Periodic Lateralized Epileptiform Discharges Research Articles

The role of EEG and neuroimaging in the diagnosis of non-convulsive status epilepticus in Subacute Encephalopathy with Seizures in Alcoholics (SESA syndrome): a case report and overview of the literature.

Epileptic seizures are frequently associated with liver dysfunction and alcoholism. Subacute encephalopathy with seizures in chronic alcoholics (SESA) is an underrecognized condition with peculiar clinical, EEG and neuroradiological features.We report the case of a 58-year-old man with previous alcohol use disorder (AUD) and acute-on chronic liver failure on alcohol-related cirrhosis, referred for urgent Orthotopic Liver Transplantation evaluation. The patient presented with delirium, aphasia and progressive deterioration of consciousness leading to intensive care unit admission. EEG showed slow activity with superimposed lateralized periodic discharges (LPDs) over the left temporo-occipital regions and ictal discharges with focal motor phenomena, consistent with focal status epilepticus. Antiseizure treatment with lacosamide and levetiracetam was administered with progressive improvement of consciousness.Brain MRI disclosed T2/FLAIR areas of hyperintensity in the left pulvinar and T2/FLAIR hyperintensity with corresponding DWI hyperintensity in the left hippocampal cortex, suggestive of post/peri-ictal excitotoxic changes with anatomical correspondence to focal LPDs distribution. SWI demonstrated decreased prominence of cortical veins in the left temporo-occipital region consistent with increased venous blood oxygenation in compensatory hyperperfusion.In conclusion, SESA should be suspected in the differential diagnosis of patients with AUD presenting with focal neurological deficits, seizures and focal EEG abnormalities. In this context, EEG and brain MRI represent useful tools with both diagnostic and prognostic value.

Case Report: EEG Picture in a Patient with Post-Stroke Epilepsy

Introduction: Epilepsy is a chronic brain disorder that affects people all over the world. Seizures are the most common neurologic symptom in stroke patients. Approximately 10% of all stroke patients have experienced seizures, and post-stroke seizures generally begin several years after the stroke. Case Illustration: A male patient, 55 years old, Balinese, Kinan, came to the emergency room of Prof. Dr. I.G.N.G. Ngoerah General Hospital with complaints of seizures. The first seizure occurred on December 19, 2021, with a pattern of glancing at the left eye then, followed by full-body twitching, which lasted approximately 5 minutes and stopped on its own. The patient said that before the seizure, the patient was well conscious; during the seizure, the patient was unconscious, and after the seizure, the patient regained consciousness as before the seizure. Then, the seizure repeated the next day (December 20, 2021) with the same pattern and duration, but the patient was not taken for treatment. On physical examination, the patient was alert with vital signs and general physical examination within normal limits. Neurologic examination revealed no focal neurologic deficits. Electroencephalography (EEG) examination showed intermittent slow activity in the left and right fronto-centro-occipital areas. Computed tomography scan (CT-Scan) examination of the head without contrast revealed a hypodense image in the right temporo-parietal lobe. The patient then received anti-epileptic drug (OAE) therapy, OAE therapy given Phenytoin 200 mg every 12 hours intra-orally, Folic Acid 1 mg every 24 hours intra-orally, and anti-platelet and anti-hypertension continued. Discussion: Post-stroke seizure (PSS) is an episode of convulsion that occurs either single or multiple after a stroke, which is thought to be due to irreversible or reversible brain damage. At the same time, post-stroke epilepsy is convulsions after a stroke that occur at least two revivals without provocation with a distance between revivals of more than 24 hours. PSS classification is divided into early post-stroke seizure, where seizures occur onset two weeks early post-stroke, and late (delayed) post-stroke seizure if seizures occur onset after two weeks post-stroke. Post-stroke seizures' most common electroencephalography (EEG) waves are generalized slow waves, focal slowing, focal sharp and slow waves, and periodic lateralized epileptiform discharges (PLEDs). However, 5.1% of patients have normal EEG. The administration of anti-convulsants to prevent recurrent seizures is recommended by the European Guidelines of The European Stroke Organization. In comparison, prophylaxis is not recommended for patients with post-stroke. Keywords: Post-stroke Epilepsy, Stroke, Electroencephalography

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

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). 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. 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). 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.

