Failed awake craniotomy: a retrospective analysis in 424 patients undergoing craniotomy for brain tumor

Difficulty in identification of the frontal language area in patients with dominant frontal gliomas that involve the pars triangularis

OBJECTIVE Identification of language areas using functional brain mapping is sometimes impossible using current methods but essential to preserve language function in patients with gliomas located within or near the frontal language area (FLA). However, the factors that influence the failure to detect language areas have not been elucidated. The present study evaluated the difficulty in identifying the FLA in dominant-side frontal gliomas that involve the pars triangularis (PT) to determine the factors that influenced failed positive language mapping. METHODS Awake craniotomy was performed on 301 patients from April 2000 to October 2013 at Tokyo Women's Medical University. Recurrent cases were excluded, and patients were also excluded if motor mapping indicated their glioma was in or around the motor area on the dominant or nondominant side. Eighty-two consecutive cases of primary frontal glioma on the dominant side were analyzed for the present study. MRI was used for all patients to evaluate whether tumors involved the PT and to perform language functional mapping with a bipolar electrical stimulator. Eighteen of 82 patients (mean age 39 ± 13 years) had tumors that showed involvement of the PT, and the detailed characteristics of these 18 patients were examined. RESULTS The FLA could not be identified with intraoperative brain mapping in 14 (17%) of 82 patients; 11 (79%) of these 14 patients had a tumor involving the PT. The negative response rate in language mapping was only 5% in patients without involvement of the PT, whereas this rate was 61% in patients with involvement of the PT. Univariate analyses showed no significant correlation between identification of the FLA and sex, age, histology, or WHO grade. However, failure to identify the FLA was significantly correlated with involvement of the PT (p < 0.0001). Similarly, multivariate analyses with the logistic regression model showed that only involvement of the PT was significantly correlated with failure to identify the FLA (p < 0.0001). In 18 patients whose tumors involved the PT, only 1 patient had mild preoperative dysphasia. One week after surgery, language function worsened in 4 (22%) of 18 patients. Six months after surgery, 1 (5.6%) of 18 patients had a persistent mild speech deficit. The mean extent of resection was 90% ± 7.1%. Conclusions Identification of the FLA can be difficult in patients with frontal gliomas on the dominant side that involve the PT, but the positive mapping rate of the FLA was 95% in patients without involvement of the PT. These findings are useful for establishing a positive mapping strategy for patients undergoing awake craniotomy for the treatment of frontal gliomas on the dominant side. Thoroughly positive language mapping with subcortical electrical stimulation should be performed in patients without involvement of the PT. More careful continuous neurological monitoring combined with subcortical electrical stimulation is needed when removing dominant-side frontal gliomas that involve the PT.

Predicting sleepiness during an awake craniotomy

OBJECTIVE

An awake craniotomy is a safe neurological surgical technique that minimizes the risk of brain damage. During the course of this surgery, the patient is asked to perform motor or cognitive tasks, but some patients exhibit severe sleepiness. Thus, the present study investigated the predictive value of a patient's preoperative neuropsychological background in terms of sleepiness during an awake craniotomy.

METHODS

Thirty-seven patients with brain tumor who underwent awake craniotomy were included in this study. Prior to craniotomy, the patient evaluated cognitive status, and during the surgery, each patient's performance and attitude toward cognitive tasks were recorded by neuropsychologists.

RESULTS

The present findings showed that the construction and calculation abilities of the patients were moderately correlated with their sleepiness.

CONCLUSION

These results indicate that the preoperative cognitive functioning of patients was related to their sleepiness during the awake craniotomy procedure and that the patients who exhibited sleepiness during an awake craniotomy had previously experienced reduced functioning in the parietal lobe.

Levetiracetam versus phenytoin for seizure prophylaxis during and early after craniotomy for brain tumours: a phase II prospective, randomised study

OBJECTIVE

Phenytoin (PHT) is routinely used for seizure prophylaxis in patients with brain tumours during and after craniotomy, despite incomplete evidence. We performed a prospective, randomised study to investigate the significance of prophylactic use of levetiracetam (LEV), in comparison with PHT, for patients with supratentorial tumours in the perioperative period.

