Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Lateral Supraorbital Approach with Expanded Indications.

Objectives The lateral supraorbital (LSO) approach is a less-invasive alternative to the pterional craniotomy that provides rapid transsylvian access. Establishing familiarity with the LSO technique and its features as compared with other anterolateral approaches is an important component of advanced skull base training. We present a step-by-step demonstration of the LSO approach using cadaveric dissection in a manner that is digestible for trainees at various levels. Design This is anatomic step-by-step dissection and representative case series. Setting This study was carried out in the cadaveric dissection laboratory. Participants A formalin-fixed, latex-injected cadaveric head specimen was dissected under microscopic magnification by a neurosurgery resident under faculty supervision. Following dissection, representative case applications were reviewed. Main Outcome Measures Dissection and case illustration were the main outcome measures. Results A single-layer myocutaneous flap is developed, and a single-burr-hole technique is used, followed by extensive drilling of the sphenoid wing. The dura is opened in a C-shaped fashion centered on the Sylvian fissure, exposing the inferior frontal and superior temporal lobes. Labeled photographs of dissections with pertinent anatomical structures are presented. Three case examples illustrating the versatility of the LSO approach, including the resection of a large pituitary adenoma, an inferior frontal melanoma metastasis presenting to the Sylvian surface, and a frontoinsular low-grade glioma, are reviewed. Conclusion As compared with the pterional craniotomy, the LSO approach involves a shorter incision, smaller craniotomy, and faster exposure; it can be conveniently tailored to various indications. Understanding the step-by-step dissection and indications of the LSO approach is of paramount importance to neurosurgery trainees.

Two Cases of Remimazolam Anesthesia Managed With Pharmacokinetic Simulations in an Awake Craniotomy of Patients With Obesity.

Anesthetic management for awake craniotomy (AC) often poses problems in patients with obesity including respiratory management. The Japan Awake Craniotomy Guidelines state that the indication for surgery should be carefully considered, especially in patients with obesity (body mass index (BMI) > 30). Patients with obesity often have comorbidities such as dyslipidemia, hypertension, and type 2 diabetes, and this is a risk factor for perioperative morbidity and mortality. Remimazolam, a new intravenous anesthetic, has been reported to be useful in anesthesia management during AC, but its use in obese patients has not been reported. Herein, we report two cases case series in which remimazolam was used in patients with obesity and safely managed under anesthesia with the pharmacokinetic simulations.

A review of acute symptomatic seizures during awake craniotomy for tumour resection.

PURPOSE: Awake craniotomy (AC) is a procedure often performed concomitantly with direct electrical cortical stimulation (DES) and electrocorticography (ECoG) during functional brain mapping. Patients undergoing AC are at risk of acute symptomatic seizures, including intraoperative (IS) and early postoperative seizures (EPS) which can lead to higher risk of morbidity. Predicting those who are at risk of IS and EPS could alert clinicians and provide the ability to closely monitor and consider management changes in the acute setting to prevent seizures. MATERIALS AND METHODS: This is a narrative review of previous studies on IS and EPS during awake craniotomy, including a summary of studies from our center using a novel circular grid electrode. RESULTS AND CONCLUSIONS: There are a number of clinical features with variable association with a higher risk of EPS and IS. Surgeries involving the anterior and central head regions are a risk factor for IS. EPS is more likely to occur in patients with perioperative intracranial hemorrhage. Improving grid/electrode technology for ECoG can allow for better sensitivity of detecting epileptiform activity which can help to diagnose and predict perioperative seizures.

Awake Craniotomy in Epilepsy Surgery: A Case Series and Proposal for Three Different Scenarios.

