Evaluation of pathophysiology of early brain injury after aneurysmal subarachnoid hemorrhage and assessment of protective effect of brain hypothermia on early brain injury

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K09508
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56010:Neurosurgery-related
• Research Institution: Okayama University
• Principal Investigator: Hishikawa Tomohito 岡山大学, 医歯薬学域, 講師 (60509610)
• Co-Investigator(Kenkyū-buntansha): 平松 匡文 岡山大学, 大学病院, 助教 (50771953)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: くも膜下出血 / 早期脳損傷 / 脳低温療法

Outline of Final Research Achievements

Early brain injury after aneurysmal subarachnoid hemorrhage (SAH) worsens the neurological outcome. Dynamic changes in membrane potentials, intracranial pressure, cerebral perfusion pressure, cerebral blood flow, and extracellular glutamate levels were observed within 30 min after SAH. A prolonged duration of depolarization correlated with peak extracellular glutamate levels, and these two factors worsened the neuronal injury. Under brain hypothermia using pharyngeal cooling after SAH, cerebral perfusion pressure in the hypothermia group recovered earlier than that in the normothermia group. Extracellular glutamate levels in the hypothermia group were significantly lower than those in the normothermia group. The early induction of brain hypothermia could facilitate faster recovery of cerebral perfusion pressure, repolarization, and the inhibition of excessive glutamate release, which would prevent ultra-early brain injury following SAH.

Free Research Field

脳血管障害

Academic Significance and Societal Importance of the Research Achievements

脳動脈瘤破裂によるくも膜下出血は約半数が後遺症を残し、2割が死に至るいまだ予後不良な疾患である。発症72時間以内に生じる早期脳損傷が予後を悪化させる一因であり、早期脳損傷が起こるメカニズムは解明されつつあるが、これをターゲットとした治療は確立されていない。我々は本研究で早期に脳低温療法を行うことでくも膜下出血後の早期脳損傷を予防し得ることを示し、くも膜下出血患者の予後を改善させる上で意義がある研究と考える。