Awake Craniotomy For Tumor Resection Research Articles

AB073. Electrocorticography high-gamma dynamics during intraoperative hand movement mapping.

Intraoperative functional mapping for glioma resection often necessitates awake craniotomies, requiring active patient participation. This procedure presents challenges for both the surgical team and the patient. Thus, minimizing mapping time becomes crucial. Passive mapping utilizing electrocorticography (ECoG) presents a promising approach to reduce intraoperative mapping efforts via direct electrical stimulation. This study aims to identify an efficient mapping protocol for hand movement by optimizing mapping duration and localization accuracy. Three glioma patients (two males, one female) underwent awake craniotomy for tumor resection at Asahikawa Medical University Hospital and Kindai University in Osaka. Patients were maintained at a bispectral index (BIS) level above 90 to ensure wakefulness during mapping. Data were collected using a DC-coupled g.HIamp biosignal amplifier, digitized with 24-bit resolution at a minimum sampling rate of 1,200 Hz. Each session comprised ten runs, each lasting 250 seconds, consisting of a 12-second rest phase (baseline) followed by a 12-second grasping period containing ten grasping movements. High-gamma activity (HGA, 60-170 Hz) was recorded from ECoG locations on the pre- and postcentral gyrus. Locations exhibiting significant grasping-related HGA, with stronger responses during early trials within a run, were classified as "attenuated". Among 37 electrodes on the sensorimotor cortex, 16 exhibited significant HGA during grasping. Three locations demonstrated significant attenuation after three runs, with one location showing attenuation after the first three trials within a run. The observed attenuation effect of short-term repeated movements during intraoperative monitoring is relatively modest initially. However, as the number of repeated grasping blocks increases, the number of attenuated locations also rises. Consequently, minimizing overall mapping time, rather than reducing the number of tasks per block, is paramount. For statistical analysis, a minimum of 20 grasping trials (two runs of ten movements) or 48 seconds of motor mapping is recommended. Alternatively, a mapping protocol involving a third run or 30 grasping trials (72 seconds) may enhance data robustness. These preliminary findings, though based on a limited patient cohort, warrant confirmation and further investigation, particularly in epilepsy patients.

512 Mapping High Gamma Neural Signals in Hand Primary Somatosensory Cortex Using a Multi-Thousand Channel Platinum Nanorod Microelectrode Grid

INTRODUCTION: Neurological deficits secondary to pathologies such as stroke, tumor, trauma, and neurodegeneration lead to enduring disability for many patients. Therefore, the development of neurorestorative technologies utilizing brain computer interfaces (BCIs) is an important goal in applied neuroscience. The high-gamma electrocorticographic (ECoG) neural signals from surgically implanted brain electrodes can be used as an indirect proxy for neuronal spiking activity and local neuronal output, which has translated into an effective control signal for BCIs. Direct electrical stimulation (DES) of primary somatosensory cortex has been used to provide sensory feedback in bi-directional sensorimotor BCIs (BBCIs). METHODS: During an awake craniotomy for tumor resection, a PtNRGrid was placed over primary hand somatosensory cortex while touches were applied to the ipsilateral and contralateral hand and arm. RESULTS: Here, we demonstrate the mapping of the high gamma signal in single digit and individual carpal distribution. CONCLUSIONS: This is the first analysis of high gamma signal in human hand primary somatosensory cortex utilizing PtNRGrids.

High gamma activity distinguishes frontal cognitive control regions from adjacent cortical networks

Though the lateral frontal cortex is broadly implicated in cognitive control, functional MRI (fMRI) studies suggest fine-grained distinctions within this region. To examine this question electrophysiologically, we placed electrodes on the lateral frontal cortex in patients undergoing awake craniotomy for tumor resection. Patients performed verbal tasks with a manipulation of attentional switching, a canonical control demand. Power in the high gamma range (70–250 Hz) distinguished electrodes based on their location within a high-resolution fMRI network parcellation of the frontal lobe. Electrodes within the canonical fronto-parietal control network showed increased power in the switching condition, a result absent in electrodes within default mode, language and somato-motor networks. High gamma results contrasted with spatially distributed power decreases in the beta range (12–30 Hz). These results confirm the importance of fine-scale functional distinctions within the human frontal lobe, and pave the way for increased precision of functional mapping in tumor surgeries.