OBJECTIVE: Awake craniotomy (AWC) allows intraoperative evaluation of functions involving the cortical surface and subcortical fibers. In epilepsy surgery, indications for and the role of AWC have not been established because evaluation with intracranial electrodes is considered the gold standard. We report herein our case series of patients who underwent AWC in epilepsy surgery and propose the scenarios for and roles of AWC. METHODS: Patients who underwent AWC in epilepsy surgery at our institutions between 2014 and 2023 were included. Information about age, sex, etiology, location of epileptogenicity, seizure type, use of intracranial electrode placement, surgical complications, neurological deficits, additional surgery, and seizure outcomes was reviewed. Following a diagnostic and treatment flow for epilepsy surgery, we clarified three different scenarios and roles for AWC. RESULTS: Ten patients underwent AWC. Three patients underwent AWC after non-invasive evaluations. Two patients underwent AWC after intracranial evaluation with stereotactic electroencephalography (SEEG). Five patients underwent AWC after intracranial evaluation with subdural grid electrodes (SDG). Among these, two patients were initially evaluated with SEEG and with SDG thereafter. One patient reported slight numbness in the hand, and one patient showed slight cognitive decline. Seizure outcomes according to the Engel outcome scale were class 1A in three patients, IIA in two patients, IIIA in four patients, and IVA in one patient. CONCLUSIONS: AWC can be used for purposes of epilepsy surgery in different situations, either immediately after non-invasive studies or as an additional invasive step after invasive monitoring with either SEEG or SDG. The application of AWC should be individualized according to each patient's specific characteristics.

Intraoperative glioblastoma surgery-current challenges and clinical trials: An update.

Surgical excision is an important part of the multimodal therapy strategy for patients with glioblastoma, a very aggressive and invasive brain tumor. While major advances in surgical methods and technology have been accomplished, numerous hurdles remain in the field of glioblastoma surgery. The purpose of this literature review is to offer a thorough overview of the current challenges in glioblastoma surgery. We reviewed the difficulties associated with tumor identification and visualization, resection extent, neurological function preservation, tumor margin evaluation, and inclusion of sophisticated imaging and navigation technology. Understanding and resolving these challenges is critical in order to improve surgical results and, ultimately, patient survival.

Dexamethasone versus 5-HT3 receptor antagonists in preventing nausea during awake craniotomy: a propensity score matching study.

BACKGROUND: Nausea and vomiting during awake craniotomy (AC) can increase cerebral pressure and cause asphyxia and aspiration. 5-HT3 receptor antagonists, such as granisetron, are often administered before awakening to prevent nausea during AC. Recently, dexamethasone was reported to prevent nausea and vomiting during AC; however, the efficacy of both drugs in preventing nausea has not yet been investigated. METHODS: We examined the frequency of nausea and vomiting in AC patients (n = 170) treated at our hospital until the end of September 2019. We divided patients as those who received dexamethasone (n = 71) and or granisetron (n = 99) before awakening and examined the frequency of nausea and vomiting after propensity score (PS) matching. RESULT: Eighty-two patients were selected after PS matching. The incidence of nausea was significantly lower in the dexamethasone group than in the granisetron group (9.8% vs 41.5%, p = 0.002). In the logistic regression analysis after matching, the incidence of nausea significantly reduced with dexamethasone treatment (odds ratio: 0.12, 95% confidence interval: 0.029-0.499, p = 0.03). CONCLUSION: In conclusion, dexamethasone was more effective than granisetron in preventing nausea during AC.

Experiences in Awake Craniotomy from Borneo: A Case Series from Sarawak General Hospital.

Background: The indications for awake craniotomy now spans from resection of tumours at eloquent areas of the brain, deep brain stimulation and treatment of aneurysms to name a few. In the region of East Malaysia where patients have various ethnic backgrounds and native languages, planning and execution of these procedures can be somewhat challenging. Methods: This is a retrospective analysis of 11 awake surgeries conducted by the Department of Neurosurgery in Sarawak. The indications for awake craniotomy surgery in our sample population were intra-axial lesions in eloquent regions involving important cortical areas and subcortical tracts which were at risk of damage during tumour excision. Patients were assessed for intra-operative and post-operative neurological deficits. Results: Eleven patients aged 20 years old-70 years old were included in this series. All patients were diagnosed with lesions in eloquent areas of the brain requiring surgical excision. Patients were of various ethnic backgrounds. The spoken language of these patients also varied based on their ethnicity. The histopathological diagnosis of nine patients were consistent with gliomas with three being of high grade. Three patients (27%) developed intra-operative deficits that were not present pre-operatively. Conclusion: This case series serve to demonstrate the feasibility of awake craniotomies even in centres without vast experiences in awake surgeries and ideal adjuncts which in comparison may be readily available in different centres. Although careful patient selection has been emphasised, it is a difficult feat in a region consisting of at least 30 different ethnic groups with distinct languages and cultures.

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

BACKGROUND: 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. METHODS: 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". RESULTS: 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. CONCLUSIONS: 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.

"Apathetic look" is a valuable indicator of intraoperative supplementary motor area syndrome during awake craniotomy.

