Loganovsky K M, Kuts K V
State Institution National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine, 53 Melnykova Street, Kyiv, 04050, Ukraine.
Probl Radiac Med Radiobiol. 2016 Dec;21:264-290.
The study was aimed at evaluating features of brain information processes and cognitive functioning in the remote period after irradiation due to the Chornobyl accident by using cognitive evoked potentials P300.
The study included 128 people, 112 male Chornobyl clean up workers in 1986-1987 with the records of radiation doses available in Clinical and Epidemiological Registry (CER) of State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine» (NRCRM) (study group) and 16 unexposed persons due to the Chornobyl disaster (control group). At the time of the survey the average age of clean up workers (M ± SD) was (57.3 ± 5.9) years, range 44-65 years, and of unex posed persons was (57.3 ± 6.5) years, range 44-65 years. Radiation doses were within the range 0.0002-1.23 Gy, with the arithmetic mean dose (M ± SD) of (0.2 ± 0.2) Gy and the geometric mean dose of 0.1 Gy.
The radiocerebral effect in the projection of the left posterior superior temporal gyrus (Wernicke's area) proportionally to the radiation dose with the possible threshold of 0.05 Gy of total irradiation was revealed, with increasing radiation dose cognitive component P300 amplitude reduces and its latency period (LP) increases, espe cially at doses > 0.3-0.5 Gy. At doses > 0.5 Gy the functional relationship with the radiation dose for LP P300 increase in the projection of Wernicke's area (r = 0.9; p = 0.027) has been found.
The neurophysiological features detected are fully consistent with hypotheses both on radiosensitiv ity of human central nervous system and accelerated aging of the brain under the influence of small doses of ioniz ing radiation, and have questioned the feasibility of long term manned space flights (including Mars) until the development of adequate radiation hygiene standardization for space crews and invention of means for radiation protection of space flights. Further dynamic clinical and neurophysiological monitoring of individuals exposed to ionizing radiation is necessary. To identify the neurophysiological biological markers of ionizing radiation further international researches with adequate dosimetry support are needed.
本研究旨在通过认知诱发电位P300评估切尔诺贝利事故辐射后远期的脑信息处理特征和认知功能。
本研究纳入128人，其中112名男性为1986 - 1987年参与切尔诺贝利清理工作的人员，其辐射剂量记录可在乌克兰国家医学科学院国家辐射医学研究中心（NRCRM）的临床与流行病学登记处（CER）获取（研究组），以及16名未受切尔诺贝利灾难影响的人员（对照组）。在调查时，清理工作人员的平均年龄（M ± SD）为（57.3 ± 5.9）岁，年龄范围44 - 65岁，未受影响人员的平均年龄为（57.3 ± 6.5）岁，年龄范围44 - 65岁。辐射剂量范围为0.0002 - 1.23 Gy，算术平均剂量（M ± SD）为（0.2 ± 0.2）Gy，几何平均剂量为0.1 Gy。
发现左侧颞上回后部（韦尼克区）投射区域的放射性脑效应与辐射剂量成比例，总照射可能阈值为0.05 Gy，随着辐射剂量增加，认知成分P300的波幅降低，潜伏期（LP）延长，尤其是在剂量> 0.3 - 0.5 Gy时。在剂量> 0.5 Gy时，发现韦尼克区投射区域中P300潜伏期与辐射剂量之间存在功能关系（r = 0.9；p = 0.027）。
检测到的神经生理特征完全符合关于人类中枢神经系统放射敏感性以及小剂量电离辐射影响下脑加速老化的假设，并对长期载人航天飞行（包括火星任务）的可行性提出了质疑，直到为航天乘员制定出适当的辐射卫生标准化措施以及发明航天飞行辐射防护手段。有必要对受电离辐射的个体进行进一步的动态临床和神经生理监测。为确定电离辐射的神经生理生物标志物，需要在充分剂量测定支持下开展进一步的国际研究。