Awake Craniotomy without Invasive Blood Pressure Monitoring

To assess the safety of foregoing invasive monitoring in a select group of patients undergoing awake craniotomy for supratentorial tumor resection. Awake craniotomies were performed for tumor resection without invasive blood pressure monitoring when there was no preexisting cardiopulmonary indication as determined by the attending anesthesiologist according to institutional protocol. Noninvasive monitoring was performed every 3-5 minutes intraoperatively and then every 15 minutes in the recovery room for 4 hours before transfer to the ward. At a single tertiary care hospital, 74 consecutive awake surgeries were performed with noninvasive blood pressure monitoring. Among patients, 39 (52.7%) were male, 42 (83.8%) had infiltrative primary brain tumors, 2 (2.7%) had a history of coronary artery disease, 6 (8.1%) were diabetics, 10 (29.7%) were smokers, and 22 (29.7%) were on antihypertensive medications preoperatively. American Society of Anesthesiologists classification was I in 1.4% of patients, II in 36.4%, III in 60.8%, and IV in 1.4%. Intraoperative vasoactive medications were administered in 21 (28.4%) patients; 8 (38%) of these were on antihypertensive agents preoperatively. Vasodilators were administered in 13 (61.9%) patients, vasopressors were given in 6 (28.6%) patients, and both vasodilators and vasopressors were given in 2 (9.5%) patients. One patient experienced a lenticulostriate artery stroke intraoperatively, and 1 patient experienced atrial fibrillation 1 week postoperatively. There were no other perioperative anesthetic, hemorrhagic, renal, or cardiopulmonary complications. Intraoperative physiologic control and surgical site complication avoidance do not warrant routine invasive blood pressure monitoring during awake craniotomy for tumor resection.

Patient’s Acting on their Own Care: Medical Hypnosis for Perioperative Management in The Awake Craniotomy. Technical Report and Clinical Cases.

The patient as the custodian of their own care is a concept that has been evolving for several years and can help the patient to a better and quicker recovery. Medical Hypnosis (MH) assist the practitioner to reduce the patient’s pain and disorders and help the patient to understand, accept, and manage their situation. Recently, this technique has been increasingly used in awake surgery protocols. This paper describes three examples of the successful perioperative management of patients who benefited from an awake craniotomy for tumor resection with the aid of MH. Another case of a patient who had developed post-traumatic stress disorder (PTSD) after an operation without MH is also described.

High-Frequency Oscillations in Tumor-Related Epilepsy.

To define the patient characteristics, tumor characteristics, and clinical course of patients with primary brain tumors with high-frequency oscillations (HFOs) recorded on electrocorticography. Furthermore, we evaluated whether the presence of HFOs portends a greater risk of postoperative tumor-related epilepsy and whether the resection of HFO-generating tissue reduces likelihood of postoperative tumor-related epilepsy. This was a retrospective study of 35 patients undergoing awake craniotomy for tumor resection, all of whom underwent intraoperative electrocorticography. Electrocorticography data were reviewed to assess the presence of HFOs and determine their contact locations. The data were analyzed to determine whether HFO-generating tissue was included in the resection and relationship to postoperative seizure outcome. Seventeen patients (48.5%) were found to have HFOs. Very few patients (4 of 35, 11.4%) had sharp waves. Patients with and without HFOs did not significantly differ in demographics, presentation, tumor characteristics, or tumor molecular genetics. A history of seizures prior to resection was not associated with the presence of HFOs ( P = 0.62), although when patients had seizures during the same hospitalization as the resection, HFOs were more likely to be present ( P = 0.045). Extent of HFO resection was not associated with the likelihood of postoperative seizure freedom. Approximately half (48.5%) of patients undergoing resection for a primary brain tumor had HFOs. Although HFO resection was not shown to lead to improved seizure freedom, this study was limited by a small sample size, and further investigation into HFO resection and patient outcomes in this population is warranted.

Dexmedetomidine as adjunct in awake craniotomy - improvement or not?

Over the last decade, awake craniotomy for tumor resection has become a standard to maximize tumor resection and minimize the risk of permanent neurological deficits. Different techniques and medication regimes have been tested for this procedure. Until today there is no consensus on the optimal approach. Therefore, we investigated the effect of dexmedetomidine as an adjunct in awake cerebral tumor surgery and evaluated our improved technique. Data of patients who underwent awake craniotomy for tumor resection at our institution between 09/2006 and 05/2018 were retrospectively analyzed. All patients were kept awake after cortical mapping. After changing our standard anesthetic procedure from propofol/remifentanil alone to propofol/remifentanil and dexmedetomidine, we performed an evaluation of time to arousal, drug dosages, patients' cooperation and the occurrence of periprocedural adverse events. Eighty-four patients received propofol/remifentanil alone (SG). A further 17 patients additionally received dexmedetomidine following craniotomy in order to induce rapid arousal (DG). In the dexmedetomidine group a significantly reduced infusion time for propofol (169.2 ± 47.4 vs. 212.9 ± 63.3 minutes; P = 0.008) and non-significantly shorter time to arousal (12.0 [10.0/16.5] vs. 15.0 [10.0/20.0] minutes; P = 0.271) could be identified. In general, the overall procedure was very well tolerated by all patients. The asleep-awake technique is a well-accepted and safe procedure. It allows continuous surveillance of the patient's neurological function during tumor resection and the postoperative phase, minimizing complications. In addition, our data show that the use of dexmedetomidine results in a shorter time to arousal.