Resection of a glioma from the dorsomedial frontal lobe, including the supplementary motor area (SMA), can result in postoperative SMA syndrome. SMA syndrome may occur during awake craniotomies. However, it is often difficult to intraoperatively distinguish between motor dysfunction due to pyramidal tract damage from that due to SMA syndrome. Patients with suspected intraoperative SMA syndrome are indifferent to their surroundings, have stiff facial muscles, and maintain a fixed gaze. We defined this condition as "apathetic look." The present study aimed to investigate whether intraoperative "apathetic look" is useful for identifying intraoperative SMA syndrome in patients with glioma close to motor-related areas, including the SMA, during awake craniotomy. This study included 33 consecutive patients with glioma included in the SMA. We excluded patients whose tumors extended to motor-related areas. We also assessed whether intraoperative SMA syndrome occurred in each patient. We evaluated the correlation between the occurrence of intraoperative SMA syndrome and various clinical factors, including intraoperative "apathetic look." Of the 33 patients, 12 had intraoperative SMA syndrome. Intraoperative "apathetic look" showed strong correlation with intraoperative SMA syndrome (p < 0.0001). Additionally, higher extent of resection (EOR) and resection of the corpus callosum showed a significantly higher incidence of intraoperative "apathetic look." All 12 patients with intraoperative SMA syndrome showed intraoperative "apathetic look" and recovered from SMA syndrome with high EOR. In conclusion, intraoperative "apathetic look" shows strong correlation with intraoperative SMA syndrome. Therefore, "apathetic look" may be a valuable indicator of intraoperative SMA syndrome during awake craniotomy.

Onco-functional outcome after resection for eloquent glioblastoma (OFO): A propensity-score matched analysis of an international, multicentre, cohort study.

BACKGROUND: The combined impact of complete resection (oncological goal) and no functional loss (functional goal) in glioblastoma subgroups is currently unknown. This study aimed to develop a novel onco-functional outcome (OFO) to merge these two goals into one outcome, resulting in four classes: complete without deficits (OFO1), incomplete without deficits (OFO2), complete with deficits (OFO3), or incomplete with deficits (OFO4). METHODS: Between 2010-2020, 858 patients with tumor resection for eloquent glioblastoma were included. We analyzed the impact of OFO class on postoperative surgical outcomes using Cox proportional-hazards models with hazard ratios (HR) or logistic regression with odds ratios (OR), followed by specific subgroup analyses. We developed a risk model to predict OFO class preoperatively using logistic regression. RESULTS: The OFO classification stratified the four OFO classes for overall survival (OS:19.0 versus 14.0 versus 12.0 versus 9.0 months), progression-free survival (PFS), and adjuvant therapy. OFO1 was associated with improved OS [HR= 0.67, (0.55-0.81); p < 0.001], and PFS [HR = 0.68, (0.57-0.81); p < 0.001] in the overall cohort and all clinical and molecular subgroups, except for MGMT-unmethylated tumors; and higher rate of adjuvant therapy [OR= 2.81, (1.71-4.84);p < 0.001]. In patients≥ 70 years, only OFO1 improved their survival outcomes. Safe surgery was especially important in patients with a preoperative KPS ≤ 80 to qualify for adjuvant treatment. Awake craniotomy more often led to OFO1 compared to asleep resection [OR = 1.93, (1.19-3.14); p = 0.008]. CONCLUSIONS: OFO1 was associated with improved OS, PFS, and receipt of adjuvant therapy in all glioblastoma patients with IDH-wildtype and MGMT-methylated tumors. Awake craniotomy was associated with achieving this optimal OFO status. Preventing deficits was more important than complete surgery.

The role of postoperative blood pressure management in early postoperative hemorrhage in awake craniotomy glioma patients.

