Use of computerized cerebral tomography in selection of patients for elective and urgent carotid endarterectomy.

The charts of 181 patients who underwent computerized cerebral tomography (CCT) prior to carotid endarterectomy were reviewed. Findings on cerebral tomography were correlated with clinical presentation, frequency of intraoperative changes in the electroencephalogram (EEG), and occurrence of postoperative neurologic deficits. In the elective group (154 patients), while there was a significant (p less than 0.001) increase of positive ipsilateral CCT findings in stroke patients, 36% of patients with clinical stroke had a negative CCT scan and 21% of patients who were clinically asymptomatic had a positive CCT scan. Results of CCT did not correlate with the incidence of EEG changes (p greater than 0.2) or postoperative stroke rate (3.2%) (p greater than 0.5). Results of urgent carotid endarterectomy were directly related to the findings on preoperative CCT scan. A negative CCT scan was associated with clinical improvement in 88% of patients, one case of neurologic deterioration (5.8%) and no mortality (p less than 0.05). Only 50% of patients operated on acutely with a positive CCT scan showed neurologic improvement while there was a 40% increase in neurologic morbidity and 10% mortality in this group (p less than 0.01). CCT plays a limited role in the preoperative evaluation of patients with clear-cut clinical evidence of thrombo-embolic stroke or transient cerebral ischemia. Findings on CCT scan were of no help prognostically in selecting patients for elective carotid endarterectomy. In contrast, CCT scans have been extremely helpful in planning therapy for patients with acute neurologic problems and evidence of significant extracranial vascular disease.     

Cerebral protection during carotid endarterectomy

BACKGROUND: Perioperative stroke rates with carotid endarterectomy are 3.4% for asymptomatic and 5.2% for symptomatic patients. Several methods are used to limit perioperative stroke. METHODS: A retrospective chart review of consecutive carotid endarterectomies from January 1, 2000 to February, 28, 2003, was performed. Data were collected on patient demographics, operative procedure, intraoperative monitoring, and outcome. Comparative analysis of intraoperative monitoring and outcome was performed. RESULTS: Two hundred twenty-nine patients underwent 251 carotid endarterectomies. In 196 procedures decision to shunt was based on intraoperative monitoring, 129 by electroencephalogram (EEG), and 67 by stump pressures. Sixteen neurologic events occurred perioperatively, one transient ischemic attack and 15 strokes. The EEG group had 12 strokes, with a 38% event rate in procedures with EEG changes without shunting. The stump pressure group had one stroke. Stroke rate for intraoperative EEG monitoring was elevated (P = 0.02). CONCLUSIONS: Intraoperative EEG based decision to shunt may not be as effective as other methods for prevention of perioperative neurologic events. When EEG changes occur, shunting is necessary.     

Optimal cerebral monitoring during carotid endarterectomy: neurologic response under local anesthesia

A prospective series of carotid endarterectomies were performed with patients given local anesthesia in an attempt to determine the efficacy of intraoperative EEG monitoring and/or stump pressure measurements in predicting the need for carotid shunting. Carotid artery stump pressure was measured and EEG changes noted; however, neither low stump pressure nor EEG changes influenced the decision for shunt insertion. A shunt was only used if a neurologic deficit developed during carotid clamping. A total of 134 carotid endarterectomies were done in 121 patients. Sixty-six patients were men and 55 were women with ages ranging from 41 to 88 years. Indications included transient ischemic attacks in 57 (43%), prior stroke in 25 (19%), vertebrobasilar symptoms in nine (6%), and asymptomatic patients with high-grade stenosis, 43 (32%). Thirteen patients (9.7%) developed neurologic deficits following carotid clamping and had shunts inserted. All deficits cleared following shunt insertion. Nine of the 13 had EEG changes, but in four, EEGs were unchanged despite the occurrence of clear-cut neurologic changes. Stump pressure in the 13 patients ranged from 14 to 78 mm Hg. Ten were greater than 24 mm Hg and three were more than 50 mm Hg. In 121 operations no neurologic deficits occurred during carotid clamping and no shunts were inserted. In 13 of these operations, significant EEG changes were noted. Stump pressures in these 13 with EEG changes ranged from 15 to 120 mm Hg. In seven, stump pressure was greater than 50 mm Hg. There were no deaths in the series. Two (1.5%) temporary and one (0.7%) permanent postoperative deficits occurred.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cerebral complications associated with selective perfusion of the arch vessels