Hospital costs associated with inpatient versus outpatient awake craniotomy for resection of brain tumors

BackgroundWith increasing fiscal restraints on health care systems, procedural cost-effectiveness has become an important metric for evaluating surgical procedures. While outpatient craniotomy has been shown to be safe and effective, the economic implications of this procedure has yet to be examined. Here, we present the first cost analysis comparing inpatient versus outpatient awake craniotomy for tumor resection/biopsy. MethodsWe conducted a retrospective chart review on consecutive patients undergoing awake craniotomy for tumor resection/biopsy at a publicly funded tertiary care center from Sept 2014 to Aug 2015. Patient demographics, comorbidities and surgical factors were recorded. Direct and indirect costs for each patient visit were calculated based on institutional records. ResultsA total of 50 consecutive patients undergoing awake craniotomy for tumor resection were included in this study (29 outpatients, 21 inpatients). Rates of complications and 30-day readmission were similar between groups. The total costs associated with inpatient surgery were nearly double that of outpatient surgery ($10649 versus $5242, P < 0.001). In-patient surgery resulted in a nearly 6-fold increase in unit/bed costs compared to out-patient surgery ($4142 versus $758, P < 0.001). There were no differences in the costs incurred from the operating room, laboratory, or anesthesia departments. ConclusionsCosts associated with outpatient craniotomy are nearly half compared to inpatient craniotomy and this is largely driven by reductions in bed resource utilization and allied health services. Outpatient neurosurgery for tumor resection is therefore a safe and feasible option for appropriately selected patients and confers an overall cost reduction.

Resection of Gliomas with and without Neuropsychological Support during Awake Craniotomy-Effects on Surgery and Clinical Outcome.

During awake craniotomy for tumor resection, a neuropsychologist (NP) is regarded as a highly valuable partner for neurosurgeons. However, some centers do not routinely involve an NP, and data to support the high influence of the NP on the perioperative course of patients are mostly lacking. The aim of this study was to investigate whether there is a difference in clinical outcomes between patients who underwent awake craniotomy with and without the attendance of an NP. Our analysis included 61 patients, all operated on for resection of a presumably language-eloquent glioma during an awake procedure. Of these 61 cases, 47 surgeries were done with neuropsychological support (NP group), whereas 14 surgeries were performed without an NP (non-NP group) due to a language barrier between the NP and the patient. For these patients, neuropsychological assessment was provided by a bilingual resident. Both groups were highly comparable regarding age, gender, preoperative language function, and tumor grades (glioma WHO grades 1-4). Gross total resection (GTR) was achieved more frequently in the NP group (NP vs. non-NP: 61.7 vs. 28.6%, P = 0.04), which also had shorter durations of surgery (NP vs. non-NP: 240.7 ± 45.7 vs. 286.6 ± 54.8 min, P < 0.01). Furthermore, the rate of unexpected tumor residuals (estimation of the intraoperative extent of resection vs. postoperative imaging) was lower in the NP group (NP vs. non-NP: 19.1 vs. 42.9%, P = 0.09), but no difference was observed in terms of permanent surgery-related language deterioration (NP vs. non-NP: 6.4 vs. 14.3%, P = 0.48). We need professional neuropsychological evaluation during awake craniotomies for removal of presumably language-eloquent gliomas. Although these procedures are routinely carried out with an NP, this is one of the first studies to provide data supporting the NP's crucial role. Despite the small group size, our study shows statistically significant results, with higher rates of GTR and shorter durations of surgery among patients of the NP group. Moreover, our data emphasize the common problem of language barriers between the surgical and neuropsychological team and patients requiring awake tumor resection.

Patients' Perioperative Experience of Awake Deep-Brain Stimulation for Parkinson Disease.