Postoperative hemorrhage can severely affect the patients' neurological outcome after awake craniotomy. Higher postoperative blood pressure can increase the risk of postoperative hemorrhage. The aim of this study was to investigate the role of postoperative blood pressure and other common radiological and epidemiological features with the incidence of postoperative hemorrhage. In this retrospective analysis, we included patients who underwent awake surgery at our institution. We assessed the blood pressure both intra- and postoperatively as well as the heart rate for the first 12 h. We compared a cohort with postoperative hemorrhage, who required further treatment (surgical revision or intravenous antihypertensive therapy), with a cohort with no postoperative hemorrhage. We included 48 patients with a median age of 39 years. 9 patients (19%) required further treatment due to postoperative hemorrhage, which was surgery in 2 cases and intensive blood pressure measurements in 7 cases. However, with early treatment, no significant difference in Performance scores at follow-up could be found. Patients with postoperative hemorrhage showed significantly higher postoperative systolic blood pressure during the hours 3-12 (p < 0.05) as well as intraoperatively throughout the procedure (p < 0.05). In ROC and Youden Test, a strong impact of systolic blood pressure over 140mmHg during the early postoperative course could be shown. Postoperative hemorrhage is a rare but possible complication in awake surgery glioma patients. To avoid postoperative hemorrhage, treating physicians should aim strictly on systolic blood pressure of under 140mmHg for the postoperative course.

Optimizing Glioma Resection Outcomes: A Systematic Review of Intraoperative Magnetic Resonance Imaging Guidance in Neurosurgery.

This systematic review evaluates the efficacy of intraoperative magnetic resonance imaging (iMRI) in enhancing glioma resection outcomes within neurosurgical procedures. Given the complexity and variability of gliomas, achieving precise and safe resections is challenging, necessitating the use of advanced imaging techniques like iMRI. This technology provides real-time, high-resolution insights during surgery, allowing for adaptations based on surgical dynamics and brain shifts. Our comprehensive search across multiple databases selected five significant studies that collectively demonstrate the beneficial impact of iMRI. These studies highlight its role in significantly improving the extent of tumor resection and suggest potential enhancements in both immediate and long-term patient outcomes. The findings indicate that iMRI facilitates more aggressive yet safe resections, particularly in high-risk glioma cases. However, the implementation of iMRI in clinical practice requires careful consideration of training, resource allocation, and the potential variability in outcomes due to study design heterogeneity. Future research should focus on randomized controlled trials to better understand the cost-effectiveness and long-term benefits of iMRI, promoting its wider adoption in neurosurgical settings.

Filling the gap: brief neuropsychological assessment protocol for glioma patients undergoing awake surgeries.

Introduction: The literature lacks a concise neurocognitive test for assessing primary cognitive domains in neuro-oncological patients. This study aims to describe and assess the feasibility of the Ohy-Maldaun Fast Track Cognitive Test (OMFTCT), used to pre- and post-operatively evaluate patients undergoing brain tumor surgery in language eloquent areas. The cognitive diagnosis was used to safely guide intraoperative language assessment. Methods: This is a prospective longitudinal observational clinical study conducted on a cohort of 50 glioma patients eligible for awake craniotomies. The proposed protocol assesses multiple cognitive domains, including language, short-term verbal and visual memories, working memory, praxis, executive functions, and calculation ability. The protocol comprises 10 different subtests, with a maximum score of 50 points, and was applied at three time points: preoperative, immediately postoperative period, and 30 days after surgery. Results: Among the initial 50 patients enrolled, 36 underwent assessment at all three designated time points. The mean age of the patients was 45.3 years, and they presented an average of 15 years of education. The predominant tumor types included Glioblastoma, IDH-wt (44.1%), and diffuse astrocytoma, IDH-mutant (41.2%). The tumors were located in the left temporal lobe (27.8%), followed by the left frontal lobe (25%). The full test had an average application time of 23 min. Conclusion: OMFTCT provided pre- and postoperative assessments of different cognitive domains, enabling more accurate planning of intraoperative language testing. Additionally, recognition of post-operative cognitive impairments played a crucial role in optimizing patient care.

Successful Second Awake Craniotomy Reoperation With Dexmedetomidine After an Initial Abandonment Case Due to Restlessness.

Awake craniotomy (AC) is sometimes aborted due to poor arousal and restlessness. Dexmedetomidine (DEX), an α2-adrenoreceptor agonist, has sedative, analgesic, and anesthetic-sparing effects, with a low risk of respiratory depression, making it effective for intraoperative pain and agitation during the awake phase. We report a case in which AC was successfully performed in combination with low-dose continuous administration of DEX during reoperation in a patient who experienced poor arousal and restlessness during their first surgery, leading to the abandonment of AC. The patient is a 48-year-old male who is scheduled for AC reoperation. Two years ago, the first AC was scheduled and performed under anesthesia with propofol and remifentanil. However, AC was abandoned due to poor intraoperative arousal and restlessness. At reoperation, general anesthesia was induced with propofol and continuous administration of remifentanil (0.1 µg/kg/min); following anesthesia induction (continuous infusion of propofol, remifentanil, and a bolus infusion of fentanyl), DEX was also administered (0.2 µg/kg/hour). We performed a scalp nerve block. Before the awake phase, the propofol dose was decreased as was DEX to 0.1 µg/kg/hour, and propofol and remifentanil were discontinued. The patient gradually awoke without any agitation and restlessness 24 min after stopping propofol and remifentanil and could perform language tasks without any complications. In this case, AC was successfully performed in combination with continuous low-dose administration of DEX at the time of reoperation in a patient who experienced poor arousal and restlessness during their first operation and had to discontinue AC.