METHODS

Patients were randomised to receive LEV, 500 mg/body every 12 h until postoperative day 7, or PHT, 15-18 mg/kg fosphenytoin followed by 125 mg PHT every 12 h until postoperative day 7. The primary end point was the occurrence of seizures, and secondary end points included the occurrence of haematological and non-haematological adverse events.

RESULTS

One hundred and forty-six patients were randomised to receive LEV (n=73) or PHT (n=73). The incidence of seizures was significantly less in the LEV group (1.4%) compared with the PHT group (15.1%, p=0.005), suggesting benefit of LEV over PHT. The observed OR for being seizure free in the LEV prophylaxis group relative to the PHT group was 12.77 (95% CI 2.39 to 236.71, p=0.001). In a subgroup analysis of patients who did not have seizures before craniotomy, similar results were demonstrated: the incidence of seizures was 1.9% (LEV) and 13.8% (PHT, p=0.034), and OR was 8.16 (95% CI 1.42 to 154.19, p=0.015). LEV was completed in all cases, although PHT was withdrawn in five patients owing to liver dysfunction (1), skin eruption (2) and atrial fibrillation (2).

CONCLUSIONS

Prophylactic use of LEV in the perioperative period is recommended because it is safe and significantly reduces the incidence of seizures in this period.

TRIAL REGISTRATION NUMBER

UMIN13971.

Low Rate of Intraoperative Seizures During Awake Craniotomy in a Prospective Cohort with 374 Supratentorial Brain Lesions: Electrocorticography Is Not Mandatory

OBJECTIVE

Awake craniotomy (AC) in brain lesions has allowed an improvement of both oncologic and functional results. However, intraoperative seizures (IOSs) were reported as a cause of failure of AC. Here, we analyze the incidence, risk factors, and consequences of IOSs in a prospective cohort of 374 ACs without electrocorticography (ECoG).

METHODS

We performed a prospective study including all patients who underwent AC for an intra-axial supratentorial cerebral lesion from 2009-2014 in our department. Occurrence of IOS was analyzed with respect to medical and epilepsy history, tumor characteristics, operative technique, and postoperative outcomes.

RESULTS

The study comprised 374 patients with a major incidence of low-grade glioma (86%). Most of the patients (83%) had epilepsy history before surgery (20% had intractable seizures). Preoperative mean Karnofsky performance scale (KPS) score was 91. IOSs occurred in 13 patients (3.4%). All IOSs were partial seizures, which quickly resolved by irrigation with cold Ringer lactate. No procedure failed because of IOS, and the rate of aborted AC whatever the cause was nil. Mean stimulation current intensity for cortical and subcortical mapping was 2.25 ± 0.6 mA. Presurgical refractory epilepsy was not associated with a higher incidence of IOS. Three months after surgery, no patients had severe or disabling permanent worsening, even within the IOS group (mean KPS score of 93.7).

CONCLUSIONS

AC for intra-axial brain lesion can be safely and reproducibly achieved without ECoG, with a low rate of IOS and excellent functional results, even in patients with preoperative intractable epilepsy.

[Incidence and causes of early end in awake surgery for language mapping not directly related to eloquence]

The incidence and causes that may lead to an early end (unfinished cortical/subcortical mapping) of awake surgery for language mapping are little known. A study was conducted on 41 patients with brain glioma located in the language area that had awake surgery under conscious sedation. Surgery was ended early in 6 patients. The causes were: tonic-clonic seizure (1), lack of cooperation due to fatigue/sleep (4), whether or not word articulation was involved, a decreased level of consciousness for ammonia encephalopathy that required endotracheal intubation (1). There are causes that could be expected and in some cases avoided. Tumour size, preoperative aphasia, valproate treatment, and type of anaesthesia used are variables to consider to avoid failure in awake surgery for language mapping. With these results, the following measures are proposed: l) If the tumour is large, perform surgery in two times to avoid fatigue, 2) if patient has a preoperative aphasia, do not use sedation during surgery to ensure that sleepiness does not cause worse word articulation, 3) if the patient is on valproate treatment, it is necessary to rule out the pre-operative symptoms that are not due to ammonia encephalopathy.

