Statins reduce neurologic injury in asymptomatic carotid endarterectomy patients.

BACKGROUND AND PURPOSE: Statins are neuroprotective in a variety of experimental models of cerebral injury. We sought to determine whether patients taking statins before asymptomatic carotid endarterectomy exhibit a lower incidence of neurological injury (clinical stroke and cognitive dysfunction). METHODS: A total of 328 patients with asymptomatic carotid stenosis scheduled for elective carotid endarterectomy consented to participate in this observational study of perioperative neurological injury. RESULTS: Patients taking statins had a lower incidence of clinical stroke (0.0% vs 3.1%; P=0.02) and cognitive dysfunction (11.0% vs 20.2%; P=0.03). In a multivariate regression model, statin use was significantly associated with decreased odds of cognitive dysfunction (odds ratio, 0.51 [95% CI, 0.27-0.96]; P=0.04). CONCLUSIONS: Preoperative statin use was associated with less neurological injury after asymptomatic carotid endarterectomy. These observations suggest that it may be possible to further reduce the perioperative morbidity of carotid endarterectomy. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00597883.

The Original Cushing Society: A Historical Review of the Senior Society's First 6 Meetings.

The Society of Neurological Surgeons (SNS), founded in 1920, is one of the oldest neurosurgical society in the world. The founding members were prominent surgeons that met with the idea of furthering the field of neurosurgery. Initial meetings were forums to observe and discuss new surgeries. During the first 6 meetings of the SNS, surgical cases from the areas of cranial trauma, epilepsy, spinal cord tumors, brain tumors, pituitary tumor, trigeminal neuralgia, and cerebellar tumors were discussed. Publications from the members during that time included articles on the use of intracranial hypertonic saline, trigeminal neuralgia, brachial plexus injuries, management of head injury, spinal cord tumors, cervical spine trauma, and intracranial hemorrhage in the newborn. The members also invited lecturers from other specialties, such as neurology, ophthalmology, radiology, and pathology, typifying the interdisciplinary nature of neurosurgical practice. The meetings served as a forum to build consensus on neurosurgical treatment methods. Cases that ultimately changed the practice of neurosurgery at that time will be profiled. The SNS began as a traveling club of neurosurgical leaders who learned from each other's clinical experience to mold this burgeoning new field. However, the members made an impact on how neurosurgery was practiced nationally.

Inducible nitric oxide synthase promoter polymorphism affords protection against cognitive dysfunction after carotid endarterectomy.

BACKGROUND AND PURPOSE: Cognitive dysfunction occurs in 9% to 23% of patients during the first month after carotid endarterectomy (CEA). A 4-basepair (AAAT) tandem repeat polymorphism (either 3 or 4 repeats) has been described in the promoter region of inducible nitric oxide synthase (iNOS), a gene with complex roles in ischemic injury and preconditioning against ischemic injury. We investigated whether the 4-repeat variant (iNOS(+)) affects the incidence of cognitive dysfunction after CEA. METHODS: One-hundred eighty-five CEA and 60 spine surgery (control) subjects were included in this nested cohort analysis. Subjects underwent a battery of 7 neuropsychometric tests before and 1 day and 1 month after surgery. Multivariate logistic regression analyses were performed to determine if the iNOS promoter variant was independently associated with the incidence of cognitive dysfunction at 1 day and 1 month. Further, all right-hand-dominant CEA subjects were grouped by operative side and performance on each test was compared between iNOS(+) and iNOS(-) groups. RESULTS: Forty-four of 185 CEA subjects had at least 1 iNOS promoter allele containing 4 copies of the tandem repeat (iNOS(+)). iNOS(+) status was significantly protective against moderate/severe cognitive dysfunction 1 month after CEA. Right-hand-dominant iNOS(+) CEA subjects undergoing left-side CEA performed significantly better than iNOS(-) subjects on a verbal learning test and those undergoing right-side CEA performed significantly better on a test of visuospatial function. CONCLUSIONS: We demonstrate an iNOS promoter polymorphism variant provides protection against moderate/severe cognitive dysfunction 1 month after CEA. Further, this protection appears to involve cognitive domains localized ipsilateral to the operative carotid artery.

Neurocognitive performance in hypertensive patients after spine surgery.