The Use of Remimazolam During Awake Craniotomy for Seizure Foci Resection in Adolescents: A Case Series.

Remimazolam is a novel benzodiazepine with sedative, anxiolytic, and amnestic properties similar to midazolam. Metabolism by tissue esterases results in a short clinical half-life of 5 - 10 min and a limited context sensitive half-life. We present initial retrospective clinical experience with the use of remimazolam as an intraoperative adjunct to sedation during awake craniotomy in a cohort of three adolescent patients. A remimazolam infusion was added to a combination of dexmedetomidine and remifentanil to deepen the level of sedation during surgical incision, craniotomy, duraplasty, and surgical dissection for exposure of the seizure foci. The remimazolam infusion was discontinued 30 min prior to the planned awake assessments and electrophysiology testing. The patients emerged calmly and were able to follow commands for intraoperative testing. Our anecdotal experience supports the efficacy of remimazolam for awake craniotomy and tumor resection using a standard asleep-awake-asleep technique. We noted adequate sedation, maintenance of spontaneous respiration, rapid awakening, and no limitations to intraoperative neuromonitoring or awake assessment in our three patients.

Awake neurosurgery: Advancements in microvascular decompression for trigeminal neuralgia.

Background: The treatment landscape for trigeminal neuralgia (TN) involves various surgical interventions, among which microvascular decompression (MVD) stands out as highly effective. While MVD offers significant benefits, its success relies on precise surgical techniques and patient selection. In addition, the emergence of awake surgery techniques presents new opportunities to improve outcomes and minimize complications associated with MVD for TN. Methods: A thorough review of the literature was conducted to explore the effectiveness and challenges of MVD for TN, as well as the impact of awake surgery on its outcomes. PubMed and Medline databases were searched from inception to March 2024 using specific keywords "Awake Neurosurgery," "Microvascular Decompression," AND "Trigeminal Neuralgia." Studies reporting original research on human subjects or preclinical investigations were included in the study. Results: This review highlighted that MVD emerges as a highly effective treatment for TN, offering long-term pain relief with relatively low rates of recurrence and complications. Awake surgery techniques, including awake craniotomy, have revolutionized the approach to MVD, providing benefits such as reduced postoperative monitoring, shorter hospital stays, and improved neurological outcomes. Furthermore, awake MVD procedures offer opportunities for precise mapping and preservation of critical brain functions, enhancing surgical precision and patient outcomes. Conclusion: The integration of awake surgery techniques, particularly awake MVD, represents a significant advancement in the treatment of TN. Future research should focus on refining awake surgery techniques and exploring new approaches to optimize outcomes in MVD for TN.

Awake craniotomy in pediatric low-grade glioma: barriers and future directions.

INTRODUCTION: The goal of surgical management in pediatric low-grade gliomas (pLGGs) is gross total resection (GTR), as it is considered curative with favorable long-term outcomes. Achieving GTR can be challenging in the setting of eloquent-region gliomas, in which resection may increase risk of neurological deficits. Awake craniotomy (AC) with intraoperative neurofunctional mapping (IONM) offers a promising approach to achieve maximal resection while preserving neurological function. However, its adoption in pediatric cases has been hindered, and barriers to its adoption have not previously been elucidated. FINDINGS: This review includes two complementary investigations. First, a survey study was conducted querying pediatric neurosurgeons on their perceived barriers to the procedure in children with pLGG. Next, these critical barriers were analyzed in the context of existing literature. These barriers included the lack of standardized IONM techniques for children, inadequate surgical and anesthesia experience, concerns regarding increased complication risks, doubts about children's ability to tolerate the procedure, and perceived non-indications due to alternative monitoring tools. CONCLUSION: Efforts to overcome these barriers include standardizing IONM protocols, refining anesthesia management, enhancing patient preparation strategies, and challenging entrenched beliefs about pediatric AC. Collaborative interdisciplinary efforts and further studies are needed to establish safety guidelines and broaden the application of AC, ultimately improving outcomes for children with pLGG.