Awake craniotomy to maximize glioma resection: methods and technical nuances over a 27-year period

OBJECT

Awake craniotomy is currently a useful surgical approach to help identify and preserve functional areas during cortical and subcortical tumor resections. Methodologies have evolved over time to maximize patient safety and minimize morbidity using this technique. The goal of this study is to analyze a single surgeon's experience and the evolving methodology of awake language and sensorimotor mapping for glioma surgery.

METHODS

The authors retrospectively studied patients undergoing awake brain tumor surgery between 1986 and 2014. Operations for the initial 248 patients (1986–1997) were completed at the University of Washington, and the subsequent surgeries in 611 patients (1997–2014) were completed at the University of California, San Francisco. Perioperative risk factors and complications were assessed using the latter 611 cases.

RESULTS

The median patient age was 42 years (range 13–84 years). Sixty percent of patients had Karnofsky Performance Status (KPS) scores of 90–100, and 40% had KPS scores less than 80. Fifty-five percent of patients underwent surgery for high-grade gliomas, 42% for low-grade gliomas, 1% for metastatic lesions, and 2% for other lesions (cortical dysplasia, encephalitis, necrosis, abscess, and hemangioma). The majority of patients were in American Society of Anesthesiologists (ASA) Class 1 or 2 (mild systemic disease); however, patients with severe systemic disease were not excluded from awake brain tumor surgery and represented 15% of study participants. Laryngeal mask airway was used in 8 patients (1%) and was most commonly used for large vascular tumors with more than 2 cm of mass effect. The most common sedation regimen was propofol plus remifentanil (54%); however, 42% of patients required an adjustment to the initial sedation regimen before skin incision due to patient intolerance. Mannitol was used in 54% of cases. Twelve percent of patients were active smokers at the time of surgery, which did not impact completion of the intraoperative mapping procedure. Stimulation-induced seizures occurred in 3% of patients and were rapidly terminated with ice-cold Ringer's solution. Preoperative seizure history and tumor location were associated with an increased incidence of stimulation-induced seizures. Mapping was aborted in 3 cases (0.5%) due to intraoperative seizures (2 cases) and patient emotional intolerance (1 case). The overall perioperative complication rate was 10%.

CONCLUSIONS

Based on the current best practice described here and developed from multiple regimens used over a 27-year period, it is concluded that awake brain tumor surgery can be safely performed with extremely low complication and failure rates regardless of ASA classification; body mass index; smoking status; psychiatric or emotional history; seizure frequency and duration; and tumor site, size, and pathology.

Is there a risk of seizures in “preventive” awake surgery for incidental diffuse low-grade gliomas?

OBJECT

Although a large amount of data supports resection for symptomatic diffuse low-grade glioma (LGG), the therapeutic strategy regarding incidental LGG (ILGG) is still a matter of debate. Indeed, early “preventive” surgery has recently been proposed in asymptomatic patients with LGG, after showing that the extent of resection was larger than in symptomatic patients with LGG. However, the quality of life should be preserved by avoiding both neurological deficit and epilepsy. The aim of this study was to determine the risk of seizures related to such a prophylactic surgical treatment in ILGG.

METHODS

The authors report a prospective series of 21 patients with ILGG who underwent awake surgery with a minimum follow-up of 20 months following resection. Data regarding clinicoradiological features, surgical procedures, and outcomes were collected and analyzed. In particular, the eventual occurrence and type of seizures in the intra- and postoperative periods were studied, as follows: early (< 3 months) and long-term (until last follow-up) periods.