Neuroimaging correlation with EEG in status epilepticus

PurposeThis study was to correlate EEG patterns with peri-ictal perfusion CT abnormality (PCA) or peri-ictal MR abnormality (PMA) in patients with status epilepticus (SE). MethodsThis is a retrospective study done with SE patients from January 2016 to December 2021. We defined the PCA as single or multi-territorial cortical and/or thalamic hyper-perfusion. The PMA was defined as increased signal intensity in multiple brain regions including the cortex and subcortical regions. EEG patterns were categorized into electrographic seizure (ESz)/electroclinical seizure (ECSz), ictal-interictal continuum (IIC), and lateralized periodic discharges (LPDs) per the American Clinical Neurophysiology Society's guideline. We analyzed the association between the patterns of EEG and the presence of PCA or PMA. ResultsAmong 73 patients, 26% (19/73) showed PCA and 25% (18/73) demonstrated PMA. The patterns of EEG were as follows; ESz/ECSz in 25% (18/73), IIC in 34% (25/73), and LPD in 12% (9/73). There was a significant correlation between the patterns of EEG and the presence of PMA, but not PCA. 48% (12/25) had both PMA and PCA whereas 52% (13/25) showed either PMA (6/25) or PCA (7/25). ConclusionAlthough PCA did not reveal an electro-radiographical correlation, PMA was strongly linked to ESz, ECSz, IIC, and LPD.

Takotsubo cardiomyopathy associated with Herpes simplex encephalitis: A case report and literature review

Takotsubo cardiomyopathy (TCM) is a stress-induced cardiomyopathy characterized by transient left ventricular dysfunction. It can be triggered by various central nervous system pathologies including status epilepticus (SE) and N-methyl-d-aspartate receptor (NMDAr) encephalitis. Herpex simplex encephalitis (HSE) is a life-threatening, sporadic, encephalitis associated with focal or global cerebral dysfunction caused by herpes simplex viruses type 1(HSV-1), or less commonly, type 2(HSV-2). While approximately 20% of patients with HSE develop NMDAr antibodies, not all manifest with encephalitis clinically. We present here a 77-year-old woman admitted with HSV-1 encephalitis who presented with acute encephalopathy and seizure-like activity. Continuous EEG monitoring (cEEG) showed periodic lateralized epileptiform discharges (PLEDs) involving the left parietotemporal region but no evidence of electrographic seizures. Her early hospital course was complicated by TCM which subsequently resolved on repeat TTE. She demonstrated initial neurological improvement. However, five weeks later her mental status declined. Again, no seizures were appreciated on cEEG. Unfortunately, repeat studies including lumbar puncture and magnetic resonance imaging (MRI) of the brain were consistent with NMDAr encephalitis. She was treated with immunosuppression and immunomodulation therapies. To our knowledge we report the first case of TCM secondary to HSE without comorbid status epilepticus. However, further studies are needed to better understand the correlation between, and underlying pathophysiology of HSE and TCM, as well as any potential association with this presentation and subsequent development of NMDAr encephalitis.

Focal nonconvulsive status epilepticus with impaired consciousness in older adults: Prognosis-related variables

ObjectiveTo assess the prognosis-related clinical-EEG characteristics in older adults with focal nonconvulsive status epilepticus with impaired consciousness (focal NCSE). MethodologyWe prospectively assessed clinical variables and EEG data at diagnosis and after an initial pharmacological protocol (within 24 hours) and their relationship with prognosis in older adults with focal NCSE treated at the emergency room. ResultsThe clinical presentation of focal NCSE in 45 adults (mean age 73.5 ± 9.1 years) was characterized by decreased consciousness and the presence of subtle ictal phenomena in 24 cases. On the initial EEG, there were lateralized periodic discharges (LPDs) and lateralized rhythmic delta activity (RDA) in 25 cases and epileptiform discharges (EDs > 2.5 Hz) in 32 cases. After the drug protocol, 33 (73.3%) cases had effective clinical improvement. Death after 30 days occurred in 10 (22.2%) cases. In simple and multiple logistic regression, it was observed that older adults with a history of epilepsy/seizures have a greater chance of clinical improvement. The occurrence of death was associated with the presence of RDA in the initial EEG and its subsequent disappearance (OR 6.93, 95% CI 1.20–46.01, p = 0.033). Higher mortality was associated with the presence of LPDs in the initial EEG and with the presence of LPDs/EDs > 2.5 Hz in the EEG after treatment. ConclusionThe presence of ED > 2.5 Hz in the initial EEG was the most frequent pattern at focal NCSE. Clinical improvement was associated with a history of epilepsy/seizures. Mortality in the focal NCSE was high and was associated with the presence of RDA in the initial EEG and the occurrence of LPDs/ED > 2.5 Hz after treatment.

