Incidence and Risk Factors for Intraoperative Seizures During Elective Craniotomy

Risk factors for thrombocytopenia associated with intravenous valproic acid therapy in pediatric patients undergoing neurosurgical operations

Thrombocytopenia is one of the side effects of VPA. This study aimed to evaluate the incidence and risk factors of thrombocytopenia after intravenous VPA treatment in children with neurosurgical operations. Pediatric patients undergoing neurosurgical operations treated with intravenous VPA were enrolled in this retrospective study. According to platelet count after intravenous injection of VPA, the pediatric patients were divided into the thrombocytopenia group and the non-thrombocytopenia group. Binary logistic regression analysis was used to explore the risk factors for thrombocytopenia. A total of 252 children with neurosurgical operations were included in this study, and the incidence of thrombocytopenia was 12.3% (31/252). Univariate analysis showed that baseline platelet count, duration of VPA therapy, and blood loss were associated with the occurrence of thrombocytopenia after intravenous administration of VPA. Binary logistic regression revealed that baseline platelet count (OR 0.995, 95% CI 0.991-0.999) and blood loss (OR 0.995, 95% CI 0.991-0.999) were independent risk factors for thrombocytopenia after intravenous VPA in children undergoing neurosurgical operations. Our data show that thrombocytopenia is common in neurosurgical operations children treated with intravenous VPA, and that baseline platelet count is an independent risk factor for thrombocytopenia. Regular monitoring of baseline platelet count is important for whether to short-term prophylactic use intravenous VPA in children undergoing neurosurgical operations.

American Clinical Neurophysiology Society Technical Standards for Electrical Stimulation With Intracranial Electrodes for Functional Brain Mapping and Seizure Induction

PURPOSE

These American Clinical Neurophysiology Society technical standards suggest best practices for electrical stimulation mapping (ESM) with subdural and stereotactic depth electrodes for seizure induction and mapping of brain function.

METHODS

A working group was convened from American Clinical Neurophysiology Society membership with expertise in ESM. PubMed searches were performed to identify pertinent peer-reviewed literature. Recurrent meetings reviewed progress, built consensus by discussion, and developed evidence-based recommendations to the extent possible.

RECOMMENDATIONS

Stimulators used for ESM should have sufficient dynamic range, ability to interrupt a stimulus train, and ictal disrupt mechanism(s). Charge density should be calculated for the specific electrodes and ESM settings, the maximum safe limits being 52 to 57 μC/cm 2 /phase for subdural electrodes and not established for stereotactic depth electrodes. Subdural ESM for functional mapping is typically performed at 50-Hz pulse frequency, 200- to 300-µs pulse width, 2- to 8-s train duration, and 1- to 20-mA current strength. Stereo ESM is commonly performed using 2 different pulse frequencies: 1 Hz (300-500 µs pulse width, train duration up to 30 s, and often a constant current of 3-5 mA), and 50 Hz (100-500 µs pulse width, train duration 2-8 s, and 0.5-10 mA current intensity).

CONCLUSIONS

This guideline provides technical standards for the performance of ESM, which will likely evolve over time with advances in technology and additional evidence (also see Graphical Abstract).

Enhanced recovery after surgery (ERAS) for craniotomies in the treatment of brain tumors: A systematic review

INTRODUCTION

Postoperative complications after craniotomy for brain tumors include pain, nausea/vomiting, and infection. A standardized enhanced recovery after surgery (ERAS) protocol is not widely accepted for this common neurosurgical procedure. Few studies have explored its application.

METHODS

A literature search of PubMed, Cochrane, and Google Scholar databases was performed between January 1992 and March 2023. Original studies that implemented an ERAS protocol for patients that underwent craniotomy for brain tumors were included. The following variables were evaluated: hospital length of stay (LOS), postoperative pain, postoperative nausea and vomiting (PONV) prophylaxis, non-opioid analgesia, and quality of life (QOL).

RESULTS

Twelve studies with a total of 1309 patients met inclusion criteria, including ten randomized controlled trials, one nonrandomized controlled trial, and one quality control study. Most frequently assessed metrics included hospital LOS, PONV prophylaxis, and non-opioid analgesia. A significant reduction in postoperative LOS was observed in 7 studies with ERAS or ERAS components. ERAS was significantly associated with pain reduction on the visual analog scale and verbal numerical rating scale (n=8). Non-opioid analgesia in ERAS improved postoperative pain control (n=4) and decreased the duration of pain (n=1). Three of six studies found no difference in PONV in ERAS vs. control. No studies reported an increase in postoperative complications using ERAS vs. control. One study showed greater patient satisfaction at 30-day follow-up with improved QOL.

