Coronary artery bypass grafting with single cross-clamp results in fewer persistent neuropsychological deficits than multiple clamp or off-pump coronary artery bypass grafting.

BACKGROUND: In coronary artery bypass grafting (CABG) patients, neuropsychological deficits that are present from the time of the operation through 6 months postoperatively are considered permanent and represent organic brain damage related to the operation. We hypothesized that changes in our surgical method would reduce persistent deficits. METHODS: From 1999 to 2004, consenting CABG patients were randomly assigned to multiple aortic cross-clamp or single aortic cross-clamp technique. An additional contemporary group of patients treated with off-pump CABG was studied. All patients underwent an 11-part neuropsychologic examination preoperatively, and at 1 week, 6 weeks, and 6 months postoperatively. One hundred seven patients with no postoperative neurologic deficits had neuropsychologic examinations at all four testing periods. RESULTS: Off-pump CABG patients were significantly younger (60 +/- 11 years) than multiple aortic cross-clamp (66 +/- 8 years) and single aortic cross-clamp (64 +/- 9 years; p < 0.05) patients. At 6 months, 26% of 27 multiple aortic cross-clamp patients had neuropsychological deficits, 27% of 26 off-pump CABG patients had neuropsychological deficits, and only 9% of 54 single aortic cross-clamp patients had neuropsychological deficits (p = 0.067 versus multiple aortic cross-clamp and off-pump CABG). CONCLUSIONS: These results suggest that surgical technique is very important in determining cognitive outcome after CABG. Cardiopulmonary bypass is not the most important factor in determining outcome and when carefully performed with single cross-clamp and minimal aortic manipulation is equal or may be superior to off-pump operation. We suspect that mild hypothermia in on-pump surgery is additionally neuroprotective, a factor that should be taken into account when planning an operation.

Preliminary report: functional MRI of the brain may be the ideal tool for evaluating neuropsychologic and sleep complaints of patients with primary hyperparathyroidism.

BACKGROUND: The incidence, pattern, and severity of sleep disturbance and cognitive dysfunction has not been well characterized for patients with primary hyperparathyroidism (PHPT). There is no agreement on the mechanism of the development or resolution of such symptoms, and in no previous study has cerebral activity been functionally assessed and change documented following surgical cure of patients with PHPT. METHODS: We undertook a prospective analysis to obtain pilot data on 6 patients with PHPT. Functional magnetic resonance imaging (fMRI), formal neuropsychologic (NP) tests, and health-related quality of life (HRQL) measures that included sleep assessments were performed on patients before and after parathyroidectomy. Changes in cortical activation under both conflict and neutral conditions (distracting tasks) were recorded. RESULTS: Functional MRI demonstrated postoperative changes in medial prefrontal cortex activity during cognitive processing of conflict and nonconflict tasks. Further postoperative changes were noted in the dorsolateral prefrontal cortex and parietal cortex with shifts in activations. In addition to the fMRI findings, the patients demonstrated improvements in sleep and social behavior. They tended to experience less fatigue and their processing speed on cognitive tests improved. CONCLUSIONS: These data support the feasibility and willingness of patients with PHPT to undergo fMRI assessment. Preliminary findings reflected a generalized improvement in processing efficiency postoperatively compared with a patient's preoperative state, and the HRQL measures showed improved sleep. These findings mirror those expected with sleep dysfunction. Longitudinal assessment with advanced brain imaging technology, neuropsychological (NP), and sleep evaluations is warranted to further explore cognitive, sleep, and HRQL improvement after parathyroidectomy.

Single crossclamp improves 6-month cognitive outcome in high-risk coronary bypass patients: the effect of reduced aortic manipulation.

