Propofol versus sevoflurane anaesthesia: effect on cognitive decline and event-related potentials.

Postoperative cognitive dysfunction (POCD) is diagnosed in up to 30% patients after anaesthesia. The causative role of anaesthetic toxicity remains unclear. Using clinical tests, no clear-cut differences have been observed between anaesthetics so far. The aim of this trial was to compare the incidence of POCD diagnosed by a battery of neuropsychologic tests after propofol and sevoflurane anaesthesia. Secondary goal was to examine possible relationship between POCD positivity and changes in auditory event-related potentials (ERPs). Sixty patients undergoing lumbar discectomy were prospectively randomized to receive depth-controlled sevoflurane (SEVO) or propofol (PROP) based anaesthesia. The neuropsychological examination and auditory event-related potentials (N1, P3a and P3b components) recording was performed preoperatively and on days 1, 6 and 42 after surgery. POCD was defined as a decline of more than one standard deviation in three or more tests. In 43 patients (20 in PROP and 23 in SEVO group) all selected tests were performed and used for the evaluation. POCD was present in 48%/60%, 18%/20% and 17%/11% (SEVO/PROP) of patients on days 1, 6 and 42 after surgery, with no significant intergroup difference. Among neuropsychologic tests, the most significant decline was observed in Semantic Verbal Fluency and Letter-Number Sequencing Test scores, congruently in both groups on days 1 and 6, with full recovery on the last control. Transient deteriorations in other tests were observed as well. No association of POCD positivity and ERPs changes was found, although long-term modifications of P3a and P3b components were observed, mainly in SEVO group. In our study, sevoflurane and propofol anaesthesia was associated with the similar incidence of POCD. Cognitive decline, mainly affecting executive functions, was temporary in most of the patients. Prolonged ERPs alterations after the anaesthesia seem not to have any relationship with the impairment registered by the neuropsychological examination and may represent subclinical changes.

The impact of general versus local anesthesia on early subclinical cognitive function following carotid endarterectomy evaluated using P3 event-related potentials.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is detected in 25% of patients undergoing carotid endarterectomy (CEA). The mechanism of POCD is poorly understood, but it is believed that general anesthesia (GA) itself may contribute significantly to POCD. The aim of our prospective study was to compare, with the aid of event-related potentials, the impact of general anesthesia (GA) and local anesthesia (LA) on POCD in patients undergoing CEA. METHODS: Sixty patients were included in this study and were divided into two groups: CEA was performed in 30 patients placed under GA (total intravenous anesthesia), herein the GA group, while 30 patients underwent CEA under LA (cervical plexus block), herein LA group. Cognitive outcome was assessed with the use of auditory event-related potentials (ERPs), P3 response. The measurements were taken before surgery (pre-op) and on the first (1.post-op) and the sixth postoperative days (6.post-op). RESULTS: Preoperative cognitive functions did not differ significantly between the two groups. A significant decrease in P3 amplitude was found on the first postoperative day (1.post-op) in the GA group (p = 0.0005), but normalization of P3 amplitude was detected at the second postoperative measurement (6.post-op). The patients operated on under local anesthesia (LA group) showed stable P3 amplitudes in all three measurements. No significant changes in P3 latencies were observed in either group. There were no significant differences between the two groups regarding demographic characteristics, preoperative and postoperative clinical condition, percentage significance of carotid artery stenosis, duration of carotid cross-clamping or in the frequency of shunt use (zero frequency for both groups). CONCLUSIONS: Our study showed that general anesthesia, used for patients undergoing CEA, negatively influenced cognitive function during the immediate period after surgery (the first postoperative day). However, by the sixth postoperative day, this cognitive impairment was no longer being detected. POCD occurring shortly after carotid endarterectomy is the result of general anesthesia, which is probably an independent evoking factor in itself. The cognitive deficit recorded only during the immediate postoperative period, is not a negative effect of GA but merely a side-effect and thus GA should not be considered inferior to LA for use during CEA.

[The impact of neuroprotection on brain metabolism during carotid endarterectomy]. / Vliv neuroprotekce na mozkové metabolické parametry pri karotické endarterektomii.

