並列タイトル等Experimental study on brain damage by extracerebral compression
一般注記報告番号(甲第3号)
(Abstract 1)The effects of long-standing brain compression were investigated in 26 adult cats. Brain compression was produced by inserting 12 steel balls (5mm in diameter, at 10 minute intervals) into extradural space through a small bur hole in the left temporal bone. The animals were divided into six groups according to the compression period (1 hr, 6 hrs, 2 days, 7 days, 1 month and 6 months). In 10 cats of the 1 hr and 6 hr group, mean arterial blood pressure and intracranial pressure (ICP) were monitored during brain compression. Maximum distanc of midline shift (MS) and hemispheric area ratio (HAR), an index of the volume of the compressed hemisphere, were calculated and histological evaluation was made in detail. ICP progressively increased up to 30mmHg during ball insertion, but it returned to normal level within 6 hours. HAR showed marked reduction in the 1 and 6 month groups. Histologically, chromatolysis, degenaration of neurons and infiltration of microglia were found in the compressed cortex in the 2 day to 6 month groups. Gliosis and destruction of cortical architecture were found in the 1 and 6 month groups. These data shovv that intracranial mass causes prograssive atrophy of the brain tissue. Chromatolysis seems to be a major findin in the brain sustaining long-standing compression and it followed by severe degenaration of neurons and destruction of cortical architecture. Brain atrophy become apparent within 1 month of compression. These findings suggest that brain compression by intracranial mass must be removed within 1 month in order to avoid further brain tissue damage.
(Abstract 2)Effects of extracerebral compression on cerebral circulation and microvascular architecture were investigated in 23 adult cats. Brain compression was produced by inserting 12 steel balls (5 mm in diameter, at 10 minute intervals) into the extradural space through a burr hole in the left temporal bone. Mean arterial blood pressure (MABP), intracranial pressure (ICP) and cerebral blood flow (CBF) were measured continuously. Cerebral perfusion pressure (CPP) and cerebrovascular resistance (CVR) were then calculated. Microvascular architecture of he brain was studied by scanning electron microscope (SEM) in the cerebrovascular casting methods. CBF decreased significantly on the compressed side though CPP remained unchanged untili the insertion of 5th ball. CVR increased correlatively to the number of balls on the compressed side while it remained unchanged on the contralateral side. In SEM study, flexion and interruption of capillaries and the crossing and pressing phenomenon of the pial vessels were most remarkable in the compressed side. The degree of alteration in the microvascular architectures corresponds to the structural shift of the brain. These data show that increase of CVR correlating to alteration of microvascular architectures plays an important role in decrease of CBF in a compressed brain. It is suggested that intracranial mass lesions causing structural shift of brain must be removed in order to avoid further brain tissue damage due to microvascular lesions.
学位論文
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）