RESULTS

There were no intraoperative seizures in this series. During the early postoperative period, the authors observed only a single episode of partial seizures in a patient with no antiepileptic drug (AED) prophylaxis—all other patients were given antiepileptic treatment following resection. The AEDs were discontinued in all cases, with a mean delay of 8 months after surgery (range 3–24 months). No patient had permanent neurological deficits. All 21 patients returned to an active familial, social, and professional life (working full time in all cases). Total or even “supratotal” resection (the latter meaning that a margin around the tumor visible on FLAIR-weighted MRI was removed) was achieved in 14 cases (67%). In 7 patients (33%) subtotal resection was performed, with a mean residual tumor volume of 1.5 ml (range 1–7 ml). No oncological treatment was administered in the postsurgical period. The mean follow-up after surgery was 49 months (range 20–181 months). Only 2 patients had seizures during the long-term follow-up. Indeed, due to tumor progression after incomplete resection, seizures occurred in 2 cases, 39 and 78 months postsurgery, leading to administration of AEDs and adjuvant treatment. So far, all patients are still alive and enjoy a normal life.

CONCLUSIONS

The risk of inducing seizures is very low in ILGG, and it does not represent an argument against early surgery. These data strongly support the proposal of a screening policy for LGG that will evolve toward a preventive treatment in a more systematic manner.

Ammonia encephalopathy and awake craniotomy for brain language mapping: cause of failed awake craniotomy

We report the case of an aborted awake craniotomy for a left frontotemporoinsular glioma due to ammonia encephalopathy on a patient taking Levetiracetam, valproic acid and clobazam. This awake mapping surgery was scheduled as a second-stage procedure following partial resection eight days earlier under general anesthesia. We planned to perform the surgery with local anesthesia and sedation with remifentanil and propofol. After removal of the bone flap all sedation was stopped and we noticed slow mentation and excessive drowsiness prompting us to stop and control the airway and proceed with general anesthesia. There were no post-operative complications but the patient continued to exhibit bradypsychia and hand tremor. His ammonia level was found to be elevated and was treated with an infusion of l-carnitine after discontinuation of the valproic acid with vast improvement. Ammonia encephalopathy should be considered in patients treated with valproic acid and mental status changes who require an awake craniotomy with patient collaboration.

Evaluation of Language Function under Awake Craniotomy

Awake craniotomy is the only established way to assess patients' language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients' language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients' preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques.

Brain surface reformatted imaging (BSRI) for intraoperative neuronavigation in brain tumor surgery

BACKGROUND

For safe resection of lesions situated in or near eloquent brain regions, determination of their spatial and functional relationship is crucial. Since functional magnetic resonance imaging and intraoperative neurophysiological mapping are not available in all neurosurgical departments, we aimed to evaluate brain surface reformatted imaging (BSRI) as an additional display mode for neuronavigation.

METHODS

Eight patients suffering from perirolandic tumors were preoperatively studied with MRI and navigated transcranial magnetic stimulation (nTMS). Afterwards, the MRI was automatically transformed into BSR images in neuronavigation software (Brainlab, Brainlab AG, Feldkirchen, Germany). One experienced neuroradiologist, one experienced neurosurgeon, and two residents determined hand representation areas ipsilateral to each tumor on two-dimensional (2D) MR images and on BSR images. All results were compared to results from intraoperative direct cortical mapping of the hand motor cortex and to preoperative nTMS results.

RESULTS

Findings from nTMS and intraoperative direct cortical mapping of the hand motor cortex were congruent in all cases. Hand representation areas were correctly determined on BSR images in 81.3 % and on 2D-MR images in 93.75 % (p = 0.26). In a subgroup analysis, experienced observers showed more familiarity with BSRI than residents (96.9 vs. 84.4 % correct results, p = 0.19), with an equal error rate for 2D-MRI. The time required to define hand representation areas was significantly shorter using BSRI than using standard MRI (mean 27.4 vs. 40.4 s, p = 0.04).

CONCLUSIONS

With BSRI, a new method for neuronavigation is now available, allowing fast and easy intraoperative localization of distinct brain regions.

Awake craniotomy: analysis of complicated cases

Awake craniotomy is recognized as method that can decrease the frequency of neurological complications after surgery for gliomas located near eloquent brain regions. Unfortunately good neurological outcome can't be ensured even by using of this technique. This paper discusses reasons and possible ways of prevention of such complications.

MATERIAL AND METHODS

162 awake craniotomies were performed in our clinic.