Awake craniotomy for tumor resection and epilepsy surgery is a well-tolerated procedure. Qualitative data on patients' experience of awake deep-brain stimulation (DBS) are, however, lacking. We collected qualitative data on patients' experience of awake DBS with a view to identifying areas for improvement. Forty-one patients undergoing DBS for Parkinson disease between 2009 and 2015 were surveyed with a structured questionnaire designed to receive patient feedback regarding perioperative management of the awake stage of the procedure. More than 90% of patients felt well-informed. Most remembered the procedure, and almost all were happy that they did. One half of the patients experienced pain, often significant, during the procedure. This mainly occurred during burr-hole drilling and stereotactic frame placement. Although awake DBS is well-tolerated, pain and off-period symptoms are an issue for a significant number of patients. Efforts should be made to minimize these unpleasant aspects of awake DBS.

Awake Craniotomy for Tumor Resection: Further Optimizing Therapy of Brain Tumors.

In recent years more and more data have emerged linking the most radical resection to prolonged survival in patients harboring brain tumors. Since total tumor resection could increase postoperative morbidity, many methods have been suggested to reduce the risk of postoperative neurological deficits: awake craniotomy with the possibility of continuous patient-surgeon communication is one of the possibilities of finding out how radical a tumor resection can possibly be without causing permanent harm to the patient.In 1994 we started to perform awake craniotomy for glioma resection. In 2005 the use of intraoperative high-field magnetic resonance imaging (MRI) was included in the standard tumor therapy protocol. Here we review our experience in performing awake surgery for gliomas, gained in 219 patients.Patient selection by the operating surgeon and a neuropsychologist is of primary importance: the patient should feel as if they are part of the surgical team fighting against the tumor. The patient will undergo extensive neuropsychological testing, functional MRI, and fiber tractography in order to define the relationship between the tumor and the functionally relevant brain areas. Attention needs to be given at which particular time during surgery the intraoperative MRI is performed. Results from part of our series (without and with ioMRI scan) are presented.

Anesthesia in Awake Craniotomy: Advantages of Dexmedetomidine Infusion over Conventional Methods

Background/objectives: Dexmedetomidine, an α 2 agonist used as infusion with scalp block, is a good adjuvant with analgesic, anxiolytic, and sedative effect with minimal effects on hemodynamic changes and respiration depression. In this study, we report the efficacy of dexmeditomidine for awake craniotomy. Materials and methods: Three American Society of Anesthesiologists grade 2 patients were posted for tumor resection under awake craniotomy. Scalp block was given with local anesthetic and dexmedetomidine bolus dose of 1 μg/kg/hr followed by 0.2 to 0.4 μg/kg/hr. The patient's speech was monitored by oral questionnaire, motor strength by hand squeezing, and sedation by modified Ramsay Hunt Score. Results: Bolus dose of 1 μg/kg over 20 minutes infusion of 0.2 to 0.4 μg/kg/hr is a good adjuvant with scalp block with minimal hemodynamic changes. Conclusion: Dexmedetomidine is a useful adjuvant during awake craniotomy for tumor resection. It has minimal effect on hemodynamics and respiratory system. It can be used in procedures where cooperation of the patient is required intraoperatively.

INTRA-OPERATIVE MAPPING OF NEURAL NETWORKS DURING AWAKE CRANIOTOMY FOR RESECTION OF BRAIN TUMORS: WORK IN PROGRESS

BACKGROUND: Direct cortical stimulation (DCS) is considered the gold-standard for identification of functional brain regions during awake craniotomy for tumor resection. This technique allows maximal resection while preserving neurological function and quality of life. To date, no intra-operative methodology for mapping neural networks, which are crucial for adequate neurological functions, has been described. We describe the feasibility of a novel intra-operative technique, aiming to map critical language sub-networks using simultaneous, multi-site cortical stimulations. METHODS: 15 eligible patients who underwent awake craniotomy for removal of tumors involving language areas participated in this study. Following standard DCS using a bipolar Ojemann stimulator, a strip electrode was placed on “silent” cortex (where DCS has not elicited any language dysfunction). Functional testing was continued while applying simultaneous two to three-site bipolar stimulation via two pairs of adjacent contacts and Ojemann stimulator. Dysfunction was documented when occurred consistently during stimulation. RESULTS: 12 of the 15 patients (80%) experienced language dysfunction following standard single-site stimulation. Two-site simultaneous stimulations (neither causing dysfunction by itself) were associated with additive language dysfunction in 10 of the 15 patients. Three-site stimulations caused additive language dysfunction in 8 patients, as compared to the single- and two- site stimulations. Language dysfunctions caused by multifocal stimulation varied among patients and tumor locations and included primary production and comprehension dysfunctions (i.e. speech arrest and word-deafness, respectively); as well as secondary language dysfunctions such as phonological and semantic paraphasias. Importantly, using multifocal stimulations we identified eloquent regions in patients who did not experience any dysfunction using the standard DCS (two patients). Functional regions identified were spared during surgery. In none of the patients a new neurological deficit was observed following surgery, and in six patients who experienced dysfunction caused by multifocal stimulation, post-operative language function has improved. CONCLUSIONS: In this preliminary study we show that multi-site intra-operative stimulations enables identification of additional functional nodes and sub-networks which are more refined and cannot be mapped with standard single site stimulations. Using such technique may allow for preservation of neural networks and further enhance functional preservation in patients who undergo surgery for brain tumors. SECONDARY CATEGORY: n/a.

