Bennett M H, Albin M S, Bunegin L, Dujovny M, Hellstrom H, Jannetta P J
Stroke. 1977 Jul-Aug;8(4):487-92. doi: 10.1161/01.str.8.4.487.
Brain retraction and induced hypotension are surgical adjuncts capable of compromising cerebral blood flow. To evaluate their effects upon brain function, cortical evoked potentials, neurological status and cortical histological changes were determined as a function of graded levels of brain retractor and systemic perfusion pressure in the dog. Somatosensory evoked potentials recorded from the site of application of brain retraction showed a decrement as a function of both the amount of retraction pressure and the systemic perfusion pressure. An electrode distant from the retractor site showed similar, though reduced and more variable changes in amplitude. For higher levels of brain retractor pressure, induced hypotension to 50 mm Hg systemic perfusion pressure produced greater reductions in evoked potentials than in normotensive subjects. It was demonstrated that a reduction of 50% of the evoked potential amplitude after sixty minutes brain retraction signaled, with high probability, the occurrence of postoperative sensory and/or motor deficits and cortical histopathology. It was concluded that cortical evoked potentials represent a reliable indicator of the functional effects produced by applied cortical retraction pressure at several levels of systemic perfusion pressure. It was suggested that the recording of evoked potentials would prove most useful during neurosurgical procedures employing induced hypotension and brain retraction.
脑回缩和诱导性低血压是可能会影响脑血流量的手术辅助手段。为评估它们对脑功能的影响，在犬身上测定了皮质诱发电位、神经状态和皮质组织学变化，这些指标是脑牵开器分级水平和全身灌注压的函数。从脑回缩应用部位记录的体感诱发电位显示，其随着回缩压力量和全身灌注压的变化而降低。远离牵开器部位的电极显示出类似的变化，不过幅度减小且变化更大。对于较高水平的脑牵开器压力，将全身灌注压诱导至50 mmHg时，诱发电位的降低幅度比正常血压受试者更大。结果表明，脑回缩60分钟后诱发电位幅度降低50%很可能预示着术后感觉和/或运动功能缺损以及皮质组织病理学改变的发生。得出的结论是，皮质诱发电位是在几个全身灌注压水平下应用皮质回缩压力所产生功能效应的可靠指标。有人提出，在采用诱导性低血压和脑回缩的神经外科手术过程中，诱发电位记录将证明是最有用的。