Teaching Neuro Images : Infantile herpes simplex encephalitis

A 7-month-old girl developed fever, unconsciousness, and left oral clonic seizures. EEG showed background slowing and periodic lateralized epileptiform discharges (PLED) over right central-temporal regions. Brain MRI revealed a right temporal pole T2 hyperintense lesion (figure 1). CSF PCR was positive for herpes simplex virus 1. Five days after starting treatment with acyclovir (45 mg/kg/day) and phenobarbital (7.5 mg/kg/day), the patient was alert and without seizures, and EEG activity improved. Two weeks later, MRI showed a right temporal-polar malacic area (figure 2), and PCR was negative. Although seen in many diseases,1,2 PLED suggest herpes simplex encephalitis in the appropriate clinical context.

Clinical and Electroencephalographic Predictors of Seizures and Status Epilepticus in 12,450 Critically Ill Adults: A Retrospective Cohort Study.

Status epilepticus (SE) is associated with significantly higher morbidity and mortality than isolated seizures. Our objective was to identify clinical diagnoses and rhythmic and periodic electroencephalogram patterns (RPPs) associated with SE and seizures. Retrospective cohort study. Tertiary-care hospitals. Twelve thousand four hundred fifty adult hospitalized patients undergoing continuous electroencephalogram (cEEG) monitoring in selected participating sites in the Critical Care EEG Monitoring Research Consortium database (February 2013 to June 2021). Not applicable. We defined an ordinal outcome in the first 72 hours of cEEG: no seizures, isolated seizures without SE, or SE (with or without isolated seizures). Composite groups included isolated seizures or SE (AnySz) and no seizure or isolated seizures. In this cohort (mean age: 60 ± 17 yr), 1,226 patients (9.8%) had AnySz and 439 patients (3.5%) had SE. In a multivariate model, factors independently associated with SE were cardiac arrest (9.2% with SE; adjusted odds ratio, 8.8 [6.3-12.1]), clinical seizures before cEEG (5.7%; 3.3 [2.5-4.3]), brain neoplasms (3.2%; 1.6 [1.0-2.6]), lateralized periodic discharges (LPDs) (15.4%; 7.3 [5.7-9.4]), brief potentially ictal rhythmic discharges (BIRDs) (22.5%; 3.8 [2.6-5.5]), and generalized periodic discharges (GPDs) (7.2%; 2.4 [1.7-3.3]). All above variables and lateralized rhythmic delta activity (LRDA) were also associated with AnySz. Factors disproportionately increasing odds of SE over isolated seizures were cardiac arrest (7.3 [4.4-12.1]), clinical seizures (1.7 [1.3-2.4]), GPDs (2.3 [1.4-3.5]), and LPDs (1.4 [1.0-1.9]). LRDA had lower odds of SE compared with isolated seizures (0.5 [0.3-0.9]). RPP modifiers did not improve SE prediction beyond RPPs presence/absence ( p = 0.8). Using the largest existing cEEG database, we identified specific predictors of SE (cardiac arrest, clinical seizures prior to cEEG, brain neoplasms, LPDs, GPDs, and BIRDs) and seizures (all previous and LRDA). These findings could be used to tailor cEEG monitoring for critically ill patients.

Rapid response EEG with needle electrodes in an intensive care unit with limited resources

ObjectiveContinuous EEG (cEEG) is the gold standard for detecting seizures and rhythmic and periodic patterns (RPPs) in critically ill patients but is often not available in health systems with limited resources. The current study aims to determine the feasibility and utility of low-cost, practical, limited montage, sub-dermal needle electrode EEG in a setting where otherwise no EEG would be available. MethodsThe study included all adult patients admitted to the intensive care unit of a single center over a 24-month period. Members of the existing ICU care team, mostly nurses, were trained to place 8 sub-dermal needle EEG electrodes to achieve rapid, limited montage-EEG recording. Clinical outcomes were recorded, including any reported major complications; and the EEG findings documented, including background characterization, RPPs, and seizures. ResultsOne hundred twenty-three patients, mean age 68 years, underwent an average of 15.6 min of EEG recording. There were no complications of electrode placement. Overall, 13.0% had seizures (8.1% qualifying as status epilepticus [SE]), 18.7 % had generalized periodic discharges (GPDs), 4.9% had lateralized periodic discharges (LPDs), and 11.4 % sporadic epileptiform discharges (sEDs). Greater mortality was observed in patients with worse background EEGs, seizures, LPDs, or sEDs. ConclusionsRapid, limited montage EEG could be achieved safely and inexpensively in a broad population of critically ill patients following minimal training of existing care teams. SignificanceFor resource poor centers or centers outside of major metropolitan areas who otherwise have no access to EEG, this may prove a useful method for screening for non-convulsive seizures and status epilepticus.