BACKGROUND: The primary objective of this study was to evaluate the impact of neuroprotection, administered during carotid endarterectomy, on brain metabolism. The secondary objective was to assess the impact on clinical outcome of the resulting changes to brain metabolism. METHODS: A total of 35 patients underwent carotid endarterectomy with prophylactic combined neuroprotection (Sendai cocktail: Manitol, Phenhydan, Solumedrol, Tokoferol; Cerebrolysin; fraction of inspired oxygen (FiO2) = 1, middle arterial pressure (MAP) = 100 mm Hg, total intravenous anaesthesia--TIVA). The influence of neuroprotection on brain metabolism (S100B, glycaemia, lactate, pH, jugular vein bulb oxygen saturation--SvjO2) was evaluated. Metabolic parameters were acquired from the jugular bulb during surgery, just before unclamping of the vessel. The clinical outcome was evaluated by NIHSS (National Institutes of Health Stroke Scale). There were 35 patients in the control group who where operated on without any neuroprotection. The results from both groups of patients were compared and statistically analyzed. RESULTS: Postoperative NIHSS did not change in any patients in either group. An intraoperative shunt was not inserted in any patients in either group. In the group with neuroprotection there were significantly higher levels of S100B (median 0.117 vs. 0.088; p < 0.0182), lactate (median 1.92 vs. 1.020; p < 0.0006), glycaemia (median 9.5 vs. 8.2; p < 0.0243), and SvjO2 (median 0.79 vs. 0.65; p < 0.0001). There were no postoperative changes to NIHSS in either group. CONCLUSIONS: Neuroprotection administered before carotid endarterectomy influences some parameters of brain metabolism both positively and negatively, but with no impact on clinical outcome.

Patient Satisfaction with General versus Local Anesthesia during Carotid Endarterectomy.

BACKGROUND AND STUDY AIMS: Both general and local anesthesia are used in our department for carotid endarterectomy (CEA). The decision as to which anesthetic technique to use during surgery is made individually. The aim of our study was to evaluate patient satisfaction and preference with the anesthesia type used. MATERIAL AND METHODS: The satisfaction of a group of 205 patients with regard to anesthesia used and their future preferences were evaluated prospectively through a questionnaire. The reasons for dissatisfaction were assessed. RESULTS: CEA was performed under general anesthesia (GA) in 159 cases (77.6%) and under local anesthesia (LA) in 46 cases (22.4%). In the GA group, 148 patients (93.1%) were satisfied; 30 patients (65.2%) in the LA group were satisfied (p < 0.0001). The reason for dissatisfaction with GA were postoperative nausea and vomiting (7 patients), postoperative psychological alteration (3), and fear of GA (1). The reasons for dissatisfaction with LA were intraoperative pain (9 patients), intraoperative discomfort and stress (5), and intraoperative breathing problems (2). Of the GA group, 154 (96.9%) patients would prefer GA again, and of the LA group, 28 (60.9%) patients would prefer LA if operated on again (p < 0.0001). Overall, 172 patients (83.9%) would prefer GA in the future, and 33 patients (16.1%) would prefer LA. CONCLUSION: Overall patient satisfaction with CEA performed under both GA and LA is high. Nevertheless, in the GA group, patient satisfaction and future preference were significantly higher. Both GA and LA have advantages and disadvantages for CEA. An optimal approach is to make use of both anesthetic techniques based on their individual indications and patient preference.

Subject's own name as a novel in a MMN design: a combined ERP and PET study.

With a view to elaborating a clinical tool to assess cognitive functions in brain-damaged patients, we had previously displayed characteristic patterns of ERPs (32 electrodes) in awake healthy persons in response to their own name (SON) presented as a novel in a passive oddball paradigm. In the present combined ERP and PET study, in an attempt to identify brain correlates of duration MMN and response to SON uttered by a familiar (FV) or an unknown voice (NFV), we used a block design protocol as close as possible to the aforementioned SON protocol. ERP data showed robust duration MMN and novelty P3 in response to SON similar to our previous results. The PET technique did not allow true MMN generators to be disclosed, but blocks with duration deviants elicited an increase of activation in the right temporal pole as compared with the control condition with no deviants, supporting the hypothesis of right hemispheric dominance in early sound discrimination. For SON contrasts, robust cerebral blood flow activation present over temporal, frontal and parietal cortices, in the hippocampus and in the precuneus could be associated with speech, novelty and self-recognition processing. Familiar and unfamiliar voices activated the prefrontal cortex differently, suggesting different retrieval processes, although corresponding ERP responses could not be differentiated.

Cognitive impairment measured by event-related potentials during early and late postoperative period following intravenous or inhalation anaesthesia.

