Seizures and Epileptiform Discharges in Patients With Acute Subdural Hematoma

The Long-Term Use of Diagnostic Subdural Electroencephalogram Electrodes and Subdural Hematoma: A Prospective Cohort Study

OBJECTIVES

Seizures and status epilepticus (SE) are frequent complications of acute subdural hematoma (aSDH) associated with increased morbidity and mortality. Therefore, we aimed to evaluate whether invasive subdural electroencephalogram recording leads to earlier seizure detection and treatment initiation in patients with aSDH.

DESIGN

Prospective, single-center, cohort trial.

SETTING

Neurologic and neurosurgical ICUs of one academic hospital in Germany.

PATIENTS

Patients with aSDH undergoing surgical treatment. In total, 76 patients were enrolled in this study, 31 patients (40.8%) were assigned to the invasive electroencephalogram (iEEG) monitoring group and 45 patients (59.2%) to control group.

INTERVENTIONS

The electrode group was implanted with a subdural strip electrode providing up to 7 days of real-time electroencephalogram recording in the neurointensive care unit, whereas the control group received regular normal surface electroencephalograms during the 7-day period. The primary outcomes were the prevalence and time to seizures and SE occurrence. Secondary outcomes included neurologic outcomes assessed using the Glasgow Outcome Scale (GOS) at discharge and 6-month follow-up and the prevalence of focal structural epilepsy within 2 years after discharge.

MEASUREMENTS AND MAIN RESULTS

The trial was stopped after a study committee meeting when the prespecified criteria were met. The iEEG and control groups were well-matched for clinical characteristics at admission. Frequencies of seizures and SE detection were significantly higher in the iEEG group than in the control group (61% vs 15.6%; p < 0.001 and 38.7% vs 11.1%; p = 0.005). Time to seizure and SE detection was significantly earlier (median 29.2 vs 83.8 hr; p = 0.018 and 17.2 vs 83.8 hr; p = 0.033) in the iEEG group than in the control group. Favorable outcomes (GOS 4-5) were more frequently achieved in the iEEG group than in the control group (58% vs 31%; p = 0.065). No significant differences were detected in long-term mortality or post-traumatic epilepsy.

CONCLUSIONS

Invasive subdural electroencephalogram monitoring is valuable and safe for early seizure/SE detection and treatment and might improve outcomes in the neurocritical care of patients with aSDH.

Outcomes of patients with nonepileptic transient neurologic symptoms after subdural hematoma evacuation

BACKGROUND

Patients undergoing a subdural hematoma (SDH) evacuation can experience transient neurological symptoms (TNS) postoperatively. Electroencephalography (EEG) is used to rule out seizures. We aim to characterize patients with TNS and negative epileptiform activity on EEG and compare them to those with positive epileptiform EEG findings.

METHODS

We performed a retrospective study of adult patients who underwent EEG for evaluation of TNS after undergoing SDH evacuation. Patients were stratified based on SDH type (acute and non-acute) and whether or not their EEG demonstrated positive epileptiform activity. A multivariate analysis was performed to identify predictors of negative EEG findings.

RESULTS

One hundred twenty-nine SDH patients were included (45 (34.9%) acute; 84 (65.1%) non-acute). Overall, 45 (24 acute and 21 non-acute SDH patients) had positive epileptiform EEG findings, and 84 (21 acute and 63 non-acute SDH patients) had a negative EEG. Acute and non-acute SDH patients with positive EEG findings were more likely to suffer from greater than five episodes of TNS, impaired awareness, and motor symptoms, while the negative EEG group was more likely to suffer from negative symptoms. Non-acute SDH patients with positive EEG had longer mean ICU stays (14.6 vs. 7.2; p = 0.005). Both acute and non-acute SDH-positive EEG patients had worse disposition upon discharge (p < 0.05), worse modified Rankin score at discharge (p < 0.05), and 3-month follow-up (p < 0.05) and were more likely to be discharged on more than one antiepileptic drug (p < 0.001).

CONCLUSION

Postoperative acute and non-acute SDH patients with TNS and negative EEG results are likely to have a favorable clinical picture. This distinction is therapeutically and prognostically important as these patients may not respond to typical antiepileptic drugs and they have better functional outcomes.

Role of Brain Natriuretic Peptide in the Prediction of Early Postoperative Seizures Following Surgery for Traumatic Acute Subdural Hematoma: A Prospective Study

INTRODUCTION

Brain natriuretic peptide (BNP) is a reliable biomarker in the acute phase of traumatic brain injury. However, the relationship between BNP and traumatic acute subdural hematoma (aSDH) has not yet been addressed. This study aimed to analyze BNP levels on admission in surgically treated patients and assess their relationship with early postoperative seizures (EPS) and functional outcomes.