BACKGROUND: Few studies have determined risk factors for postoperative cerebral complications associated with surgery of the aortic arch using selective cerebral perfusion. METHODS: Between November 1992 and December 1998, 113 patients underwent aortic arch repair combined with selective cerebral perfusion. For each patient, three arch vessels were perfused using a single roller pump at a rectal temperature of 23 degrees C. RESULTS: Among the 108 patients who underwent postoperative neurologic assessment, 25 patients (23%) suffered from cerebral complications. Five patients (5%) suffered from transient neurologic disturbance and 17 patients (16%) suffered from stroke, and 7 patients (7%) of the preceding 17 patients had residual neurologic disturbance upon discharge. Three patients (3%) with either preoperative coma (n = 1) or post bypass cardiac arrest (n = 2) sustained severe global cerebral dysfunction. The occurrence of cerebral complications was not related to cerebral perfusion time. Independent risk factors for cerebral complications included a history of cerebrovascular disease, perioperative shock, distal anastomosis below the left pulmonary artery, malperfusion of extremities, and older age (> 60 years). CONCLUSIONS: Although high-level brain function was well preserved in most patients, the incidence of stroke when using current selective cerebral perfusion techniques is still high.     

Determining criteria for shunt placement during carotid endarterectomy. EEG versus back pressure

EEG monitoring and carotid back pressure were performed on 100 patients undergoing elective carotid endarterectomy. Shunts were inserted selectively in those patients who showed change in EEG after a trial period of carotid clamping (15%). No patient in the series awoke with a neurologic deficit. Back pressures were significantly lower in the shunted group and these pressures roughly correlated with EEG changes. Only one patient with a back pressure of greater than 40 mmHg had EEG changes and this patient had a recent mild stroke. EEG changes were most frequent in patients with contralateral carotid occlusions and in asymptomatic significant stenoses. EEG is a more discriminating indicator for shunt insertion than back pressure, although a pressure greater than 40 mmHg is safe in patients without recent stroke.     

Early carotid endarterectomy in patients with small,fixed neurologic deficits

Patients who have sustained a large hemispheric stroke are not candidates for early carotid endarterectomy, but there is less agreement regarding the role of carotid endarterectomy in patients with small, fixed neurologic deficits. Accepted practice in many centers is to wait 4 to 6 weeks after the onset of the deficit before proceeding with carotid endarterectomy because of the fear that early revascularization will increase the size of the infarct. Earlier endarterectomy, however, in patients with significant residual ipsilateral carotid territory at risk may prevent repeated infarctions. For the past 5 years our approach to patients with a small stable stroke and significant stenosis (>75%) has been prompt ipsilateral endarterectomy. Of the 337 carotid endarterectomies at our institution since 1979, a subset of 28 patients with hemodynamically significant carotid lesions presented with a small, fixed stroke. The period of time between the appearance of the stroke and carotid endarterectomy averaged 11 days, but 53% of patients were operated on within 7 days of the onset of symptoms. Selective shunting based on intraoperative EEG monitoring was utilized and 40% of the 28 patients required shunts. Operative mortality consisted of one death from a pulmonary embolus, and no patient sustained a new postoperative deficit. Long-term follow-up was available for 96% of patients over a mean of 2 years. During this time two new neurologic events occurred: one fatal stroke and one transient deficit. This experience indicates that patients with small, fixed neurologic deficits who continue to have carotid territory at risk may safely undergo carotid endarterectomy without waiting 4 to 6 weeks. (J VASC SURG 1984;1:795-799.)     

Prospective evaluation of electroencephalography, carotid artery stump pressure, and neurologic changes during 314 consecutive carotid endarterectomies performed in awake patients