Addition of clobazam successfully treating drug resistant seizures in Heidenhain variant Creutzfeldt Jakob disease: A case report

Creutzfeldt Jakob Disease (CJD) is a rapidly progressive and fatal neurodegenerative disease that is uncommonly accompanied with seizures. In this case report, we describe a 63-year-old male patient who presented with a 3-week history of visual disturbances and clonic movement of his left arm. Additionally, the patient was reported to have developed erratic behaviors along with insomnia during this period. An EEG showed 4 electrographic seizures of bilateral temporo-occipital onset characterized by 1.5Hz periodic discharges, lasting 2-13min. Levetiracetam was started and titrated to the maximal dose however seizures continued so lacosamide and clonazepam were initiated. Despite these aggressive treatments, seizures continued, and oral clobazam 5mg BID replaced clonazepam. Continued electrographic seizures warranted an increase in clobazam to 10mg BID after which the seizures stopped; of note, lateralized periodic discharges (LPDs) remained. The patient's symptoms were consistent with the Heidenhain variant, along with probable CJD due to positive RT-QuIC assay, positive 14-3-3 protein, MRI FLAIR hyperintensities, and EEG findings. Although the patient passed away 3weeks following admission as a result of CJD, we propose that there may be clinical benefit in the use of clobazam in suspected CJD patients presenting with seizures, and its use merits further investigation.

Interrater Reliability of Expert Electroencephalographers Identifying Seizures and Rhythmic and Periodic Patterns in EEGs.

The validity of brain monitoring using electroencephalography (EEG), particularly to guide care in patients with acute or critical illness, requires that experts can reliably identify seizures and other potentially harmful rhythmic and periodic brain activity, collectively referred to as "ictal-interictal-injury continuum" (IIIC). Previous interrater reliability (IRR) studies are limited by small samples and selection bias. This study was conducted to assess the reliability of experts in identifying IIIC. This prospective analysis included 30 experts with subspecialty clinical neurophysiology training from 18 institutions. Experts independently scored varying numbers of ten-second EEG segments as "seizure (SZ)," "lateralized periodic discharges (LPDs)," "generalized periodic discharges (GPDs)," "lateralized rhythmic delta activity (LRDA)," "generalized rhythmic delta activity (GRDA)," or "other." EEGs were performed for clinical indications at Massachusetts General Hospital between 2006 and 2020. Primary outcome measures were pairwise IRR (average percent agreement [PA] between pairs of experts) and majority IRR (average PA with group consensus) for each class and beyond chance agreement (κ). Secondary outcomes were calibration of expert scoring to group consensus, and latent trait analysis to investigate contributions of bias and noise to scoring variability. Among 2,711 EEGs, 49% were from women, and the median (IQR) age was 55 (41) years. In total, experts scored 50,697 EEG segments; the median [range] number scored by each expert was 6,287.5 [1,002, 45,267]. Overall pairwise IRR was moderate (PA 52%, κ 42%), and majority IRR was substantial (PA 65%, κ 61%). Noise-bias analysis demonstrated that a single underlying receiver operating curve can account for most variation in experts' false-positive vs true-positive characteristics (median [range] of variance explained ([Formula: see text]): 95 [93, 98]%) and for most variation in experts' precision vs sensitivity characteristics ([Formula: see text]: 75 [59, 89]%). Thus, variation between experts is mostly attributable not to differences in expertise but rather to variation in decision thresholds. Our results provide precise estimates of expert reliability from a large and diverse sample and a parsimonious theory to explain the origin of disagreements between experts. The results also establish a standard for how well an automated IIIC classifier must perform to match experts. This study provides Class II evidence that an independent expert review reliably identifies ictal-interictal injury continuum patterns on EEG compared with expert consensus.

How to evaluate and assess the epileptogenic/seizure potential of periodic discharges along the ictal-interictal continuum?