METHODS

Patients with unilateral traumatic aSDH who were surgically treated in our department between July 2017 and May 2020 were included in the study. BNP was preoperatively measured. Patients' neurologic condition, radiographic variables on initial cranial computed tomography, sodium serum levels on admission, and occurrence of EPS were prospectively assessed. Functional outcome was assessed using the modified Rankin Scale (mRS) at discharge and follow-up (at 2-3 months). A poor outcome was defined by a mRS score > 3.

RESULTS

EPS occurred in 20 (19.6%) of 102 surgically treated patients in the final cohort on the median day 3. A significant association between EPS and a poor Glasgow Coma Scale score at the 7th postoperative day was found, which in turn independently predicted a poor functional outcome at discharge and follow-up. Nonetheless, EPS were not associated with poor functional outcomes. The multivariate analysis revealed BNP > 95.4 pg/ml (aOR = 5.7, p = 0.003), sodium < 137.5 mmol/l (aOR = 4.6, p = 0.009), and left-sided aSDH (aOR = 4.4, p = 0.020) as independent predictors of EPS.

CONCLUSION

In the early postoperative phase of traumatic aSDH, EPS were associated with worse neurologic conditions, which in turn independently predicted poor outcomes at discharge and follow-up. Although several EPS risk factors have already been elucidated, this study presents BNP as a novel reliable predictor of EPS. Further larger studies are needed to determine whether a more precise estimate of EPS risk using BNP levels can be reached.

Neurologic Complications in the Postoperative Neurosurgery Patient

PURPOSE OF REVIEW

This article discusses neurologic complications encountered in the postoperative care of neurosurgical patients that are common or key to recognize in the immediate postoperative period. The major neurosurgical subspecialty procedures (cerebrovascular neurosurgery, neuro-oncology, epilepsy neurosurgery, functional neurosurgery, CSF diversion, endovascular neurosurgery, and spinal surgery) are broadly included under craniotomy procedures, endovascular/vascular procedures, and spinal procedures. This article focuses on the range of complications inherent in these approaches with specific scenarios addressed as applicable.

RECENT FINDINGS

The morbidity and mortality related to neurosurgical procedures remains high, necessitating ongoing research and quality improvement efforts in perioperative screening, intraoperative management, surgical approaches, and postoperative care of these patients. Emerging research continues to investigate safer and newer options for routine neurosurgical approaches, such as coiling over clipping for amenable aneurysms, endoscopic techniques for transsphenoidal hypophysectomy, and minimally invasive spinal procedures; postoperative monitoring and care of patients after these procedures continues to be a key component in the continuum of care for improving outcomes.

SUMMARY

Postoperative care of patients undergoing major neurosurgical procedures is an integral part of many neurocritical care practices. Neurosurgeons often enlist help from neurologists to assist with evaluation, interpretation, and management of complications in routine inpatient settings. Awareness of the common neurologic complications of various neurosurgical procedures can help guide appropriate clinical monitoring algorithms and quality improvement processes for timely evaluation and management of these patients.

Validation of the 2HELPS2B Seizure Risk Score in Acute Brain Injury Patients

BACKGROUND AND OBJECTIVE

Seizures are common after traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhage (aSAH), subdural hematoma (SDH), and non-traumatic intraparenchymal hemorrhage (IPH)-collectively defined herein as acute brain injury (ABI). Most seizures in ABI are subclinical, meaning that they are only detectable with EEG. A method is required to identify patients at greatest risk of seizures and thereby in need of prolonged continuous EEG monitoring. 2HELPS2B is a simple point system developed to address this need. 2HELPS2B estimates seizure risk for hospitalized patients using five EEG findings and one clinical finding (pre-EEG seizure). The initial 2HELPS2B study did not specifically assess the ABI subpopulation. In this study, we aim to validate the 2HELPS2B score in ABI and determine its relative predictive accuracy compared to a broader set of clinical and electrographic factors.

METHODS

We queried the Critical Care EEG Monitoring Research Consortium database for ABI patients age ≥ 18 with > 6 h of continuous EEG monitoring; data were collected between February 2013 and November 2018. The primary outcome was electrographic seizure. Clinical factors considered were age, coma, encephalopathy, ABI subtype, and acute suspected or confirmed pre-EEG clinical seizure. Electrographic factors included 18 EEG findings. Predictive accuracy was assessed using a machine-learning paradigm with area under the receiver operator characteristic (ROC) curve as the primary outcome metric. Three models (clinical factors alone, EEG factors alone, EEG and clinical factors combined) were generated using elastic-net logistic regression. Models were compared to each other and to the 2HELPS2B model. All models were evaluated by calculating the area under the curve (AUC) of a ROC analysis and then compared using permutation testing of AUC with bootstrapping to generate confidence intervals.

