loganovsky et al.

Reference: Abstracts of 17^th ECDO Euroconference on apoptosis «Destruction, degradation and death cell death control in cancer and neurodegeneration», September 23–26, 2009, Institut Pasteur, Paris, France. — P. 63.

Long-term follow-up for brain tumor development after childhood exposure to ionizing radiation for tinea capitis

Author: S. Sadetzki, A. Chetrit, L. Freedman et al.

Reference: Radiat. Res. — 2005. — Vol. 163, № 4. — P. 424–432.

Keywords: tinea capitis treatment, aftermath

Abstract: Ionizing radiation is an established risk factor for brain tumors, yet quantitative information on the long-term risk of different types of brain tumors is sparse. Our aims were to assess the risk of radiation-induced malignant brain tumors and benign meningiomas after childhood exposure and to investigate the role of potential modifiers of that risk. The study population included 10,834 individuals who were treated for tinea capitis with X rays in the 1950s and two matched nonirradiated groups, comprising population and sibling comparison groups. The mean estimated radiation dose to the brain was 1.5 Gy. Survival analysis using Poisson regression was performed to estimate the excess relative and absolute risks (ERR, EAR) for brain tumors. After a median follow-up of 40 years, an ERR/Gy of 4.63 and 1.98 (95% CI = 2.43-9.12 and 0.73-4.69) and an EAR/Gy per 10(4) PY of 0.48 and 0.31 (95% CI = 0.28-0.73 and 0.12-0.53) were observed for benign meningiomas and malignant brain tumors, respectively. The risk of both types of tumors was positively associated with dose. The estimated ERR/Gy for malignant brain tumors decreased with increasing age at irradiation from 3.56 to 0.47 (P = 0.037), while no trend with age was seen for benign meningiomas. The ERR for both types of tumor remains elevated at 30-plus years after exposure.

URL: http://www.ncbi.nlm.nih.gov/pubmed/15799699

Long-lasting cerebral functional changes following moderate dose X-radiation treatment to the scalp in childhood: an electroencephalographic power spectral study

Author: I. Yaar, E. Ron, B. Modan et al.

Reference: J. Neurol. Neurosurg. Psychiatry. — 1982. — Vol. 45, № 2. — P. 166–169.

Keywords: EEG, visual analyses, tinea capitis treatment

Abstract: EEG tracings were compared in 44 young adults who received scalp x-radiation treatment for tinea capitis during childhood and 59 non-irradiated control subjects. The irradiated subjects were exposed, over 20 years previously, to a mean dose of 130 rads to the brain. Visual analysis of the EEG revealed an insignificant excess of abnormalities among the irradiated subjects compared to the controls. Power spectral density function analysis showed increased power values among the irradiated subjects, particularly in the beta wave frequencies. This finding provides further evidence for suspecting that x-irradiation during brain maturation may cause long-lasting damage to the brain tissue. (full text in English available on web)

URL: http://jnnp.bmj.com/content/45/2/166.long

Cerebral basis of posttraumatic stress disorder following the Chernobyl disaster.

Author: Loganovsky KN, Zdanevich NA.

Reference: CNS Spectr. 2013, 18 (2): 95–102.

Keywords: PTSD, cerebrovascular pathology, hippocampus, depression

Abstract: BACKGROUND: Whether posttraumatic stress disorder (PTSD) following radiation emergency has psychopathological, neurocognitive, and neurophysiological peculiarities is at issue.

OBJECTIVE: The goal was to explore the features and cerebral basis of “radiation” PTSD in the survivors of the Chernobyl accident. Subjects and Methods The cross-sectional study included 241 people, 219 of whom have been diagnosed with PTSD according to the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria, among them 115 clean-up workers of the Chernobyl accident (34 with acute radiation sickness), 76 evacuees from the Chernobyl exclusion zone, 28 veterans of the war in Afghanistan, and 22 healthy unexposed individuals. Psychometric examinations, neurocognitive assessments, computerized electroencephalography, and cerebral vascular Doppler were used.

RESULTS: “Radiation” PTSD includes “flashforward” phenomena and anticipating stress (projection of fear and danger to the future); somatoform disorders (depression, trait and state anxiety); and neurocognitive deficit (impaired memory and attention, auditory-verbal memory and learning, proactive and retroactive interference, cerebellar and stem symptoms, intellectual changes). The intima-media component, thickness of common carotid arteries, and common and left internal carotid arteries stenosis rates are increased in the liquidators. Changes of bioelectrical brain activity as a decrease of beta- and theta-power, together with an increase of alpha-power, were found in the Chernobyl accident survivors with PTSD.

CONCLUSIONS: PTSD following radiation emergency is characterized by comorbidity of psychopathology, neurocognitive deficit, and cerebrovascular pathology with increased risk of cerebral atherosclerosis and stroke. The cerebral basis of this PTSD is proposed to be an abnormal communication between the pyramidal cells of the neocortex and the hippocampus, and deep brain structures. It is recommended that a system of emergency and long-term psychological and psychiatric care be organized for the survivors in Fukushima Daichi, Japan.

URL: http://www.ncbi.nlm.nih.gov/pubmed/23445934

Disrupted development of the dominant hemisphere following prenatal irradiation.

Author: Loganovsky KN, Loganovskaja TK, Nechayev SY, Antipchuk YY, Bomko MA.

Reference: J. Neuropsychiatry Clin Neurosci. 2008, 20 (3): 274–291.

Keywords:EEG patterns, children, mothers, WISC

Abstract: One hundred children, exposed prenatally to radiation after the Chernobyl nuclear power plant accident, and 50 non-exposed classmates were examined between the ages of 11 and 13 years old using neuropsychiatric tests, WISC, EEG, and visual evoked potentials. Individual prenatal radiation doses were reconstructed for all examined children. The exposed children were found to have more neuropsychiatric disorders, left-brain neurological signs, lower full-scale and verbal IQ, IQ discrepancies with verbal decrement, disorganized EEG patterns, an excess of lateralized-to-left frontotemporal region delta and beta power with depression of theta and alpha power, and interhemispheric inversion visual information processing. Mothers’ mental health, stress, and prenatal irradiation contributed to these effects, along with several confounding factors. (full text in English available on web.)

URL: http://neuro.psychiatryonline.org/article.aspx?articleID=103418

Intelligence deterioration following acute radiation sickness.

Author: Loganovsky K.N., Zdorenko L.L.

Reference: Clinical Neuropsychiatry. — 2012. — Vol. 9, № 5. — P. 187-194

Keywords: IQ, cognitive impairment, ARS

Abstract: Full text in English available on web.

URL: http://www.clinicalneuropsychiatry.org/pdf/Loganovsky_sito.pdf