CONCLUSION

Implementing ERAS protocol may enhance outcomes and quality of life in patients with moderate evidence for improved recovery in those undergoing craniotomy for brain tumors.

Development of Consensus-Based Recommendations to Prevent/Minimize Medication Errors in the Perioperative Care of Patients with Epilepsy: A Mixed-Method

BACKGROUND

This study explored medication errors in the perioperative care of patients with epilepsy and developed consensus-based recommendations to prevent/minimize these errors.

METHODS

A mixed method was used in this study. Medication error situations were explored in semi-structured in-depth interviews with nurses (n = 12), anesthesiologists (n = 5), anesthesia technicians (n = 5), surgeons (n = 4), neurologists (n = 4), and patients with epilepsy (n = 10). The qualitative data were analyzed using the qualitative interpretive description approach. A two-round Delphi technique was used among nurses (n = 22), anesthesiologists (n = 9), anesthesia technicians (n = 7), surgeons (n = 7), and neurologists (n = 5).

RESULTS

A total of 1400 minutes of interview time was analyzed in this study. Of the panelists, 39 (78.0%) agreed that patients with epilepsy present unique challenges to providers of perioperative care that make them prone to medication errors. The interviewees in this study described 32 different medication error situations that occurred while providing perioperative care services to patients with epilepsy. In this study, 35 consensus-based recommendations to prevent/minimize medication errors in the perioperative care of patients with epilepsy were developed.

CONCLUSIONS

The findings of this study are informative to decision-makers in health care facilities and other stakeholders in health regulatory authorities who need to design measures to prevent/minimize medication errors and improve perioperative outcomes of patients with epilepsy. Studies are needed to investigate if these recommendations can be effective in preventing/reducing medication errors in the perioperative care of patients with epilepsy.

Analysis of Demographics and Outcomes of Surgical Resection in the Central Nervous System of Patients With Metastatic Melanoma

Background

Patients with melanoma frequently develop central nervous system metastases. Oligometastatic disease is often treated either by surgical resection or by stereotactic radiotherapy. This study investigates the trends and clinical outcomes of patients with melanoma who have undergone surgical procedures on the central nervous system during their hospitalization.

Methods

A retrospective study was performed based on admissions of adult patients who underwent craniotomy for metastatic melanoma from 2000 to 2014 using the Nationwide Inpatient Sample database. The primary outcome measure was all-cause in-hospital mortality. Secondary outcomes included hospital length of stay (LOS) and discharge disposition (home/home with health care and skilled nursing facilities/long-term acute care (SNFs/LTAC)). Factors associated with in-hospital mortality were examined by multivariable logistic regression. We adjusted for patient and hospital characteristics, payer, and comorbid conditions. We also examined trends of mortality for the study years.

Results

There were an estimated 1,216 discharges of patients with melanoma undergoing craniotomy during the study period. Patients undergoing surgical interventions were typically males (69%) and whites (79%). Ninety-eight percent of procedures were performed at teaching hospitals. Unadjusted all-cause in-hospital mortality was 3.1%. There was no significant difference in mortality over 13 years. Age, gender, and race were not associated with increased in-hospital mortality. LOS was longer in elderly and those with higher Charlson Comorbidity Index. Of the survivors, 76% were discharged to home or with home healthcare while 24% were discharged to SNFs/LTAC. Patients with age > 65 (odds ratio (OR): 2.9; 95% confidence interval (CI): 2.2 - 3.9, P < 0.001) and those with higher Charlson Comorbidity Index (OR: 1.2; 95% CI: 1.1 - 1.3) had higher odds for being discharged to SNFs/LTAC.

Conclusions

Patients who undergo craniotomy for metastatic melanoma have a low in-hospital mortality rate. One quarter of patients were discharged to SNFs/LTAC.

Levetiracetam for Seizure Prophylaxis in Neurocritical Care: A Systematic Review and Meta-analysis

BACKGROUND

Levetiracetam is commonly used for seizure prophylaxis in patients with intracerebral hemorrhage (ICH), traumatic brain injury (TBI), supratentorial neurosurgery, and spontaneous subarachnoid hemorrhage (SAH). However, its efficacy, optimal dosing, and the adverse events associated with levetiracetam prophylaxis remain unclear.