OBJECTIVE: This study investigated modification in cognitive function following inhalation (IA) and total intravenous (TIVA) anaesthesia measured using auditory ERPs (Event Related Potentials). METHODS: Auditory ERPs examination with N1, P3a and P3b component registration was carried out one day before surgery (D-1) and on the first (D+1), sixth (D+6) and 42nd (D+42) days after surgery. Results were compared between two anaesthetic groups. RESULTS: On D+1, N1 latency was increased in the IA group. A significant reduction was observed in amplitude of the P3a component on D+6, which persisted up to D+42 for both IA and TIVA groups. A reduction in the amplitude of P3b on D+1 with normalization by D+6 was found in both groups as well. CONCLUSIONS: Intravenous and inhalation anaesthesia lead to similar changes in cognitive function as determined by ERPs, both during the early and late postoperative periods. It cannot be clearly confirmed whether the observed effects are due to anaesthesia or other unmonitored perioperative factors. SIGNIFICANCE: Post anaesthetic changes represent a subclinical impairment; nevertheless, they represent a potential risk for subsequent development of cognitive difficulties.

Developmental coordination disorder in children - experimental work and data annotation.

Background: Developmental coordination disorder (DCD) is described as a motor skill disorder characterized by a marked impairment in the development of motor coordination abilities that significantly interferes with performance of daily activities and/or academic achievement. Since some electrophysiological studies suggest differences between children with/without motor development problems, we prepared an experimental protocol and performed electrophysiological experiments with the aim of making a step toward a possible diagnosis of this disorder using the event-related potentials (ERP) technique. The second aim is to properly annotate the obtained raw data with relevant metadata and promote their long-term sustainability. Results: The data from 32 school children (16 with possible DCD and 16 in the control group) were collected. Each dataset contains raw electroencephalography (EEG) data in the BrainVision format and provides sufficient metadata (such as age, gender, results of the motor test, and hearing thresholds) to allow other researchers to perform analysis. For each experiment, the percentage of ERP trials damaged by blinking artifacts was estimated. Furthermore, ERP trials were averaged across different participants and conditions, and the resulting plots are included in the manuscript. This should help researchers to estimate the usability of individual datasets for analysis. Conclusions: The aim of the whole project is to find out if it is possible to make any conclusions about DCD from EEG data obtained. For the purpose of further analysis, the data were collected and annotated respecting the current outcomes of the International Neuroinformatics Coordinating Facility Program on Standards for Data Sharing, the Task Force on Electrophysiology, and the group developing the Ontology for Experimental Neurophysiology. The data with metadata are stored in the EEG/ERP Portal.

Brain responses to a subject's own name uttered by a familiar voice.

Hearing one's own first name automatically elicits a robust electrophysiological response, even in conditions of reduced consciousness like sleep. In a search for objective clues to superior cognitive functions in comatose patients, we looked for an optimal auditory stimulation paradigm mobilizing a large population of neurons. Our hypothesis was that wider ERPs would be obtained in response to the subject's own name (SON) when a familiar person uttered it. In 15 healthy awake volunteers, we tested a passive oddball paradigm with three different novels presented with the same probability (P = 0.02): SON uttered by a familiar voice (FV) or by an unknown voice (NFV) and a non-vocal stimulus (NV) which preserved most of the physical characteristics of SON FV. ERP (32 electrodes) and scalp current density (SCD) maps were analyzed. SON appeared to generate more robust responses related to involuntary attention switching (MMN/N2b, novelty P3) than NV. When uttered by a familiar person, the SON elicited larger response amplitudes in the late phase of novelty P3 (after 300 ms). Most important differences were found in the late slow waves where two components could be temporally and spatially dissociated. A larger parietal component for FV than for NFV suggested deeper high-level processing, even if the subjects were not required to explicitly differentiate or recognize the voices. This passive protocol could therefore provide a valuable tool for clinicians to test residual superior cognitive functions in uncooperative patients.

Urgent extracranial-intracranial bypass in the treatment of acute hemodynamic ischemic stroke: case report.

Extracranial-intracranial (EC-IC) bypass surgery is performed to allow flow augmentation in selected cases of occlusive cerebrovascular disease. The majority of EC-IC bypasses are described as an elective procedure in the prevention of hemodynamic ischemic stroke. There is only limited and controversial experience of superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis performed under urgent circumstances as a treatment of acute cerebral ischemia. We describe a unique case of a 75-year-old patient presenting with acute progressive hemodynamic ischemia after carotid endarterectomy (CEA), which developed contralaterally to the performed CEA in the region of chronic internal carotid artery (ICA) occlusion. Urgent performance of a standard STA-MCA bypass rapidly improved the cerebral hemodynamic and had an excellent therapeutic effect. The patient had recovered completely within 4 weeks of surgery. The role of urgent EC-IC bypass for stroke treatment is discussed.