RESULTS

152 of patients were discharged from the clinic with good outcome. In 10 (6%) cases sustained severe neurological deficit was noted. These complications were associated with anatomic or ischemic injury of subcortical pathways and internal capsule.

CONCLUSION

Awake craniotomy is effective instrument of brain language mapping and prevention of neurological deterioration. Severe neurological complications of awake craniotomy are associated with underestimate neurosurgical risks, especially in terms of blood vessel injury and depth of resection. The main way of prevention of such complications is meticulous planning of operation and adequate using of mapping facilities.

Awake craniotomy for brain tumor: indications, technique and benefits

Increasing interest in the quality of life of patients after treatment of brain tumors has led to the exploration of methods that can improve intraoperative assessment of neurological status to avoid neurological deficits. The only method that can provide assessment of all eloquent areas of cerebral cortex and white matter is brain mapping during awake craniotomy. This method helps ensure that the quality of life and the neuro-oncological result of treatment are not compromised. Apart from the medical aspects of awake surgery, its economic issues are also favorable. Here, we review the main aspects of awake brain tumor surgery. Neurosurgical, neuropsychological, neurophysiological and anesthetic issues are briefly discussed.

Tumor location and IDH1 mutation may predict intraoperative seizures during awake craniotomy

OBJECT

Intraoperative seizures during awake craniotomy may interfere with patients' ability to cooperate throughout the procedure, and it may affect their outcome. The authors have assessed the occurrence of intraoperative seizures during awake craniotomy in regard to tumor location and the isocitrate dehydrogenase 1 (IDH1) status of the tumor.

METHODS

Data were collected in 137 consecutive patients who underwent awake craniotomy for removal of a brain tumor. The authors performed a retrospective analysis of the incidence of seizures based on the tumor location and its IDH1 mutation status, and then compared the groups for clinical variables and surgical outcome parameters.

RESULTS

Tumor location was strongly associated with the occurrence of intraoperative seizures. Eleven patients (73%) with tumor located in the supplementary motor area (SMA) experienced intraoperative seizures, compared with 17 (13.9%) with tumors in the other three non-SMA brain regions (p < 0.0001). Interestingly, there was no significant association between history of seizures and tumor location (p = 0.44). Most of the patients (63.6%) with tumor in the SMA region harbored an IDH1 mutation compared with those who had tumors in non-SMA regions. Thirty-one of 52 patients (60%) with a preoperative history of seizures had an IDH1 mutation (p = 0.02), and 15 of 22 patients (68.2%) who experienced intraoperative seizures had an IDH1 mutation (p = 0.03). In a multivariate analysis, tumor location was found as a significant predictor of intraoperative seizures (p = 0.002), and a trend toward IDH1 mutation as such a predictor was found as well (p = 0.06). Intraoperative seizures were not associated with worse outcome.

CONCLUSIONS

Patients with tumors located in the SMA are more prone to develop intraoperative seizures during awake craniotomy compared with patients who have a tumor in non-SMA frontal areas and other brain regions. The IDH1 mutation was more common in SMA region tumors compared with other brain regions, and may be an additional risk factor for the occurrence of intraoperative seizures.

Intraoperative cortico-cortical evoked potentials for the evaluation of language function during brain tumor resection: initial experience with 13 cases

OBJECTIVES

The objective in the present study was to evaluate the usefulness of cortico-cortical evoked potentials (CCEP) monitoring for the intraoperative assessment of speech function during resection of brain tumors.

METHODS

Intraoperative monitoring of CCEP was applied in 13 patients (mean age 34 ± 14 years) during the removal of neoplasms located within or close to language-related structures in the dominant cerebral hemisphere. For this purpose strip electrodes were positioned above the frontal language area (FLA) and temporal language area (TLA), which were identified with direct cortical stimulation and/or preliminary mapping with the use of implanted chronic subdural grid electrodes. The CCEP response was defined as the highest observed negative peak in either direction of stimulation. In 12 cases the tumor was resected during awake craniotomy.