Does midline shift predict postoperative nausea in brain tumor patients undergoing awake craniotomy? A retrospective analysis

Background:The presence of midline shift on neuroradiologic studies in brain tumor patients represents mass effect from the tumor and surrounding edema. We hypothesized that baseline cerebral edema as measured by midline shift would increase postoperative nausea (PON). We studied the incidence of PON in brain tumor patients, with and without midline shift on preoperative magnetic resonance (MRI) or computed tomographic (CT) imaging, undergoing awake craniotomy.Methods:After IRB approval, we retrospectively extracted data from perioperative records between January 2005 and December 2010. Post-craniotomy nausea and pain scores were collected. Intraoperative anti-emetic, anesthetic, and analgesic regimens were assessed. Both the rescue anti-emetic and cumulative postoperative analgesic requirements were collected up to 12 hours postoperatively. The amount of midline shift on preoperative neuroimaging was gathered from radiology reports. Univariate comparisons between groups (no midline shift vs. midline shift) were made with t-tests for continuous variables, and chi-square tests for categorical variables. A multivariable analysis was performed to identify predictors of postoperative nausea. Limitations of this study include the retrospective design and the inability to gather accurate data regarding vomiting from the medical record.Results:Data from 386 patients were available for analysis. Patients were divided into two groups: no midline shift (n = 283) and midline shift (n = 103). The mean midline shift distance was 5.96 mm (95% CI [5.32, 6.59]). There was no difference in the incidence of nausea or pain scores between the two groups. More malignant brain tumor patients were in the midline shift group, as determined by the postoperative histopathological diagnosis (P < 0.05). Patients in the midline shift group also had longer anesthesia and surgical times (P < 0.05).Conclusion:In patients undergoing a standardized anesthetic for awake craniotomy for tumor resection, the presence of preoperative midline shift did not correlate with postoperative nausea.

Development of a Safe and Pragmatic Awake Craniotomy Program at Maine Medical Center

Awake craniotomy offers an excellent means of performing intraoperative mapping and optimizing surgical resection of brain tumors. Awake craniotomy relies on a strong collaboration between anesthesiologists, neurosurgeons, and operating room staff. The authors recently introduced awake craniotomy for tumor resection at the Maine Medical Center and propose that it can be performed safely, effectively, and efficiently in a high-volume community hospital. We describe a practical approach to performing awake craniotomy involving streamlined anesthetic protocols and simplified intraoperative testing parameters in a carefully selected group of patients. Our first 25 patients are retrospectively reviewed with particular attention to the anesthetic protocol, the extent of resection, the operative time, post-operative complications, the length of hospitalization, and their functional status at follow-up. The authors established an anesthetic protocol based primarily on midazolam, fentanyl, propofol, and local anesthetic. The authors note that all but one patient was able to tolerate the awake procedure. Gross total resection was achieved in nearly 80% of patients with a glial tumor. Operative time was short, averaging 159 minutes of entire anesthesia care. Length of stay averaged 3.7 days. Persistent new post-operative deficits were noted in 2 of 25 patients. There was no substantial difference in total hospital charges for patients undergoing awake craniotomy when compared to a matched historical control. With attention focused on patient selection and a streamlined anesthetic protocol, the authors were able to successfully implement an awake craniotomy protocol in a community setting with satisfying results, including low operative morbidity, short operative times, low anesthetic complications, and excellent patient tolerance.

Diagnosis and conservative management of an arteriovenous fistula of the scalp following awake craniotomy for tumor resection

Diagnosis and conservative management of an arteriovenous fistula of the scalp following awake craniotomy for tumor resection

Use of the laryngeal mask airway during awake craniotomy for tumor resection

There is an increasing trend toward performing craniotomy for primary brain tumor excision with local anesthesia. We report the use of the laryngeal mask airway as a part of an anesthetic technique designed for patients requiring awake cortical mapping during brain tumor excision.