AbstractThe ictal–interictal continuum (IIC) is a concept used for those particular EEG patterns that do not meet the strict criteria for status epilepticus but may be associated with neuronal injury. The aim of this article is to review equivocal periodic patterns and to discuss their clinical significance along the IIC. The risk of seizures increases when the frequency of periodic discharges exceeds 2 Hz and when the pattern has features of superimposed rhythmic, sharp, or fast activity (plus modifier). Lateralized periodic discharges (LPDs) are one of the best examples of the IIC. Criteria have been proposed for identifying patterns along the IIC that we called “peri-ictal” LPDs. There is ongoing debate about when to treat patients with these EEG patterns along this spectrum. The term IIC is only an EEG description, and does not in itself reflect a clinical diagnosis, hence management is based on EEG alone. The decision to intensify treatment is based on the combination of EEG, the underlying etiology, the level of consciousness, comorbidities, imaging, and other surrogates of “damage.”

Teaching NeuroImage: Subacute Encephalopathy With Seizures in Alcoholics (SESA)-Related Abnormalities on EEG and MRI.

A 72-year-old woman with alcohol use disorder (last drink 1 week prior) and no seizure history was admitted with encephalopathy. Admission MRI demonstrated focal, edematous T2 FLAIR hyperintensities (Figure 1), and EEG showed abundant lateralized periodic discharges (LPDs) (Figure 2). Evaluation for other etiologies was negative. Treatment with multiple antiseizure medications (ASMs) led to significant clinical and radiographical improvement.

Comparison of Electroencephalography in Patients With Seizures Caused by Neurosyphilis and Viral Encephalitis.

BackgroundNeurosyphilis (NS) lacks specificity in clinical and imaging features, and patients are frequently misdiagnosed as viral encephalitis when they present with seizures. This study aimed to compare electroencephalography (EEG) in patients with seizures resulting from the two diseases and provide guidance for differential diagnosis.MethodsA retrospective study on patients diagnosed with neurosyphilis and viral encephalitis with seizures in the Department of Neurology, Zhongshan Hospital, Xiamen University from 2012 to 2020.ResultsA total of 39 patients with seizures caused by neurosyphilis and 40 patients with seizures caused by viral encephalitis were included. Chi-square test analysis showed that compared with patients with viral encephalitis, patients with neurosyphilis mainly developed in middle-aged and elderly people (p < 0.001), were more likely to have temporal epileptiform discharges (p < 0.001), and less likely to have status epilepticus (SE) (p = 0.029). There was difference between two groups in the EEG performance of lateralized periodic discharges (LPDs) (p = 0.085). The two groups were matched for age and sex by case-control matching, and 25 cases in each group were successfully matched. Patients with neurosyphilis were more likely to have temporal epileptiform discharges than those with viral encephalitis (p = 0.002), and there were no significant differences in LPDs (p = 0.077) and SE (p = 0.088) between two groups.ConclusionWhen EEG shows temporal epileptiform discharges, especially in the form of LPDs, we should consider the possibility of neurosyphilis.

Specific electroencephalogram features in the very early phases of sporadic Creutzfeldt–Jakob disease

Studies on the very early electroencephalography (EEG) features prior to the emergence of generalized periodic discharges (GPDs, generally known as periodic sharp-wave complexes) in Creutzfeldt–Jakob disease (CJD) are rare. Fourteen patients with sporadic CJD (sCJD) (eight with MM1/classic and six with MM2c) were included in this study. The predominant findings of the first EEG were categorized as 1) lateralized periodic discharges (LPDs), 2) central sagittal sporadic epileptiform discharges (CSSEDs) showing midline predominant generalized spike-and-wave complexes and/or sharp waves in the central sagittal regions, or 3) focal epileptiform discharges. Clinical records, magnetic resonance imaging (MRI), and changes in EEG were compared between three groups (LPD in MM1/classic, CSSED in MM1/classic, and focal epileptiform discharge in MM2c). Three (37.5%) and five (62.5%) patients with MM1/classic sCJD were classified into the LPD and CSSED groups, respectively. Patients in the LPD group were accompanied by cortical hyperintensities at the corresponding areas on MRI, while those in the CSSED group showed hyperintensities on MRI at unassociated cortical areas. Follow-up EEG of three (100%) patients in the LPD group and four (80%) in the CSSED group showed transitions to GPDs. All patients with MM1/classic sCJD showed myoclonus on initial EEG, and the symptomatic side was opposite to the hemisphere showing LPDs or higher-amplitude central sagittal epileptiform activity. The periodicity after these EEGs likely contributes to the diagnostic confidence of physicians when patients are in the very early stages of MM1/classic sCJD.