OBJECTIVE: This study attempted to correlate neurologic changes in awake patients undergoing carotid endarterectomy (CEA) under cervical block anesthesia (CBA) with electroencephalography (EEG) and measurement of carotid artery stump pressure (SP). METHODS: Continuous EEG and SP monitoring was measured prospectively in 314 consecutive patients undergoing CEA between April 1, 2003, and July 30, 2006, under CBA. Indications for CEA were asymptomatic 70% to 99% internal carotid artery stenosis in 242 (77.1%), transient ischemic attacks (including transient monocular blindness) in 45 (14.3%), and prior stroke in 27 (8.6%). Mean common carotid artery pressure before clamping, mean SP after carotid clamping, and intraarterial pressure were continuously monitored in all patients. An indwelling shunt was placed when neurologic events (contralateral motor weakness, aphasia, loss of consciousness, or seizures) occurred, regardless of SP or EEG changes. RESULTS: Shunt placement was necessary because of neurologic changes in 10% (32/314) of all CEAs performed under CBA. Only 3 patients (1.4%) of 216 required shunt placement if SP was 50 mm Hg or more, vs 29 (29.6%) of 98 if SP was less than 50 mm Hg (P < .00001; sensitivity, 29.8%; specificity, 98.6%). In patients with SP of 40 mm Hg or more, 7 (2.6%) of 270 required shunt placement, vs 25 (56.8%) of 44 if SP was less than 40 mm Hg (P < .00001; sensitivity, 56.8%; specificity, 97.4%). Ischemic EEG changes were observed in 19 (59.4%) of 32 patients (false-negative rate, 40.6%) requiring shunt placement under CBA. Three patients had false-positive EEG results and did not require shunt placement (false-positive rate, 1.0%). The perioperative stroke/death rate was 4 (1.2%) in 314. All strokes occurred after surgery and were unrelated to cerebral ischemia or lack of shunt placement. CONCLUSIONS: Ten percent of patients required a shunt placement during CEA under CBA. Shunt placement was necessary in 56.8% of patients with SP less than 40 mm Hg. EEG identified cerebral ischemia in only 59.4% of patients needing shunt placement, with a false-positive rate of 1.0% and a false-negative rate of 40.6%. Both SP and EEG as a guide to shunt placement have poor sensitivity. Intraoperative monitoring of the awake patients under regional anesthesia (CBA) is the most sensitive and specific method to identify patients requiring shunt placement.     

Cerebral oximetry in patients undergoing carotid endarterectomy: preliminary results

Carotid endarterectomy (CEA) is an appropriate treatment for carotid occlusive disease. The risk of stroke during CEA ranges from 1.1% to 7.5%. Shunting is usually advised when severe ischemia during cross-clamping of the internal carotid artery is suspected. Routine use of an intraluminal shunt may increase the perioperative stroke rate. Popular and well documented methods of neurologic monitoring for ischemia during general anesthesia are electroencephalography (EEG) and transcranial Doppler ultrasonography (TCD) of the middle cerebral artery. The purpose of this prospective study was to compare cerebral oximetry using near infrared spectrophotometry (NIRS) with EEG and TCD. Preliminary data on 14 patients scheduled for elective carotid endarterectomy were included and a literature search was performed to correlate the findings. No postoperative neurologic events occurred. During carotid clamping there was a significant decrease in regional oxygen saturation (rSO2) but there was only a weak correlation with the decrease in mean Doppler flow (R = 0.74; P = 0.02) and no correlation with EEG changes (R = 0.49; P = 0.18). A useful rSO2 cut-off value predictive for cerebral ischemia could not be defined.     

Incidence of and risk factors for neurologic complications after heart transplantation

INTRODUCTION: Following heart transplantation (HT), neurologic complications occur in 50% to 70% of patients, mostly in the perioperative period. The objective of our study was to analyze the frequency and impact of factors related to the development of neurological complications after HT. MATERIALS AND METHODS: HT patients with survival greater than 1 month (November 1987 to May 2003) were included. Heart-lung transplants, retransplants, and pediatric patients were excluded. Neurologic complications were defined as a neurologic event requiring hospitalization or detected in the hospital. Groups included ischemic or hemorrhagic stroke, seizures, neurotoxicity or other complications (e.g., infections, headaches, Alzheimer's). RESULTS: We assessed 322 HT patients (87.6% men, 12.4% women) and grouped them according to the presence of neurologic complications during follow-up. There were no differences in the baseline characteristics between the two groups. Of patients the patients studied, 13.7% suffered a neurologic complication: ischemic stroke (3.5%), neurotoxicity (2.9%), seizures (1.9%), and other complications (1.6%). Only two cases of hemorrhagic stroke (0.6%) were observed. Associations with pretransplant risk factors included seizures with diabetes mellitus (OR, 6.54; 95% CI, 1.28 to 33.6, P = .024), seizures with renal failure (OR, 5.95; 95% CI, 1.03 to 34.3; P = .046), and ischemic stroke with prior valvular disease (OR, 4.96, 95% CI, 1.22 to 20.1; P = .045). Associations with pretransplant risk factors were neurologic complications with the number of infections (OR, 1.35, 95% CI, 1.05 to 1.73; P = .02). No differences were found in survival of patients with neurologic complications. CONCLUSIONS: The incidence of neurologic complications in our series was 13.7%. The most frequent neurologic complication was ischemic stroke. Valvular disease as the underlying disease was associated with ischemic stroke. Diabetes mellitus and renal failure were associated with seizures. The number of posttransplant infections was associated with neurologic complications. There were no differences in survival of patients with neurologic complications.     

