Morphological Effect of Repeated Low 

 Dosage and Single High Dosage Application 

 of X-lrradiation to the Central Nervous 



System * 



WiLLIBALD SCHOLZ. WoLFGANG ScHLOTE. AND WOLFGANG HiRSCHBERGER 



Deutsche Forschungsanstalt fur Psychiatrie 

 Max-Planck-Institut, Munich, Germany 



This preliminary presentation deals with the effects of x-rays on the tissue 

 of the central ner\oiis system and the ensuinij pathogenesis. Although we 

 shall refer repeatedly to x-ray dosage, its relation to the time of manifestation 

 of tissue changes, and the se\erity of these changes, it is not our intention 

 to determine an exact time-dose relationship as this has been done by Berg 

 and Lindgren (1958). We ha\e tried to find a connection between the 

 delayed x-ray lesions seen after moderate single or fractionated doses and 

 the acute tissue necroses occurring within hours after a single application of 

 massi\e doses of hiyh intensity up to 80.000 r. It is now almost universally 

 accepted that the delayed lesions originate from changes ot the vessels. A 

 breakdown of the hematoencephalic barrier has been considered significant 

 since Mogilnitzky and Podljaschuk ( 1930) described the passage of trypan 

 blue into repeatedly irradiated central nervous tissue. When we made our 

 first investigations and experiments with dogs in 1932-1935 (Lyman et al., 

 1933; Scholz. 1935), the histologic picture was dominated to such a degree 

 by plasmatic transudations with and without erythrodiapedesis into the 

 central nervous tissue, it was difficult to admit any direct influence of the 

 x-rays on ner\ous tissue constituents. While it was true that the x-ray doses 

 applied through different portals to the skull ranged from 4,400 r to about 

 8.000 r, the intensity of irradiation was so low that to apply 12 skin erythema 

 doses corresponding to about 6.600 r. a radiation time of 6 hours was 

 required. Since that time, x-ray technicjue and the accurate measurement of 

 dosage has improved so considerably that it seemed worthwhile to re-examine 

 oiu" former results with new experimental material and methods. 



* This project was supported by the School of .\\iation Medicine of the .^ir Re- 

 search and Development Command. U.S. An Force, through its European Office. 



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