Acute and Long-Term Outcomes of Lateralized Rhythmic Delta Activity (LRDA) Versus Lateralized Periodic Discharges (LPDs) in Critically Ill Patients

Electrographic Seizures and Predictors of Epilepsy after Pediatric Arteriovenous Malformation Rupture

OBJECTIVES

To assess clinical and electroencephalogram (EEG) predictors of epilepsy and to describe the percentage of electrographic seizures and development of epilepsy among patients with spontaneous intracerebral hemorrhage (ICH) due to arteriovenous malformation (AVM) rupture.

STUDY DESIGN

Retrospective review of patients admitted to the pediatric intensive care unit with ICH secondary to AVM rupture over 11 years. Clinical variables were collected by review of the electronic medical record. Seizures were described as acute symptomatic (7 days after AVM rupture), subacute (7-30 days after AVM rupture) and remote (greater than 30 days after AVM rupture). Outcome metrics included mortality, and the development of epilepsy post discharge. Descriptive statistics were used.

RESULTS

Forty-three patients met inclusion criteria with a median age of 12.2 years (IQR 7.3-14.8) and 49% (21/43) were female. Sixteen percent (7/43) presented with a clinical seizure prior to EEG placement. EEG was performed in 62% (27/43) of patients; one had electrographic status epilepticus without clinical signs. Sixteen percent (7/43) of patients were diagnosed with epilepsy, with a median time to diagnosis of 1.34 years (IQR 0.55-2.07) after AVM rupture. One-year epilepsy-free survival was 84% (95% CI 70%-98%) and 2-year epilepsy-free survival was 79% (95% CI 63%-95%) Remote seizures were associated with epilepsy (P < .001), but acute symptomatic seizures were not (P = .16).

CONCLUSIONS

EEG-confirmed seizures are uncommon in patients with ICH secondary to AVM rupture; however, when identified, the seizure burden appears to be high. Patients with seizures 30 days after AVM rupture are more likely to develop epilepsy.

Lateralized Rhythmic Delta Activity and Lateralized Periodic Discharges in Critically Ill Pediatric Patients

PURPOSE

To evaluate the clinical and electrographic characteristics of critically ill pediatric patients with lateralized rhythmic delta activity (LRDA) and compare them with patients with lateralized periodic discharges (LPDs).

METHODS

This was a retrospective study examining consecutive critically ill pediatric patients (1 month-18 years) with LRDA or LPDs monitored on continuous electroencephalography. Clinical, radiologic, and electrographic characteristics; disease severity; and acute sequelae were compared between the two groups.

RESULTS

Of 668 pediatric patients monitored on continuous electroencephalography during the study period, 12 (1.79%) patients had LRDA and 15 (2.24%) had LPDs. The underlying etiologies were heterogeneous with no difference in the acuity of brain MRI changes between both groups. Lateralized rhythmic delta activity and LPDs were concordant with the side of MRI abnormality in most patients [85.7% (LRDA) and 83.3% (LPD)]. There was no difference in the measures of disease severity between both groups. Seizures were frequent in both groups (42% in the LRDA group and 73% in the LPD group). Patients in the LPD group had a trend toward requiring a greater number of antiseizure medications for seizure control (median of 4 vs. 2 in the LRDA group, p = 0.09), particularly those patients with LPDs qualifying as ictal-interictal continuum compared with those without ictal-interictal continuum (p = 0.02).

CONCLUSIONS

Lateralized rhythmic delta activity and LPDs are uncommon EEG findings in the pediatric population. Seizures occur commonly in patients with these patterns. Seizures in patients with LPDs, especially those qualifying as ictal-interictal continuum, showed a trend toward being more refractory. Larger studies are needed in the future to further evaluate these findings.

Cortical responses to auditory stimulation predict the prognosis of patients with disorders of consciousness

OBJECTIVE

This study aimed to assess the prognosis of patients with disorders of consciousness (DoC) using auditory stimulation with electroencephalogram (EEG) recordings.

METHODS

We enrolled 72 patients with DoC in the study, which involved subjecting patients to auditory stimulation while EEG responses were recorded. Coma Recovery Scale-Revised (CRS-R) scores and Glasgow Outcome Scale (GOS) were determined for each patient and followed up for three months. A frequency spectrum analysis was performed on the EEG recordings. Finally, the power spectral density (PSD) index was used to predict the prognosis of patients with DoC based on a support vector machine (SVM) model.