METHODS

A systematic search of PubMed, Embase, and Cochrane central register of controlled trials (CENTRAL) database was conducted from January 1, 2000, to October 30, 2020, including articles addressing treatment with levetiracetam for seizure prophylaxis after SAH, ICH, TBI, and supratentorial neurosurgery. Non-English, pediatric (aged < 18 years), preclinical, reviews, case reports, and articles that included patients with a preexisting seizure condition or epilepsy were excluded. The coprimary meta-analyses examined first seizure events in (1) levetiracetam versus no antiseizure medication and (2) levetiracetam versus other antiseizure medications in all ICH, TBI, SAH, and supratentorial neurosurgery populations. Secondary meta-analyses evaluated the same comparator groups in individual disease populations. Risk of bias in non-randomised studies - of interventions (ROBINS-I) and risk-of-bias tool for randomized trials (RoB-2) tools were used to assess risk of bias.

RESULTS

A total of 30 studies (n = 6 randomized trials, n = 9 prospective studies, and n = 15 retrospective studies), including 7609 patients (n = 4737 with TBI, n = 701 with SAH, n = 261 with ICH, and n = 1910 with neurosurgical diseases) were included in analyses. Twenty-seven of 30 (90%) studies demonstrated moderate to severe risk of bias, and 11 of 30 (37%) studies used low-dosage levetiracetam (250-500 mg twice daily). In the primary meta-analyses, there were no differences in seizure events for levetiracetam prophylaxis (n = 906) versus no antiseizure medication (n = 2728; odds ratio [OR] 0.79, 95% confidence interval [CI] 0.53-1.16, P = 0.23, fixed-effect, I² = 26%, P = 0.23 for heterogeneity) or levetiracetam (n = 1950) versus other antiseizure prophylaxis (n = 2289; OR 0.84, 95% CI 0.55-1.28, P = 0.41, random-effects, I² = 49%, P = 0.005 for heterogeneity). Only patients with supratentorial neurosurgical diseases benefited from levetiracetam compared with other antiseizure medications (median 0.70 seizure events per-patient-year with levetiracetam versus 2.20 seizure events per-patient-year for other antiseizure medications, OR 0.34, 95% CI 0.20-0.58, P < 0.001, fixed-effects, I² = 39%, P = 0.13 for heterogeneity). There were no significant differences in meta-analyses of patients with ICH, SAH, or TBI. Adverse events of any severity were reported in a median of 8% of patients given levetiracetam compared with 21% of patients in comparator groups.

CONCLUSIONS

Based on the current moderately to seriously biased heterogeneous data, which frequently used low and possibly subtherapeutic doses of levetiracetam, our meta-analyses did not demonstrate significant reductions in seizure incidence and neither supports nor refutes the use of levetiracetam prophylaxis in TBI, SAH, or ICH. Levetiracetam may be preferred post supratentorial neurosurgery. More high-quality randomized trials of prophylactic levetiracetam are warranted.

Bilateral Bispectral Index Monitoring Performance in the Detection of Seizures in Nonanesthetized Epileptic Patients: An Observational Study

BACKGROUND

The aim of this observational study was to determine whether bilateral bispectral index (BIS) monitoring can detect seizures in epileptic patients.

METHODS

Four-channel frontal BIS monitoring and standard 40-channel electroencephalography monitoring were conducted in epileptic patients undergoing evaluation for epilepsy surgery. The BIS numerical value, signal quality index, electromyography, suppression ratio, and color density spectral array were continuously recorded. In patients with electroencephalography-confirmed seizures, the mean value and trend (slope of linear regression) of bilateral BIS monitor parameters were analyzed from 1 minute before to 1 minute after seizure onset.

RESULTS

Of 48 patients included in the study, 21 (43.8%) had at least 1 seizure. BIS numerical value was not able to detect focal or focal to bilateral tonic-clonic seizures. Considering all seizures, the only significant differences between recordings 1 minute before and 1 minute after seizure onset were a decrease in the signal quality index slope from 1 hemisphere (0.039±0.297 vs. -0.085±0.321, respectively; P=0.029) and in the mean signal quality index recorded from both hemispheres (left hemisphere: 65.775±30.599 vs. 61.032±26.285; P=0.016 and right hemisphere: 63.244±31.985 vs. 59.837±27.360; 0.029); these differences were not maintained after Hochberg adjustment for multiple comparisons. In seizures occurring during sleep, there was a change in the electromyography slope of 1 hemisphere before and after seizure onset (-0.141±0.176 vs. 0.162±0.140, respectively; P=0.038). There were variable responses in BIS parameters in the 3 patients who developed focal nonconvulsive seizure clusters.

CONCLUSION

Bilateral BIS monitoring was not able to detect the occurrence of seizures in epileptic patients.