BACKGROUND: Cognitive dysfunction is fairly common after noncardiac surgery and may be related to intraoperative blood pressure management. The authors present an analysis of risk factors for cognitive deterioration after spine surgery in older patients, with particular emphasis on intraoperative blood pressure in normotensive and hypertensive patients. METHODS: This is a post hoc cohort analysis of 45 patients enrolled before undergoing lumbar laminectomy or microdiscectomy. The patients underwent a battery of 5 neuropsychometric tests preoperatively, and 1 day and 1 month postoperatively. Computerized anesthesia records were used to obtain intraoperative mean arterial pressure (MAP) data. Simple linear regressions between intraoperative MAP and postoperative cognitive performance were performed, and multivariate linear regression models of postoperative cognitive performance were constructed to analyze potential risk factors for cognitive decline after surgery. RESULTS: Twenty-one normotensive patients (mean age, 62.4 yr) and 24 hypertensive patients (mean age, 67.9 yr) were included in this analysis. There was a significant positive relationship between minimum intraoperative MAP values and 1-day cognitive performance by simple linear regression in hypertensive (P = 0.003), but not normotensive, patients. In multivariate linear regression analysis of cognitive performance, there was a significant interaction between hypertension and minimum intraoperative MAP at 1 day and 1 month. CONCLUSIONS: In hypertensive patients, there was a significant relationship between minimum intraoperative MAP and decline in cognitive function 1 day and 1 month after surgery. A prospective controlled trial of intraoperative blood pressure control, especially during induction of anesthesia when MAP values typically drop, is needed to confirm these findings.

Intraoperative magnesium infusion during carotid endarterectomy: a double-blind placebo-controlled trial.

OBJECT: Recent data from both experimental and clinical studies have supported the use of intravenous magnesium as a potential therapy in the setting of cerebral ischemia. This study assessed whether intraoperative magnesium therapy improves neuropsychometric testing (NPT) following carotid endarterectomy (CEA). METHODS: One hundred eight patients undergoing CEA were randomly assigned to receive placebo infusion or 1 of 3 magnesium-dosing protocols. Neuropsychometric testing was performed 1 day after surgery and compared with baseline performance. Assessment was also performed on a set of 35 patients concurrently undergoing lumbar laminectomy to serve as a control group for NPT. A forward stepwise logistic regression analysis was performed to evaluate the impact of magnesium therapy on NPT. A subgroup analysis was then performed, analyzing the impact of each intraoperative dose on NPT. RESULTS: Patients treated with intravenous magnesium infusion demonstrated less postoperative neurocognitive impairment than those treated with placebo (OR 0.27, 95% CI 0.10-0.74, p = 0.01). When stratified according to dosing bolus and intraoperative magnesium level, those who were treated with low-dose magnesium had less cognitive decline than those treated with placebo (OR 0.09, 95% CI 0.02-0.50, p < 0.01). Those in the high-dose magnesium group demonstrated no difference from the placebo-treated group. CONCLUSIONS: Low-dose intraoperative magnesium therapy protects against neurocognitive decline following CEA.

A study of cognitive dysfunction in patients having carotid endarterectomy performed with regional anesthesia.

BACKGROUND: In previous studies, we found that approximately 25% of patients having carotid endarterectomy with general anesthesia (CEA general) develop cognitive dysfunction compared with a surgical control Group 1 day and 1 mo after surgery. In this study, we tested the hypothesis that patients having CEA with regional anesthesia (CEA regional) will develop significant cognitive dysfunction 1 day after surgery compared with a control group of patients receiving sedation 1 day after surgery. We did not study persistence of dysfunction. METHODS: To test this hypothesis, we enrolled 60 patients in a prospective study. CEA regional was performed with superficial and deep cervical plexus blocks in 41 patients. The control group consisted of 19 patients having coronary angiography or coronary artery stenting performed with sedation. A control group is necessary to account for the "practice effect" associated with repeated cognitive testing. The patients from the CEA regional group were enrolled at New York Medical Center and the control group at Columbia-Presbyterian Medical Center. The cognitive performance of all patients was evaluated using a previously validated battery of neuropsychometric tests. Differences in performance, 1 day after compared with before surgery, were evaluated by both event-rate and group-rate analyses. RESULTS: On postoperative day 1, 24.4% of patients undergoing CEA regional had significant cognitive dysfunction, where "significant" was defined as a total deficit score > or =2 SD worse than the mean performance in the control group. CONCLUSIONS: Patients undergoing CEA regional had an incidence of cognitive dysfunction which was not different than patients having CEA general as previously published and compared with a contemporaneously enrolled group.

The advisory dean program: a personalized approach to academic and career advising for medical students.