Monitoring of electroencephalogram during open-heart surgery. A prospective analysis of 118 cases

The electroencephalogram (EEG) was prospectively analyzed in 118 consecutive open-heart procedures. In 96 patients (81%) the records were normal whereas in 22 patients (19%) the EEG showed slow wave activity and decreased electrical voltage. In 16 of these patients the EEG abnormality was transient or only of mild degree. In 10 of this group of patients the abnormality occurred with the institution of total cardiopulmonary bypass (CPB) and returned to normal within 2 minutes. In four other patients the abnormalities were mild, persisted to the end of the CPB, and then returned to normal; in two patients the EEG abnormalities developed in the last half of CPB and then returned to normal. In the remaining six patients the EEG was grossly abnormal. In one of these patients the abnormality was secondary to a previous stroke. In five patients, however, the EEG alerted the surgeon to an otherwise unsuspected poor cerebral blood flow. A serious neurologic insult was probably prevented by identifying and correcting the mechanical cause.     

EEG Changes during Awake Carotid Endarterectomy

To determine the reason for differing shunt rates based on electroencephalographic (EEG) and neurologic changes during general and regional anesthetic, respectively, we compared simultaneous EEG tracings and neurologic status in 135 patients undergoing carotid endarterectomy (CEA) under cervical block over a 30-month period. The decision to shunt in these patients was made on the basis of neurologic changes only irrespective of EEG findings. This group was then compared to the 288 patients undergoing CEA under general anesthetic with EEG monitoring over the same period. EEG changes occurred in 7.4% of awake patients and 15.3% of asleep patients (p <0.03). The rates of ipsilateral hemispheric changes were similar, but no awake patient manifested global EEG changes with clamping while 3.5% of patients under general anesthesia did (p <0.04). Global, but not hemispheric, changes were correlated with systolic blood pressure variability during clamping. This implies that global EEG changes in anesthetized patients may be the result of the anesthetic technique itself, and that cervical block may in fact be cerebroprotective.     

Patients with moderate to severe strokes (NIHSS score >10) undergoing urgent carotid interventions within 48 hours have worse functional outcomes

ObjectiveIncreasing evidence suggests that urgent carotid intervention after a nondisabling stroke is safe. However, the functional outcome of such patients has not been quantified for various degrees of stroke. We aimed to determine whether increased presenting stroke severity and timing to intervention are associated with poor functional outcomes in patients undergoing urgent carotid endarterectomy (CEA) or carotid artery stenting (CAS) after an acute transient ischemic attack or stroke.MethodsWe reviewed all urgent carotid interventions from January 2013 through April 2017 at a single tertiary referral center. Preoperative variables analyzed included admission stroke severity, calculated by National Institutes of Health Stroke Scale (NIHSS). The primary end point was the patient's neurologic functional independence at discharge, quantified by the modified Rankin scale (mRS) score (≤2, functionally independent; ≥3, dependent). Primary complications were defined as new or worsened stroke, intracranial hemorrhage, and death.ResultsA total of 120 urgent carotid interventions (CEA, n = 96; CAS, n = 22; 1 CEA with middle cerebral artery aspiration thrombectomy and 1 carotid embolectomy) were performed. Bivariate analysis demonstrated a correlation between admission NIHSS score and mRS score when patients were divided into groups with an admission NIHSS score ≤10 and >10 (P = .0029). Patients presenting with larger strokes (NIHSS score >10) were 3.4 times more likely (95% confidence interval [CI], 1.2-9.6; P = .024) to have functional dependence (mRS score ≥3) at discharge than patients presenting with minor to moderate strokes (NIHSS score ≤10). Patients undergoing CEA or CAS before 48 hours were also associated with a worse discharge mRS score compared with those undergoing carotid interventions after 48 hours (odds ratio, 3.5; 95% CI, 1.4-8.7; P = .007). Even when emergent carotid interventions were excluded from the subgroup of patients undergoing CEA or CAS within 48 hours, discharge mRS correlated with time to procedure (days 1- 2 compared with >2 days). The odds of having discharge functional dependence (mRS score ≥3) were 3.4 times more likely for patients with the procedure performed at 1 to 2 days compared with >2 days (95% CI, 1.3-9.1; P = .014).ConclusionsUrgent carotid intervention performed in patients with moderate or severe strokes (NIHSS score >10) and before 48 hours is associated with functional dependence (mRS score ≥3) on hospital discharge. By demonstrating a clear correlation between admission NIHSS score and interval time to procedure with independent neurologic functional outcomes, these data aid in clinical decision-making for this high-risk subpopulation of patients who present with acute symptomatic carotid lesions.     