Analysis of risk factors and clinical sequelae of direct electrical cortical stimulation-induced seizures and afterdischarges in patients undergoing awake mapping

OBJECTIVE

Intraoperative stimulation has emerged as a crucial adjunct in neurosurgical oncology, aiding maximal tumor resection while preserving sensorimotor and language function. Despite increasing use in clinical practice of this stimulation, there are limited data on both intraoperative seizure (IS) frequency and the presence of afterdischarges (ADs) in patients undergoing such procedures. The objective of this study was to determine risk factors for IS or ADs, and to determine the clinical consequences of these intraoperative events.

METHODS

A retrospective chart review was performed for patients undergoing awake craniotomy (both first time and repeat) at a single institution from 2013 to 2018. Hypothesized risk factors for ADs/ISs in patients were evaluated for their effect on ADs and ISs, including tumor location, tumor grade (I-IV), genetic markers (isocitrate dehydrogenase 1/2, O 6-methylguanine-DNA methyltransferase [MGMT] promoter methylation, chromosome 1p/19q codeletion), tumor volume, preoperative seizure status (yes/no), and dosage of preoperative antiepileptic drugs for each patient. Clinical outcomes assessed in patients with IS or ADs were duration of surgery, length of stay, presence of perioperative deficits, and postoperative seizures. Chi-square analysis was performed for binary categorical variables, and a Student t-test was used to assess continuous variables.

RESULTS

A total of 229 consecutive patients were included in the analysis. Thirty-five patients (15%) experienced ISs. Thirteen (37%) of these 35 patients had experienced seizures that were appreciated clinically and noted on electrocorticography simultaneously, while 8 patients (23%) experienced ISs that were electrographic alone (no obvious clinical change). MGMT promoter methylation was associated with an increased prevalence of ISs (OR 3.3, 95% CI 1.2-7.8, p = 0.02). Forty patients (18%) experienced ADs. Twenty-three percent of patients (9/40) with ISs had ADs prior to their seizure, although ISs and ADs were not statistically associated (p = 0.16). The presence of ADs appeared to be correlated with a shorter length of stay (5.1 ± 2.6 vs 6.1 ± 3.7 days, p = 0.037). Of the clinical features assessed, none were found to be predictive of ADs. Neither IS nor AD, or the presence of either IS or AD (65/229 patients), was a predictor for increased length of stay, presence of perioperative deficits, or postoperative seizures.

CONCLUSIONS

ISs and ADs, while commonly observed during intraoperative stimulation for brain mapping, do not negatively affect patient outcomes.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

Multimodal monitoring to aid detection and management of intraoperative seizures: a case report

One of the primary goals in Neuroanesthesia is to preserve cerebral oxygenation and protect the brain from secondary injuries. Seizures have severe implications in the intraoperative period, as it can instigate an increase in cerebral metabolism and oxygen demand, thus causing cerebral hypoxia. Detection of intraoperative seizures is imperative in neurosurgical cases as the ramifications of intracranial hypertension and cerebral hypoxia caused by it can affect patient prognosis and perioperative outcomes. We report a case of detecting intraoperative seizures with the aid of patient state index and near infrared spectroscopy. Multi-modality monitoring aided in the management of a time-sensitive complication, which could otherwise have possibly led to secondary brain insult.

A case report of several intraoperative convulsions while using the Narcotrend monitor: Significance and predictive use

INTRODUCTION

Intraoperative seizures under general anesthesia are rare and our observation is the first to demonstrate a distinct electroencephalogram (EEG) pattern on the Narcotrend monitor.

PATIENT CONCERNS

We present the case of a 30-year-old man undergoing craniotomy for glioblastoma resection under general anesthesia who suffered tonic-clonic seizures captured in a specific pattern by the intraoperative EEG.

DIAGNOSES

Our depth of anesthesia monitor recorded, before the seizure, a widening of the beta-wave performance in a distinct "triangular-shaped" pattern. This pattern was repeated before the second seizure. The patient had no previous history of seizures and following surgery no further seizures were recorded.

INTERVENTIONS

A spectrogram analysis showed a distinct increase in mean absolute beta power immediately prior to the first seizure. The EEG immediately prior to the second seizure was characterized by broadband noise. Both seizures were characterized by increased mean absolute delta, theta, and beta power.

OUTCOMES

The increase in EEG beta activity seen before the tonic-clonic movements may represent cortical irritability secondary to surgical manipulation, induced by electrical stimulation, reflecting progressive brain over-arousal. The attentive analysis of the relative beta power may have helped forecast the occurrence of the second seizure.

LESSONS

We report the use of a simple, inexpensive, and portable EEG-based monitoring device to assist seizure detection and decision making.