Advising and mentoring programs for medical students vary in their official names, scope, and structures. Catalyzed by negative student feedback regarding career advising and a perceived disconnection between faculty and students, in academic year 2003-2004, Columbia University College of Physicians and Surgeons implemented its formal Advisory Dean (AD) Program and disbanded its former advising system that used faculty volunteers. The AD Program has become a key element for enhancing the students' professional development throughout their student training, focusing on topics including, but not limited to, career counseling, professionalism, humanism, and wellness resources. Advisory deans and the dean for student affairs, familiar with resources for academic development, student support, and extracurricular activities, operate at the nexus of the program, providing personalized mentoring and advising for each student. Fully supported by administration and faculty, the program has shown early success according to student feedback. Early feedback from the Class of 2006, who had been involved in our AD Program for three years, has been encouraging. Out of 152 students, 104 (68%) provided feedback, with 93 (89%) of the respondents reporting the AD Program as a valuable initiative. Expecting to further improve on this early positive response, the AD Program will continue to foster an environment conducive to a seamless transition from student to physician.

Naval aviation and neurosurgery: traditions, commonalities, and lessons learned. The 2007 presidential address.

In his presidential address to the American Association of Neurological Surgeons, the author recounts lessons he learned while training to be a Naval Aviator and later a neurosurgeon. He describes his life as an aviator and neurosurgeon, compares naval aviation and neurosurgery, and points out lessons that neurosurgery can learn from naval aviation.

J. Lawrence Pool, M.D.: a pioneer in vascular neurosurgery.

The authors detail the life and career of Dr. J. Lawrence Pool, as well as his significant contributions to the field of cerebrovascular neurosurgery. The discipline of cerebrovascular neurosurgery is a young and dynamic field, which underwent rapid and substantial growth during the middle of the twentieth century. As the chairman of the Department of Neurological Surgery at the Neurological Institute of New York, Dr. J. Lawrence Pool was instrumental in the development of new techniques and devices that would ultimately result in decreased mortality rates and improved results from complex cerebrovascular procedures. Passion, ingenuity, and a pioneering spirit fueled Dr. Pool, whose introduction of the operating microscope and use of temporary clip occlusion during aneurysm repair revolutionized the field of cerebrovascular neurosurgery.

A controlled prospective study of neuropsychological dysfunction following carotid endarterectomy.

BACKGROUND: Although subtle cognitive injury as revealed by neuropsychological testing occurs in a substantial number of patients following carotid endarterectomy (CEA), there is controversy about whether this finding is a result of the surgery or the anesthesia. OBJECTIVES: To examine the changes in neuropsychological test performance in patients following CEA vs a control group of patients older than 60 years following spine surgery, so as to determine whether neuropsychological dysfunction after CEA is a result of surgery or anesthesia. METHODS: Patients undergoing CEA (n = 80) and lumbar spine surgery (n = 25) were assessed with a battery of neuropsychological tests preoperatively and on postoperative days 1 and 30. The neuropsychological performance of patients in the control group was used to normalize performance for patients in the CEA group, by calculating z scores using the mean and SD of the change scores in the control group. Significant cognitive dysfunction was defined as performance that exceeded 2 SDs above the mean performance of patients in the control group. RESULTS: Postoperative days 1 and 30 total deficit scores were significantly worse in the CEA group compared with the controls. When individual test results were examined, the CEA group performed significantly worse than the controls on the Rey Complex Figure test and Halstead-Reitan Trails B on day 1, and on the Rey Complex Figure on day 30. Overall, cognitive dysfunction was seen in 22 patients (28%) in the CEA group on day 1 and in 11 (23%) of 48 patients on day 30. CONCLUSIONS: Subtle cognitive decline following CEA occurs and persists for at least several weeks after surgery. This decline was absent in a control group.

Failure of intraoperative jugular bulb S-100B and neuron-specific enolase sampling to predict cognitive injury after carotid endarterectomy.