RESULTS

An intraoperative CCEP response was not obtained in one case because of technical problems. In the other patients it was identified from the FLA during stimulation of the TLA (7 cases) and from the TLA during stimulation of the FLA (5 cases), with a mean peak latency of 83 ± 15 msec. During tumor resection the CCEP response was unchanged in 5 cases, decreased in 4, and disappeared in 3. Postoperatively, all 7 patients with a decreased or absent CCEP response after lesion removal experienced deterioration in speech function. In contrast, in 5 cases with an unchanged intraoperative CCEP response, speaking abilities after surgery were preserved at the preoperative level, except in one patient who experienced not dysphasia, but dysarthria due to pyramidal tract injury. This difference was statistically significant (p < 0.01). The time required to recover speech function was also significantly associated with the type of intraoperative change in CCEP recordings (p < 0.01) and was, on average, 1.8 ± 1.0, 5.5 ± 1.0, and 11.0 ± 3.6 months, respectively, if the response was unchanged, was decreased, or had disappeared.

CONCLUSIONS

Monitoring CCEP is feasible during the resection of brain tumors affecting language-related cerebral structures. In the intraoperative evaluation of speech function, it can be a helpful adjunct or can be used in its direct assessment with cortical and subcortical mapping during awake craniotomy. It can also be used to predict the prognosis of language disorders after surgery and decide on the optimal resection of a neoplasm.

Summary of 15 years experience of awake surgeries for neuroepithelial tumors in tohoku university

We retrospectively analyzed 15 years experience of awake surgeries for neuroepithelial tumors in Tohoku University. Awake surgeries mostly for language mapping were performed for 42 of 681 newly diagnosed cases (6.2%) and 59 of 985 surgeries including for recurrence (6.0%). When the same histologies and locations as cases resected under awake condition are selected from the parent population treated by radical resection, awake surgeries were most frequently performed for 14 of 55 newly diagnosed cases (25.5%) and 14 of 62 surgeries (22.6%) with grade II gliomas. In the results, 8 of 59 surgeries (13.6%) could not achieve complete language monitoring until the final stage of tumor resection, considered as failed awake surgery. Gross total resection was accomplished in 20 of 42 newly diagnosed cases (47.6%) and 32 of 59 surgeries (54.2%). Mortality rate was 0%. Late severe deficits were observed in 2 of 42 newly diagnosed cases (4.8%) and 3 of 59 surgeries (5.1%). Negative language mapping cases did not suffer severe deficits in both early and late stages. In contrast, high incidence of severe deficits, 3 as early and 2 as late of 8 cases, were identified with failed awake surgery. The overall survival of patients treated by awake surgery compared favorably with those treated without stimulation mapping and with stimulation mapping under general anesthesia. Awake surgery may contribute to improve the outcome of gliomas near eloquent areas by maximizing the tumor resection and minimizing the surgical morbidity.

Challenges in pediatric neuroanesthesia: awake craniotomy, intraoperative magnetic resonance imaging, and interventional neuroradiology

This article gives a review of 3 challenges in caring for children undergoing neurosurgical and neurointerventional procedures. Anesthesiologists may have experience with certain aspects of these situations but may not have extensive experience with each clinical setting. This review addresses issues with awake craniotomy, intraoperative magnetic resonance imaging, and neurointerventional procedures in children with neurologic disease. Familiarization with these complex clinical scenarios and their unique considerations allows the anesthesiologist to deliver optimal care and helps facilitate the best possible outcome for these patients.

Awake craniotomy for brain lesions within and near the primary motor area: A retrospective analysis of factors associated with worsened paresis in 102 consecutive patients

Background:

We analyzed factors associated with worsened paresis in a large series of patients with brain lesions located within or near the primary motor area (M1) to establish protocols for safe, awake craniotomy of eloquent lesions.

Methods:

We studied patients with brain lesions involving M1, the premotor area (PMA) and the primary sensory area (S1), who underwent awake craniotomy (n = 102). In addition to evaluating paresis before, during, and one month after surgery, the following parameters were analyzed: Intraoperative complications; success or failure of awake surgery; tumor type (A or B), tumor location, tumor histology, tumor size, and completeness of resection.