Carotid endarterectomy without a shunt: the control series

Nine hundred forty carotid endarterectomies were performed without the use of a temporary indwelling shunt. Six patients (0.6%) died, all from stroke; 17 other patients (1.8%) had another stroke, and 21 patients (2.2%) had temporary neurologic symptoms. Complete x-ray films detailing the opposite internal carotid artery and carotid artery back pressure were available for 783 operations. Correlation of stroke to back pressure, status of the contralateral internal carotid artery, preoperative neurologic deficit, and carotid clamp time was examined. Statistical analysis demonstrated significantly increased neurologic complications only if the systolic carotid back pressure was less than or equal to 50 mm Hg or the contralateral internal carotid artery was occluded. Analysis to determine if these factors were dependently related showed that when both a contralateral carotid occlusion and a carotid back pressure of less than or equal to 50 mm Hg coexisted (82 patients), the rate of permanent deficit was 11.0% compared with 2.8% when either factor was singly present and 0.9% when neither factor was present. No statistical difference exists between the group with only a single factor and those with neither factor. When a temporary shunt is not used during carotid endarterectomy, the risk of neurologic complication is increased if both a contralateral internal carotid artery occlusion and a carotid back pressure of less than or equal to 50 mm Hg coexist. The use of a shunt in this patient population may be beneficial.     

Early carotid endarterectomy after acute stroke

PURPOSE: Carotid endarterectomy (CEA) after acute stroke is generally delayed 6 to 8 weeks because of fear of stroke progression. This delay can result in an interval stroke rate of 9% to 15%. We analyzed our results with CEA performed within 1 to 4 weeks of stroke. METHODS: Records for all patients undergoing CEA after stroke between 1980 and 2001 were analyzed. Perioperative evaluation included carotid duplex scanning or angiography, and head computed tomography or magnetic resonance imaging. All patients with nonworsening neurologic status, additional brain territory at risk for recurrent stroke, and severe ipsilateral carotid stenosis underwent CEA. Patients were grouped according to time of CEA after stroke: group 1, first week; group 2, second week; group 3, third week; group 4, fourth week. Statistical analysis was performed with the chi(2) test, logistic regression, and analysis of variance. RESULTS: Two hundred twenty-eight patients underwent CEA within 1 to 4 weeks of stroke. Perioperative permanent neurologic deficits occurred in 2.8% of patients in group 1 (72 procedures), 3.4% of patients in group 2 (59 procedures), 3.4% of patients in group 3 (29 procedures), and 2.6% of patients in group 4 (78 procedures). There was no relationship between location or size of preoperative infarct and time of surgery. Only preoperative infarct size correlated with probability of neurologic deficit after CEA (P <.05). CONCLUSION: Incidence of postoperative stroke exacerbation is similar at all intervals. The results are within acceptable limits for treatment of symptomatic carotid stenosis. CEA may be performed within 1 month of stroke with similar results at all intervals during this period.     

Screening Carotid Ultrasonography and Risk Factors for Stroke in Coronary Artery Surgery Patients

Background. The role of noninvasive carotid artery screening in relation to other clinical variables in identifying patients at increased risk of stroke after coronary artery bypass grafting was examined.