Upward Herniation in Awake Craniotomy: A Case Report.

Awake craniotomy has been gaining popularity for the last decade. It allowed maximum tumor resection while avoiding neurological morbidity. However, this technique presents several challenges to both the neurosurgeon and anesthesiologist. In this case, we present a 33-year-old male who was diagnosed with low-grade glioma in the left parieto-occipital, which required surgical resection. Anatomically, the tumor was located in the language area. Hence, it was decided to perform an awake craniotomy excision of the tumor to allow intraoperative cortical mapping to preserve language functions. Intraoperative, a subdural hematoma was noted, and severe pain occurred. Eventually, this leads to an upward herniation of the brain parenchyma. The crisis was addressed promptly with maneuvers to decrease intracranial pressure. Awake craniotomy was abandoned, and the procedure was converted to general anesthesia without the benefit of intraoperative cortical mapping. It is important to note that complications may arise during the procedure, leading to significant harm and debilitation for the patient. Prompt crisis management is necessary to address these potential issues and ensure the highest level of care is provided.

Awake Craniotomy for a Frontal Astrocytoma: A Case Report.

Awake craniotomy is a surgical procedure that has been gaining significance over the past decades. Neuronavigation is an intraoperative technology that locates tumors and monitors the brain cortex during awake craniotomy. The presence of cerebral low-grade gliomas in the frontal lobe creates a risk of affecting vital centers of the brain cortex during surgery. We present a clinical case of a 42-year-old male patient who entered the neurosurgery clinic with a clinical manifestation of headache for two months. MRI showed evidence of the recurrence of a left frontal glioma. Differential diagnoses of frontal gliomas include metastases, abscesses, and cysts. The pathophysiologic background of the disease is the mutation of neuroglial cells, which leads to an abnormal and uncontrollable proliferation. Under sleep-awake anesthesia, operative treatment was performed through left frontal awake craniotomy under neuronavigation. As a result, a total excision was achieved. Motor functions of the right limbs and speech have been preserved. The patient was mobilized on the day after the intervention. Surgery-related complications were not observed. The patient had relief from the symptoms and was discharged on the fifth day. Awake craniotomy combined with neuronavigation was the most efficient and the least harmful method for the excision of the tumor. For low-grade gliomas localized in the frontal area of the encephalon, awake craniotomy is the only secure option for surgery.

Awake craniotomy in patients with arteriovenous malformation: A systematic review and meta­analysis.

The present systematic review aimed to identify all the available literature on awake craniotomy (AC) in patients with arteriovenous malformation (AVM) in order to evaluate its safety, risks, benefits and effectiveness. All available literature on AC in patients with AVM was collected and evaluated in an aim to provide a better understanding of its safety, associated risks and benefits. A systematic search for studies employing AC in patients with AVM was conducted using the PubMed, Scopus and ScienceDirect databases without restrictions on the year of publication, language, or study design, from inception up to May 30, 2021. A total of 11 studies published between 2004 and 2021 with 106 patients who underwent ACs were considered eligible. The rate of complete resection was 93% [95% confidence interval (CI), 82 to 100%; I2 0%]. The intraoperative complication rate was 21% (95% CI, 1 to 41%; I2 55%) and the post-operative complication rate was 33% (95% CI, 19 to 48%; I2 40%). During follow-up, the complication rate was 6% (95% CI, 1 to 10%; I2 30%). The post-operative complication rate was higher in the Spetzler-Martin grade (SMG) III-V group (31%; 95% CI, 21 to 42%; I2 46%) than in the SMG I-II group (12%; 95% CI, 2 to 22%; I2 0%). Similarly, the follow-up complication rate was higher in the SMG III-V group (9%; 95% CI, 2 to 16%; I2 34%) than in the SMG I-II group (0%; 95% CI, 0 to 4%; I2 0%). On the whole, the present study provides preliminary evidence to indicate that AC is a possible and useful option for the resection of AVM in selected patients. Well-designed future studies with long-term follow-up are required however, to investigate various aspects of safety and provide solid data for AC in patients with AVM.