Results:

Worsened paresis at one month of follow-up was significantly associated with failure of awake surgery, intraoperative complications and worsened paresis immediately after surgery, which in turn was significantly associated with intraoperative worsening of paresis. Intraoperative worsening of paresis was significantly related to preoperative paresis, type A tumor (motor tract running in close proximity to and compressed by the tumor), tumor location within or including M1 and partial removal (PR) of the tumor.

Conclusions:

Successful awake surgery and prevention of deterioration of paresis immediately after surgery without intraoperative complications may help prevent worsening of paresis at one month. Factors associated with intraoperative worsening of paresis were preoperative motor deficit, type A and tumor location in M1, possibly leading to PR of the tumor.

Intraoperative Seizures During Awake Craniotomy

BACKGROUND:

Awake craniotomy (AC) for removal of intra-axial brain tumors is a well-established procedure. However, the occurrence and consequences of intraoperative seizures during AC have not been well characterized.

OBJECTIVE:

To analyze the incidence, risk factors, and consequences of seizures during AC.

METHODS:

The database of AC at Tel Aviv Medical Center between 2003 to 2011 was reviewed. Occurrences of intraoperative seizures were analyzed with respect to medical history, medications, tumor characteristics, and postoperative outcome.

RESULTS:

Of the 549 ACs performed during the index period, 477 with complete records were identified. Sixty patients (12.6%) experienced intraoperative seizures. The AC procedure failed in 11 patients (2.3%) due to seizures. Patients with intraoperative seizures were significantly younger than nonseizing patients (45 ± 14 years vs 52 ± 16 years, P = .003), had a higher incidence of frontal lobe involvement (86% vs % 57%, P &lt; .0001), and had higher prevalence of a history of seizures (P = .008). Short-term motor deterioration developed postoperatively in a higher percentage of patients with intraoperative seizures (20% vs 10.1%, P = .02) with a longer hospitalization period (4.0 ± 3.0 days vs 3.0 ± 3.0 days, P = .045).

CONCLUSION:

Although in most cases intraoperative seizures will not result in AC failure, the surgical team should be prepared to treat them promptly to avoid intractable seizures. Intraoperative seizures are more common in younger patients with a tumor in the frontal lobe and those with a history of seizures. Moreover, they are associated with a higher incidence of transient postoperative motor deterioration and protracted length of hospital stay.

Outcome of elderly patients undergoing awake-craniotomy for tumor resection

BACKGROUND

Awake-craniotomy allows maximal tumor resection, which has been associated with extended survival. The feasibility and safety of awake-craniotomy and the effect of extent of resection on survival in the elderly population has not been established. The aim of this study was to compare surgical outcome of elderly patients undergoing awake-craniotomy to that of younger patients.

METHODS

Outcomes of consecutive patients younger and older than 65 years who underwent awake-craniotomy at a single institution between 2003 and 2010 were retrospectively reviewed. The groups were compared for clinical variables and surgical outcome parameters, as well as overall survival.

RESULTS

A total of 334 young (45.4 ± 13.2 years, mean ± SD) and 90 elderly (71.7 ± 5.1 years) patients were studied. Distribution of gender, mannitol treatment, hemodynamic stability, and extent of tumor resection were similar. Significantly more younger patients had a better preoperative Karnofsky Performance Scale score (>70) than elderly patients (P = 0.0012). Older patients harbored significantly more high-grade gliomas (HGG) and brain metastases, and fewer low-grade gliomas (P < 0.0001). No significantly higher rate of mortality, or complications were observed in the elderly group. Age was associated with increased length of stay (4.9 ± 6.3 vs. 6.6 ± 7.5 days, P = 0.01). Maximal extent of tumor resection in patients with HGG was associated with prolonged survival in the elderly patients.

CONCLUSIONS

Awake-craniotomy is a well-tolerated and safe procedure, even in elderly patients. Gross total tumor resection in elderly patients with HGG was associated with prolonged survival. The data suggest that favorable prognostic factors for patients with malignant brain tumors are also valid in elderly patients.