Methods. Preoperative, intraoperative, and postoperative clinical data were prospectively collected for 1,835 consecutive patients undergoing first-time isolated coronary artery bypass grafting between March 1990 and July 1995, 1,279 of whom had screening carotid ultrasonography. All patients with postoperative neurologic events were identified and reviewed in detail. Average patient age was 65.3 years (range, 33 to 92 years), and 9.3% (171 patients) had a prior permanent stroke or transient ischemic attack. Hospital and 30-day mortality was 2.2% (41 patients). Forty-five patients (2.5%) had a transient or permanent postoperative neurologic event. The data were analyzed by stepwise logistic regression to determine the independent predictors of both significant carotid stenosis and stroke.

Results. On multivariate analysis, the clinical predictors of significant carotid stenosis were age (p < 0.0001), diabetes (p = 0.0123), female sex (p = 0.0026), left main coronary stenosis greater than 60% (p < 0.0001), prior stroke or transient ischemic attack (p = 0.0008), peripheral vascular disease (p = 0.0001), prior vascular operation (p = 0.0068), and smoking (p < 0.0001). When all variables were evaluated for those patients who underwent noninvasive carotid artery screening, the independent predictors of postoperative neurologic event were prior stroke or transient ischemic attack (p < 0.0001), peripheral vascular disease (p = 0.0037), postinfarction angina pectoris (p = 0.0319), postoperative atrial fibrillation (p = 0.0014), carotid stenosis greater than 50% (p = 0.0029), cardiopulmonary bypass time (p = 0.0006), significant aortic atherosclerosis (p = 0.0054), postoperative amrinone or epinephrine use (p = 0.0054), and left ventricular ejection fraction less than 0.30 (p = 0.0744).

Conclusions. The etiology of postoperative stroke is multifactorial. Selective use of carotid ultrasonography is of value in identifying patients who are at greater risk of postoperative stroke independent of other variables and should be considered before coronary artery bypass grafting, particularly in patients with a history of neurologic event or peripheral vascular disease.     

Neurologic complications in prostatic carcinoma

A review of 10 years experience with prostatic carcinoma was undertaken with a search for neurologic complications. An unusual case presenting with symptoms of hemiplegia is reviewed. Of 154 charts, 90 provided adequate clinical information for complete analysis. Nineteen cases with neurologic complications were found and were restricted entirely to advanced (stages C and D) disease. Thirty-seven percent of patients with advanced disease developed neurologic complications. The most frequent complaints were related to organic brain syndrome, paraplegia, and radioculopathy. Eight patients developed peripheral nerve or spinal cord injury related to metastatic disease. Five patients suffered metabolic or paraneoplastic complications; three patient's symptoms related to central or epidural metastases and two patients developed neurologic symptoms related to complications of therapy. All neurologic symptoms improved given appropriate diagnosis and treatment. A brief review of the literature is included emphasizing the diverse nature of neurologic complications in this common neoplasm.     

Computed electroencephalographic topographic brain mapping. A new and accurate monitor of cerebral circulation and function for patients having carotid endarterectomy

To determine the usefulness of computed electroencephalographic (EEG) topographic (CET) brain mapping to monitor neurologic function during carotid endarterectomy (CEA), 46 consecutive patients having CEA were monitored preoperatively, intraoperatively, and immediately postoperatively by CET brain mapping and simultaneous 16-lead EEG. Preoperative studies revealed that 7 of 16 asymptomatic patients, 5 of 11 patients with amaurosis fugax, and 8 of 12 patients with transient ischemic attacks (TIAs) had abnormal CET brain mapping suggestive of previous subclinical stroke. EEG was abnormal in only 8 of the 20 patients with abnormal CET brain mapping. Intraoperatively during carotid cross-clamping, ischemic changes were seen on CET brain mapping in 23 patients whereas EEG detected these changes in only 13 patients. Ischemic changes detected by intraoperative CET brain mapping were more likely to occur in patients with previous stroke (six of seven) than in patients without previous stroke (17 of 39), p less than 0.05. Patients with changes detected by intraoperative CET brain mapping had an average carotid back-pressure of 38 mm Hg, in contrast to 57 mm Hg for patients without CET brain mapping changes, p less than 0.05. After endarterectomy, CET brain mapping revealed new ischemic changes in one patient who awoke with a mild stroke and in one patient who had TIAs and amaurosis fugax within 6 hours of surgery. We conclude that CET brain mapping is a sensitive, accurate, and useful noninvasive monitor of cerebral circulation and function for patients having CEA.(ABSTRACT TRUNCATED AT 250 WORDS)     

