Alterations of Neuropsychological Function and Cerebral Glucose Metabolism After Cardiac Surgery Are Not Related Only to Intraoperative Microembolic Events

Abstract

Background and Purpose-High-intensity transient signals (HITS) during cardiac surgery are capable of causing encephalopathy and cognitive deficits. This study was undertaken to determine whether intraoperative HITS cause alterations of neuropsychological function (NPF) and/or cerebral glucose metabolism (CMRGlc), even in a low-risk patient group, and whether induced changes are interrelated. Methods-Eighteen patients without signs of cerebrovascular disease underwent elective coronary artery bypass grafting (CABG), and two of these additionally underwent valve replacement in normothermia. Intraoperatively, HITS were recorded by means of transcranial Doppler ultrasonography (TCD). Perioperatively, NPF and CMRGlc were assessed using a standardized complex test battery and positron emission tomography with 18 F-2-fluoro-2-deoxy-D-glucose (FDG-PET), respectively. Results-Intraoperatively, the number of HITS ranged from 90 to 1710 per patient and hemisphere, more on the right side than on the left (PϽ.05). HITS occurred primarily during cardiopulmonary bypass (71.3%) and, to a lesser extent, during aortic manipulation (22.2%). Changes in global and regional CMRGlc between first (one day preoperatively) and second (8 to 12 days postoperatively) FDG-PET scans were mild. No correlations were found between the number of HITS, age of patient, duration of cardiac ischemia or cardiopulmonary bypass and the changes in CMRGlc. In patients with recorded HITS and a postoperative decrease of regional CMRGlc (nϭ11), the maximal decrease of rCMRGlc in each hemisphere below the individual global change of CMRGlc correlated with the number of HITS (rϭϪ0.46, PϽ.05). Limitations in NPF occurred 8 to 12 days postoperatively, resolved within 3 months, and were not found to be correlated to the absolute number of HITS or changes in CMRGlc. Conclusions-HITS during cardiac surgery can cause alterations of both NPF and CMRGlc, even in a low-risk patient group.However, the number of HITS and changes in NPF and CMRGlc are not necessarily interrelated, which indicates that (1) the location of brain damage related to HITS is more important for the development of NPF than is the absolute number of HITS, and (2) factors in addition to HITS might contribute to surgery-related brain damage. (Stroke. 1998;29:660-667.)

Assessing postoperative cognitive change after cardiopulmonary bypass surgery.

“…Visual-spatial attention also involves regions of parietal cortex (Posner, Cohen, & Rafal, 1982;Posner, Walker, Friedrich, & Rafal, 1987). In this regard, it is interesting that postoperative declines in glucose metabolism have been noted in the frontal and parietal (as well as inferior temporal and occipital) regions of the cerebral cortex 8 to 12 days after CPB (Jacobs et al, 1998). Because attention itself can be decomposed into several specialized subcomponents (Parasuraman, 1984;Posner & Cohen, 1984;Treisman & Gelade, 1980), the results of the present study suggest that a detailed analysis of the particular aspects of attention that are affected by CPB would be valuable.…”

Pharmacology and Biological Efficacy of a Recombinant, Humanized, Single-Chain Antibody C5 Complement Inhibitor in Patients Undergoing Coronary Artery Bypass Graft Surgery With Cardiopulmonary Bypass

“…[43][44][45][46] The cause of the cognitive decline is believed to be related to multifocal ischemic and/or hypoxic insults to the brain, leading to neuronal loss. [47][48][49][50][51] In the present investigation, the cognitive measure used was the MMSE, which assesses global cognitive function. However, despite the constraints of a small sample size and the sensitivity/specificity of the MMSE, the observation that significantly fewer patients treated with the 2 mg/kg dose of h5G1.1-scFv exhibited visuospatial deficits and language deficits on postoperative days 5 to 7 than the placebo group suggests that h5G1.1-scFv may have the potential to ameliorate post-CPB cognitive decline and warrants further investigation.…”

Neurological Complications in Aortic Valve Surgery and Rehabilitation Treatment Used

“…Strokes cause major disability and high rehabilitation costs because these patients most often require the use of different technical aids or orthotics for walking, wheelchairs, adaptation of their home due to architectural barriers, help from third parties and in some cases the everyday need for health care staff, requiring admission to specialised homes. Martin C et al, 2007) Encephalopathy is usually secondary to a diffuse cerebral injury, and is believed to originate from multiple microembolic events or hypoperfusion (Jacobs et al, 1998). This clinical situation manifests itself in various ways, but it is diagnosed as a state of global impairment of cognitive functions, a reduced level of consciousness that is sometimes prolonged, hallucinations, and increased or decreased psychomotor activity.…”