RESULTS

Power spectral analyses revealed that the cortical response to auditory stimulation showed a decreasing trend with decreasing consciousness levels. Auditory stimulation-induced changes in absolute PSD at the delta and theta bands were positively correlated with the CRS-R and GOS scores. Furthermore, these cortical responses to auditory stimulation had a good ability to discriminate between good and poor prognoses of patients with DoC.

CONCLUSIONS

Auditory stimulation-induced changes in the PSD were highly predictive of DoC outcomes.

SIGNIFICANCE

Our findings showed that cortical responses to auditory stimulation may be an important electrophysiological indicator of prognosis in patients with DoC.

EEG Correlates of Qualitative Hypermetabolic FDG-PET in Patients With Neurologic Disorders

Background and Objectives

Case reports and case series have described fluorodeoxyglucose (FDG)-PET findings in critically ill patients with rhythmic or periodic EEG patterns, with one reporting that metabolic activity increases with increasing lateralized periodic discharge (LPD) frequency. However, larger studies examining the relationship between FDG-PET hypermetabolism and rhythmic or periodic EEG patterns are lacking. The goal of this study was to investigate the association of FDG-PET hypermetabolism with electroencephalographic features in patients with neurologic disorders.

Methods

This was a single-center, retrospective study of adult patients admitted with acute neurologic symptoms who underwent FDG-PET imaging and EEG monitoring within 24 hours. Subjects were divided into 2 groups based on their FDG-PET metabolism pattern: hypermetabolic activity vs hypometabolic or normal metabolic activity. Chi-square tests and logistic regression were used to determine the relationship of FDG-PET metabolism and EEG findings.

Results

Sixty patients met the inclusion criteria and underwent 63 FDG-PET studies and EEGs. Twenty-seven studies (43%) showed hypermetabolism while 36 studies (57%) showed either hypometabolism or no abnormalities on FDG-PET. Subjects with hypermetabolic FDG-PET were more likely to have electrographic seizures (44% vs 8%, p = 0.001) and LPDs with/without seizures (44% vs 14%, p = 0.007), but not other rhythmic or periodic EEG patterns (lateralized rhythmic delta activity, generalized periodic discharges, or generalized rhythmic delta activity). Subjects with hypermetabolism and LPDs were more likely to have concurrent electrographic seizures (58% vs 0%, p = 0.03), fast activity associated with the discharges (67% vs 0, p = 0.01), or spike morphology (67% vs 0, p = 0.03), compared with subjects with hypometabolic FDG-PET and LPDs.

Discussion

Adults admitted with acute neurologic symptoms who had hypermetabolic FDG-PET were more likely to show electrographic seizures and LPDs, but not other rhythmic or periodic EEG patterns, compared with those with hypometabolic FDG-PET. Subjects with hypermetabolic FDG-PET and LPDs were more likely to have LPDs with concurrent electrographic seizures, LPDs with a spike morphology, and LPDs +F, compared with subjects with hypometabolic FDG-PET.

Continuous Versus Routine Standardized Electroencephalogram for Outcome Prediction in Critically Ill Adults: Analysis From a Randomized Trial

Supplemental Digital Content is available in the text.

To investigate electroencephalogram (EEG) features’ relation with mortality or functional outcome after disorder of consciousness, stratifying patients between continuous EEG and routine EEG.

Recovery from disorders of consciousness: mechanisms, prognosis and emerging therapies

Substantial progress has been made over the past two decades in detecting, predicting and promoting recovery of consciousness in patients with disorders of consciousness (DoC) caused by severe brain injuries. Advanced neuroimaging and electrophysiological techniques have revealed new insights into the biological mechanisms underlying recovery of consciousness and have enabled the identification of preserved brain networks in patients who seem unresponsive, thus raising hope for more accurate diagnosis and prognosis. Emerging evidence suggests that covert consciousness, or cognitive motor dissociation (CMD), is present in up to 15-20% of patients with DoC and that detection of CMD in the intensive care unit can predict functional recovery at 1 year post injury. Although fundamental questions remain about which patients with DoC have the potential for recovery, novel pharmacological and electrophysiological therapies have shown the potential to reactivate injured neural networks and promote re-emergence of consciousness. In this Review, we focus on mechanisms of recovery from DoC in the acute and subacute-to-chronic stages, and we discuss recent progress in detecting and predicting recovery of consciousness. We also describe the developments in pharmacological and electrophysiological therapies that are creating new opportunities to improve the lives of patients with DoC.