缺血性脑卒中的CT、TCD、EEG、BEAM检测的分析对比

目的探讨CT、TCD、EEG、BEAM检测在缺血性脑卒中诊断中的临床意义.方法对CT确诊缺血性脑卒中的142例住院病人的CT、TCD、EEG、BEAM检测进行对比分析. 结果对缺血性脑卒中检测的异常率分别为CT100(%),TCD79.6(%),EEC71.1(%),BEAM65.5(%).CT对缺血性脑卒中早期诊断的异常率:24小时内为25.3%,72小时内为51.7%,与TCD、EEG、BEAM比较有显著性差异.结论TCD不能直接判断脑卒中的特性,可以结合CT结果来判断脑内血管的供血状况及WILL'S环的功能,评估脑血管的潜在代偿功能.EEG/BEAM反应了脑组织局部的结构损害及相应功能区的神经元活动的影响程度,且可动态观察:与CT显示的影像学改变要经过结构改变的病理过程相比较,在脑卒中急性期的诊断和病情发展的监测方面有明显的优越性.     

Comparison of simultaneous electroencephalographic and mental status monitoring during carotid endarterectomy with regional anesthesia

Purpose: This study examines the accuracy of intraoperative electroencephalographic (EEG) monitoring for the detection of cerebral ischemia by comparing EEG with simultaneous mental status evaluation (MSE) during carotid endarterectomy in awake patients. Methods: Between 1994 and 1997, 208 consecutive carotid endarterectomies were prospectively evaluated for cerebral function during surgery with simultaneous MSE and EEG monitoring. Regional anesthesia (RA), which consisted of superficial cervical block, was chosen preferentially in 75% of the cases, with general anesthesia (GA) reserved for the patients who did not fulfill the criteria for RA. When available, 8-channel EEG monitoring was performed (59% with RA and 55% with GA). Results: The EEG was a reliable predictor in comparison with MSE in most but not all cases of cerebral ischemia. Significant neurologic changes were noted using MSE in 4 of 89 patients (4.5%) that were not detected using EEG (false negative results). Conversely, 6 of 89 cases (6.7%) showed unilateral slowing without associated changes in MSE (false positive results). For the awake patients, 21 of 150 cases (14%) showed MSE changes that required a shunt. By contrast, 9 of 32 GA cases (28%) showed EEG changes that would have led to shunting (P = NS). In the RA group, there were no strokes versus 3 of 58 cases (5.2%) with strokes in the GA group. Two of 150 cases (0.1%) had transient ischemic attacks in the RA group. There was 1 myocardial infarction in the GA group; no deaths occurred in this series. Conclusion: EEG monitoring yielded a significant number of false positive (6.7%) and false negative (4.5%) results in the detection of neurologic deficits when compared with MSE in the awake patients. In this series, the preferential use of RA resulted in less shunt use and was possibly associated with a lower stroke rate. (J Vasc Surg 1998;28:1014-23.)     

Timing of carotid endarterectomy after acute stroke

An arbitrary delay of at least 6 weeks before performing carotid endarterectomy after acute stroke has been recommended based on anecdotal reports. This prolonged interval may increase the danger of recurrent neurologic deficit before surgery. From September 1978 to September 1988, carotid endarterectomy was performed on 140 patients at variable intervals after stroke. Eleven patients had temporary stroke, which left 129 patients with neurologic symptoms that persisted for 3 weeks or had a cortical infarct on CT scanning. A prospective therapeutic protocol was applied to 82 patients admitted with acute stroke. They were observed until neurologic recovery reached a plateau, based on clinical observation by a neurologist, before performing angiography and carotid endarterectomy (group I). Forty-seven patients were not seen until after recovery from stroke was established (group II). At initial presentation, the severity of neurologic deficit was classified as mild, moderate, or severe in 31%, 58%, and 11%, respectively. Recovery before operation was registered as complete in 11%, mild residual in 66%, moderate residual in 21%, and severe residual in 2%. Group I patients (n = 82, 64%) were operated on within 6 weeks of stroke and group II (n = 47, 36%) were operated on at varying times after 6 weeks. No significant difference was found in the incidence of cerebrovascular events (1.2% vs 4.2%) and deaths (1.3% vs 2.1%) between groups I and II with respect to the timing of carotid endarterectomy, and no significant difference was found between patients operated on at 2, 4, 6, or more than 6 weeks after stroke.(ABSTRACT TRUNCATED AT 250 WORDS)