OBJECTIVE: Cognitive decline occurs in 25% of patients after carotid endarterectomy (CEA). Elevated serum concentrations of S-100B and neuron-specific enolase (NSE) occur after stroke, and serum S-100B levels at 24 hours are associated with clinical outcome after both stroke and CEA. We hypothesized that we could detect acute elevations in serum levels of these markers obtained intraoperatively from the jugular bulb (JB) and that these elevations would predict cognitive dysfunction postoperatively as measured by neuropsychometric test performance. METHODS: Forty-three patients scheduled for elective CEA were assessed with a battery of neuropsychometric tests before and 1 day after surgery. Before the carotid artery was clamped, a 6-French Fogarty catheter was inserted into the facial vein and threaded 6 cm rostrally into the JB. Serum samples were withdrawn from this catheter and simultaneously from a radial arterial catheter (A-line) at three time points: before clamping, 15 minutes into clamping, and after unclamping the carotid artery. Concentrations between groups were compared by analysis of variance and paired t tests. RESULTS: Total deficit scores were significantly worse in 13 (30%) of the 43 patients 1 day after surgery. There was a trend toward elevations in JB concentrations of S-100B relative to A-line levels 15 minutes after cross-clamping (11% elevation, P = 0.079, paired t test). In addition, 15 minutes after clamping of the carotid artery, levels of S-100B from the JB were significantly elevated compared with levels at baseline (P = 0.040, one-way analysis of variance). No significant changes were found between any time point in levels of S-100B from the A-line blood or of NSE from either the JB or the A-line. Subtle cognitive decline after CEA was not correlated with intraoperative levels of S-100B or NSE, but there was a weak, statistically nonsignificant, association between a rise in 15-minute S-100B levels and cognitive injury that was not seen with JB samples. CONCLUSION: Although intraoperative levels of S-100B and NSE from the JB failed to predict cognitive injury, carotid cross-clamping, independent of injury, seems to be associated with early elevations in S-100B.

The centennial of the Neurological Institute of New York and its department of neurological surgery, 1909-2009: a commemorative pictorial essay.

This presentation is a succinct pictorial essay reviewing the history of the Neurological Institute of New York through the succession of its Chairmen of Neurosurgery over the past 100 years.

Simulation in neurosurgery: a review of computer-based simulation environments and their surgical applications.

BACKGROUND: Computer-based surgical simulators create a no-risk virtual environment where surgeons can develop and refine skills through harmless repetition. These applications may be of particular benefit to neurosurgeons, as the vulnerability of nervous tissue limits the margin for error. The rapid progression of computer-processing capabilities in recent years has led to the development of more sophisticated and realistic neurosurgery simulators. OBJECTIVE: To catalogue the most salient of these advances and characterize our current effort to create a spine surgery simulator. METHODS: An extensive search of the databases Ovid-MEDLINE, PubMed, and Google Scholar was conducted. Search terms included, but were not limited to: neurosurgery combined with simulation, virtual reality, haptics, and 3-dimensional imaging. RESULTS: A survey of the literature reveals that surgical simulators are evolving from platforms used for preoperative planning and anatomic education into programs that aim to simulate essential components of key neurosurgical procedures. This evolution is predicated upon the advancement of 3 main components of simulation: graphics/volume rendering, model behavior/tissue deformation, and haptic feedback. CONCLUSION: The computational burden created by the integration of these complex components often limits the fluidity of real-time interactive simulators. Although haptic interfaces have become increasingly sophisticated, the production of realistic tactile sensory feedback remains a formidable and costly challenge. The rate of future progress may be contingent upon international collaboration between research groups and the establishment of common simulation platforms. Given current limitations, the most potential for growth lies in the innovative design of models that expand the procedural applications of neurosurgery simulation environments.

Neuropsychological dysfunction in the absence of structural evidence for cerebral ischemia after uncomplicated carotid endarterectomy.

OBJECTIVE: Neurocognitive dysfunction has been shown to occur in roughly 25% of patients undergoing carotid endarterectomy (CEA). Despite this, little is known about the mechanism of this injury. Recently, several groups have shown that new diffusion weighted imaging (DWI)-positive lesions are seen in 20% of patients undergoing CEA. We investigated to what degree neurocognitive dysfunction was associated with new DWI lesions. METHODS: Thirty-four consecutive patients undergoing CEA were subjected to pre- and postoperative cognitive evaluation with a battery of neuropsychological tests. Postoperative magnetic resonance imaging was performed in all patients within 24 hours of surgery. Lesions that showed high signal on DWI and restricted diffusion on apparent diffusion coefficient maps but no abnormal high signal on the fluid-attenuated inversion recovery images were considered hyperacute. RESULTS: Cognitive dysfunction was seen in eight (24%) patients. New hyperacute DWI lesions were seen in three (9%). Only one (13%) of the patients with cognitive dysfunction had a new DWI lesion. Two thirds of the new DWI lesions occurred in the absence of cognitive deterioration. Patients with cognitive dysfunction had significantly longer carotid cross-clamp times. CONCLUSION: Neurocognitive dysfunction after CEA does not seem to be associated with new DWI positive lesions.