RESULTS

A total of 1528 ABI patients were included. Total seizure incidence was 13.9%. Seizure incidence among ABI subtype varied: IPH 17.2%, SDH 19.1%, aSAH 7.6%, TBI 9.2%. Age ≥ 65 (p = 0.015) and pre-cEEG acute clinical seizure (p < 0.001) positively affected seizure incidence. Clinical factors AUC = 0.65 [95% CI 0.60-0.71], EEG factors AUC = 0.82 [95% CI 0.77-0.87], and EEG and clinical factors combined AUC = 0.84 [95% CI 0.80-0.88]. 2HELPS2B AUC = 0.81 [95% CI 0.76-0.85]. The 2HELPS2B AUC did not differ from EEG factors (p = 0.51), or EEG and clinical factors combined (p = 0.23), but was superior to clinical factors alone (p < 0.001).

CONCLUSIONS

Accurate seizure risk forecasting in ABI requires the assessment of EEG markers of pathologic electro-cerebral activity (e.g., sporadic epileptiform discharges and lateralized periodic discharges). The 2HELPS2B score is a reliable and simple method to quantify these EEG findings and their associated risk of seizure.

Non-electrographic Seizures Due to Subdural Hematoma: A Case Series and Review of the Literature

Seizures due to subdural hematoma (SDH) are a common finding, typically diagnosed using electroencephalography (EEG). At times, aggressive management of seizures is necessary to improve neurologic recovery and outcomes. Here, we present three patients who had undergone emergent SDH evacuation and showed postoperative focal deficits without accompanying electrographic epileptiform activity. After infarction and recurrent hemorrhage were ruled out, seizures were suspected despite a negative EEG. Patients were treated aggressively with AEDs and eventually showed clinical improvement. Long-term monitoring with EEG revealed electrographic seizures in a delayed fashion. EEG recordings are an important tool for seizure detection, but should be used as an adjunct to, rather than a replacement for, the clinical examination in the acute setting. At times, aggressive treatment of suspected postoperative seizures is warranted despite lack of corresponding electrographic activity and can improve clinical outcomes.

Significant increase in acute subdural hematoma in octo- and nonagenarians: surgical treatment, functional outcome, and predictors in this patient cohort

OBJECTIVE

Acute subdural hematoma (aSDH) is a common disease increasing in prevalence given the demographic growth of the aging population. Yet, the benefit of surgical treatment for aSDH and the subsequent functional outcome in elderly patients (age ≥ 80 years) remain unclear. Therefore, the aims of this study were to evaluate the incidence of aSDH in patients 80 years or older, determine overall functional outcome, identify predictors of an unfavorable or favorable outcome, and establish specific risk factors for seizures.

METHODS

The authors retrospectively analyzed patients 80 years and older who presented with isolated aSDH in the past 10 years at their institution. The following parameters were assessed: baseline characteristics, clinical status on admission and 24 hours after surgery, and clinical course. Functional outcome was assessed at discharge and the 3-month follow-up (FU).

RESULTS

In the period from January 2007 to December 2016, 165 patients with aSDH were admitted to the authors’ institution. Sixty-eight patients (41.2%) were 80 years old or older, and the mean age overall was 85 years (range 80–96 years). The incidence of aSDH in the elderly had significantly increased over past decade, with more than 50% of patients admitted to our institution for aSDH now being 80 years or older. The overall mortality rate was 28% at discharge and 48% at the FU. Independent predictors of an unfavorable outcome at discharge were a GCS score ≤ 8 at 24 hours after operation (p < 0.001) and pneumonia (p < 0.02). At the FU, a GCS score ≤ 8 at 24 hours after operation (p < 0.001) and cumulative comorbidities (≥ 5; p < 0.05) were significant independent predictors. All patients with more than 6 comorbidities had died by the FU. Surgical treatment in comatose compared to noncomatose patients had statistically significant, higher mortality rates at discharge and the FU. Still, 23% of the comatose patients and more than 50% of the noncomatose patients had a favorable outcome at the FU (p = 0.06).

CONCLUSIONS

The number of octo- and nonagenarians with aSDH significantly increased over the last decade. These patients can achieve a favorable outcome, especially those with a noncomatose status and fewer than 5 comorbidities. Surgical and nonsurgical treatment of octo- and nonagenarians during and after discharge should be optimized to increase clinical improvement.