OBJECTIVE: We hypothesized that a strategy that reduced aortic manipulation would reduce the incidence of cognitive deficits in patients undergoing coronary artery bypass grafting compared with the "traditional" approach and that neurobehavioral outcomes with the reduced aortic manipulation strategy would approach those obtained with off-pump coronary artery bypass surgery. METHODS: Consenting high-risk patients (those with older age, diabetes, or hypertension) scheduled for coronary artery bypass grafting and cardiopulmonary bypass were randomly assigned to 1 of 2 aortic management protocols: (1) a traditional approach in which distal anastomoses were accomplished while the aorta was crossclamped but in which proximal anastomoses were sewn while a partial occlusion clamp was applied to the aorta (multiple aortic clamping group) or (2) a reduced aortic manipulation approach in which the aorta was clamped a single time with a reduced-pressure clamp (single aortic clamping group) and the partial occlusion clamp was not used. A contemporaneous group of patients undergoing off-pump coronary artery bypass surgery without cardiopulmonary bypass was also enrolled. Subjects in all 3 groups underwent neurologic and neuropsychological testing before and after surgery. After randomization, patients assigned to either approach could be changed to another strategy if the attending surgeon determined that patient safety demanded this change. The study design anticipated that surgical techniques would evolve over the course of patient enrollment and anticipated that some patients would have intraoperative echocardiographic findings that would demand that the traditional approach (eg, severe aortic atherosclerosis) or the reduced manipulation protocol (eg, severe ischemia or poor left ventricular function) be abandoned. Thus, an unequal distribution of patients was expected. By surgeon decision, 20 of 84 multiple aortic clamping patients crossed over to single aortic clamping, and 3 of 85 single aortic clamping patients switched to multiple aortic clamping. Eligible patients had a battery of neuropsychological tests before surgery and at 6 months after surgery. A 20% decrement in 2 or more tests was defined as a neuropsychological deficit. RESULTS: [table: see text]. CONCLUSIONS: A surgical strategy designed to minimize aortic manipulation can significantly reduce the incidence of cognitive deficits in coronary artery bypass grafting patients compared with traditional techniques. In this series, the results of the reduced aortic manipulation strategy were not significantly different from those in patients having off-pump coronary artery bypass surgery, thus emphasizing surgical technique as the primary cause of brain damage in coronary artery bypass grafting patients.

Primary hyperparathyroidism, cognition, and health-related quality of life.

OBJECTIVE: To provide a rigorous and critical review of studies in which formal neuropsychological (NP) testing and measurement of health-related quality of life (HRQL) were conducted pre- and post-parathyroidectomy for primary hyperparathyroidism (PHPT). These data contribute to the discussion on the utility of surgical intervention for nonclassic PHPT. SUMMARY BACKGROUND DATA: PHPT is a complex endocrinopathy involving calcium metabolism and a potent hormone made by the parathyroid glands. Approximately 1.5% of Americans age 65 years and older, representing more than 3.9 million people, have PHPT, and the prevalence in postmenopausal women is estimated at 3.4%. Current National Institutes of Health guidelines for curative, surgical intervention of PHPT exclude 80% of patients with hyperparathyroid disease who have subjective neurobehavioral and physical symptoms that affect the quality of their lives. METHODS: An electronic search was conducted of prospective studies in which cognitive functioning was measured with formal NP tests and HRQL was measured with valid and reliable instruments before and following parathyroidectomy for PHPT. RESULTS: : In studies conducted pre- and post-parathyroidectomy for PHPT, 6 small studies of cognitive functioning report inconsistent findings; however, 7 well-designed studies of HRQL report improvement across multiple domains following surgery. CONCLUSIONS: Surgical treatment of PHPT is a viable option for patients with laboratory diagnosed, "nonclassic" PHPT. Formal NP testing and evaluation of HRQL are useful tools that may assist physicians in choosing whom to refer for parathyroidectomy. Further longitudinal study of NP functioning and HRQL in patients with laboratory diagnosed PHPT is warranted.

Clinical trial of the neuroprotectant clomethiazole in coronary artery bypass graft surgery: a randomized controlled trial.

BACKGROUND: The neuroprotective property of clomethiazole has been demonstrated in several animal models of global and focal brain ischemia. In this study the authors investigated the effect of clomethiazole on cerebral outcome in patients undergoing coronary artery bypass surgery. METHODS: Two hundred forty-five patients scheduled for coronary artery bypass surgery were recruited at two centers and prospectively randomized to clomethiazole edisilate (0.8%), 225 ml (1.8 mg) loading dose followed by a maintenance dose of 100 ml/h (0.8 mg/h) during surgery, or 0.9% NaCl (placebo) in a double-blind trial. Coronary artery grafting was completed during moderate hypothermic (28-32 degrees C) cardiopulmonary bypass. Plasma clomethiazole was measured at several intervals during and up to 24 h after the end of infusion. A battery of eight neuropsychological tests was administered preoperatively and repeated 4-7 weeks after surgery. Analysis of the change in neuropsychological test scores from baseline was used to determine the effect of treatment. RESULTS: Neuropsychological assessments were completed in 219 patients (110 clomethiazole; 109 placebo). The mean plasma concentration of clomethiazole during surgery was 66.2 microm. There was no difference between the clomethiazole and placebo group in the postoperative change in neuropsychological test scores. CONCLUSION: Clomethiazole did not improve cerebral outcome following coronary artery bypass surgery.

Caveats in the neuropsychological assessment of African Americans.

This preliminary investigation examined the predictive accuracy of six neuropsychological tests in a population of non-brain-injured African Americans. False positives were unacceptably high on five of the neuropsychological tests administered. These pilot data raise important questions about the utility of neuropsychological test norms with groups dissimilar in sociocultural background to the normative population. These findings are examined in terms of the relative merits of the race-homogenous and race-comparative paradigms and underscore the importance of conducting normative studies that involve ethnic minority populations.