ARTERIAL HYPERTENSION AND IRRADIATION DAMAGE TO THE NERVOUS SYSTEM

Journal Article · Sat Dec 29 04:00:00 EST 1962 · Lancet (England)

DOI:https://doi.org/10.1016/S0140-6736(62)91020-6· OSTI ID:4645454

Asscher, A W; Anson, S G

On the basis of previous studies it appeared that irradiation damage to the nervous system might be more severe and more easily produced in hypertensive than in normotensive subjects. This hypothesis was investigated by studying the frequency of neurological complications and vascular lesions in the spinal cord after x irradiation of the cord in hypertensive and normotensive rats. Two weeks before irradiation of the spinal cord, a clip was applied to the right renal artery of the animals to produce hypertension. Single doses of 1500, 2000, or 3000 r were administered to the spinal cord in the cervical and upper thoracic region of hypertensive rats (systolic blood pressure higher than 145 mm Hg) and normotensive rats. After 1500 r to spinal cord, no abnormalities were noted in the normotensive controls during the period of observation. Some hypertensive animaIs showed transient abnormalities of gait, and during the following week died suddenly. Those remaining died unexpectedly 35-259 days after irradiation without apparent preceding neurological manifestations, although acute vascular lesions were found in the irradiated regions of the spinal cord. The normotensive controls of the 2000-r group showed no abnormalities of gait or of tail sensation, but the hypertensive rats died 67-243 days after irradiation, and ntaxic episodes preceding these unexpected deaths in one animal. Ristologically, the irradiated segments of the cords showed multiple focal acute vascular necrosis. The smaller arteries in irradiated segments of the cords showed hyaline thickening; some of the smaller vessels were widely dilated and filled with blood, and their walls were necrotic. The white matter of the irradiated parts of these cords showed numerous holes (status spongiosus) in the lateral and dorsal columns. The anterior-horn cells in the irradiated zones were swollen, their nuclei pyknotic and cytoplasm devoid of Nissl granules. No abnormalities, besides thickening of the meninges in the irradiated areas, were found in the cords of the normotensive controls. After 3000 r the normotensive animals of this group showed no abnormalities of gait and Survived normally; no vascular lesions were found in their spinal cords. The hypentensive animals died suddenly 43-70 days after irradiation of the cord, and in all, death was preceded by ataxic episodes. Postmortem, numerous foci of acute vascular necrosis were found in the irradiated cord. These experiments suggest that moderate arterial hypertension seriously modifies the effect of x irradiation of the spinal cord. The transience of the ataxia in irradiated hypertensive rats suggests a possible origin in reversible vasoconstriction. When such episodes were followed by sudden death, arterial necrosis was invariably present in the irradiated region of the cord. Moreover, in hypertensive animals in which paraplegia developed, there was widespread necrosis of nerve tissue as well as organized vascular necrosis. A search of hospital records revealed three cases in which high blood pressure was recorded along with necrosis of the brain or spinal cord following therapeutic irradiation. In two of these, large doses of irradiation had been administered, and the necrosis might have been due to irradiation alone. In the third case, however, necrosis of the spinal cord occurred artd one factor which may have determined this individual sensitivity was high blood pressure. (BBB)

• Research Organization: London Hospital
• NSA Number: NSA-17-038811
• OSTI ID: 4645454
• Journal Information: Lancet (England), Journal Name: Lancet (England) Vol. Vol: 2; ISSN LANCA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BEHAVIOR
BIOLOGY AND MEDICINE
BLOOD CIRCULATION
BLOOD VESSELS
BRAIN
CYTOLOGY
DISEASES
MAN
NERVOUS SYSTEM
PRESSURE
RADIATION DOSES
RADIATION EFFECTS
RADIATION INJURIES
RADIOTHERAPY
RATS
TISSUES
X RADIATION