Association of Epileptiform Abnormality on Electroencephalography with Development of Epilepsy After Acute Brain Injury

BACKGROUND/OBJECTIVES

Epileptiform abnormalities (EA) on continuous electroencephalography (cEEG) are associated with increased risk of acute seizures; however, data on their association with development of long-term epilepsy are limited. We aimed to investigate the association of EA in patients with acute brain injury (ABI): ischemic or hemorrhagic stroke, traumatic brain injury, encephalitis, or posterior reversible encephalopathy syndrome, and subsequent development of epilepsy.

METHODS

This was a retrospective, single-center study of patients with ABI who had at least 6 hours of cEEG during the index admission between 1/1/2017 and 12/31/2018 and at least 12 months of follow-up. We compared patients with EAs; defined as lateralized periodic discharges (LPDs), lateralized rhythmic delta activity (LRDA), generalized periodic discharges (GPDs), and sporadic interictal epileptiform discharges (sIEDs) to patients without EAs on cEEG. The primary outcome was the new development of epilepsy, defined as the occurrence of spontaneous clinical seizures following hospital discharge. Secondary outcomes included time to development of epilepsy and use of anti-seizure medications (ASMs) at the time of last follow-up visit.

RESULTS

One hundred and one patients with ABI met study inclusion criteria. Thirty-one patients (30.7%) had EAs on cEEG. The median (IQR) time to cEEG was 2 (1-5) days. During a median (IQR) follow-up period of 19.1 (16.2-24.3) months, 25.7% of patients developed epilepsy; the percentage of patients who developed epilepsy was higher in those with EAs compared to those without EAs (41.9% vs. 18.6%, p = 0.025). Patients with EAs were more likely to be continued on ASMs during follow-up compared to patients without EAs (67.7% vs. 38.6%, p = 0.009). Using multivariable Cox regression analysis, after adjusting for age, mental status, electrographic seizures on cEEG, sex, ABI etiology, and ASM treatment on discharge, patients with EAs had a significantly increased risk of developing epilepsy compared to patients without EA (hazard ratio 3.39; 95% CI 1.39-8.26; p = 0.007).

CONCLUSIONS

EAs on cEEG in patients with ABI are associated with a greater than three-fold increased risk of new-onset epilepsy. cEEG findings in ABI may therefore be a useful risk stratification tool for assessing long-term risk of seizures and serve as a biomarker for new-onset epilepsy.

Electroclinical patterns in patients with nonconvulsive status epilepticus: Etiology, treatment, and outcome

INTRODUCTION

This study investigated the clinical and electroencephalography (EEG) features and prognostic factors of patients with nonconvulsive status epilepticus (NCSE).

MATERIALS AND METHODS

We retrospectively reviewed the clinical files and EEG data of 45 (28 females, mean age 54 ± 22.6 years) consecutive patients with NCSE over a five-year period. An EEG interpreter who was blinded to the clinical findings evaluated the EEGs according to the Salzburg Consensus Criteria (SCC) for NCSE. Patient demographics, etiology, neuroimaging and laboratory data, EEG features, treatment, and outcome measures were analyzed.

RESULTS

The most common etiology for NCSE was acute symptomatic etiologies (57.8%) and cerebrovascular disease (48.9%). The majority (68.9%) of the patients presented with new-onset status epilepticus (SE). NCSE was refractory to treatment in 31.1% of patients. The most common status pattern consisted of rhythmic delta/theta activity in 62.3% of EEGs. Twenty-five status patterns on the EEGs were classified as definite, 30 as possible, and six as no NCSE according to the SCC. The in-hospital mortality rate was high (33.3%) showing an association with potentially fatal etiology, refractory SE, treatment with continuous I.V. anesthetics and also the presence of multiple status patterns and nonreactivity in EEGs (p < 0.05).

CONCLUSIONS

The SCC for NCSE have high diagnostic accuracy but do not affect prognosis. Potentially fatal etiology, multiple status patterns on EEG and non-reactive EEGs may carry significantly greater risk for short-term mortality.