Implications and limitations of magnetic resonance perfusion imaging with 1.5-Tesla pulsed arterial spin labeling in detecting ictal hyperperfusion during non-convulsive status epileptics.

Background: Recent our reports showed that 3-T pseudocontinuous arterial spin labeling (3-T pCASL) magnetic resonance perfusion imaging with dual post labeling delay (PLD) of 1.5 and 2.5 s clearly demonstrated the hemodynamics of ictal hyperperfusion associated with non-convulsive status epilepticus (NCSE). We aimed to examine the utility of 1.5-T pulsed arterial spin labeling (1.5-T PASL), which is more widely available for daily clinical use, for detecting ictal hyperperfusion.Methods: We retrospectively analyzed the findings of 1.5-T PASL with dual PLD of 1.5 s and 2.0 s in six patients and compared the findings with ictal electroencephalographic (EEG) findings.Results: In patients 1 and 2, we observed the repeated occurrence of ictal discharges (RID) on EEG. In patient 1, with PLDs of 1.5 s and 2.0 s, ictal ASL hyperperfusion was observed at the site that matched the RID localization. In patient 2, the RID amplitude was extremely low, with no ictal ASL hyperperfusion. In patient 3 with lateralized periodic discharges (LPD), we observed ictal ASL hyperperfusion at the site of maximal LPD amplitude, which was apparent at a PLD of 2.0 s but not 1.5 sec. Among three patients with rhythmic delta activity (RDA) of frequencies <2.5 Hz (Patients 4–6), we observed obvious and slight increases in ASL signals in patients 4 and 5 with NCSE, respectively. However, there was no apparent change in ASL signals in patient 6 with possible NCSE.Conclusion: The detection of ictal hyperperfusion on 1.5-T PASL might depend on the electrophysiological intensity of the epileptic ictus, which seemed to be more prominent on 1.5-T PASL than on 3-T pCASL. The 1.5-T PASL with dual PLDs showed the hemodynamics of ictal hyperperfusion in patients with RID and LPD. However, it may not be visualized in patients with extremely low amplitude RID or RDA (frequencies <2.5 Hz).

Lateralized Periodic Discharges Detected and Described via Intraoperative Neuromonitoring

ABSTRACT This case report details lateralized periodic discharges (LPDs) detected and described via intraoperative neuromonitoring during tumor resection. Descriptions and quantifications were made according to the American Clinical Neurophysiology Society’s Standardized Critical Care EEG Terminology: 2021 Version. Further, this case illustrates quantitative changes to the LPDs observed in real time as the tumor was removed.

Independent risk factors for seizures in critically ill patients on continuous EEG.

The objective of this study was to characterize the independent risk factors for seizures in critically ill patients monitored with continuous EEG (cEEG). We retrospectively investigated variables associated with cEEG seizures, first in the entire cohort of 156 patients and, subsequently, in the subgroup without seizures in the first 30 minutes of monitoring. Seizures were observed in 19.2% of recordings, and in 50% of these, seizures occurred in the first 30 minutes. In the entire cohort, epilepsy, acute seizures prior to cEEG, interictal epileptiform discharges (IEDs), lateralized periodic discharges (LPDs), and brief potentially ictal rhythmic discharges (BIRDs) were associated with a higher incidence of cEEG seizures, whereas coma, intravenous anaesthetic drugs, and generalized periodic discharges (GPDs) were associated with a lower incidence of seizures. On multivariate analysis, this association was maintained for acute seizures before cEEG (OR: 5.92) and IEDs (OR: 6.81). Excluding patients with seizures at the beginning of monitoring, acute seizures before cEEG, IEDs, LPDs, and BIRDs were associated with an increased risk of seizures. The presence of IEDs or LPDs in the first 30 minutes was associated with a 4.14-fold greater chance of seizures on cEEG. On multivariate analysis, acute seizures prior to recording (OR 7.29) and LPDs (OR: 5.38) remained associated with seizures on cEEG. Due to the sample size, BIRDs were not included in multivariate models. Acute seizures prior to monitoring, IEDs, LPDs and BIRDs are important risk factors for cEEG seizures in critically ill patients.

Associations between Electroencephalographic Variables, Early Post-Traumatic Seizure Risk, and Outcomes following Pediatric Severe Traumatic Brain Injury

AbstractEarly post-traumatic seizures (PTS) are associated with worse outcomes in children with traumatic brain injury (TBI). Our aim was to identify the association between continuous electroencephalogram (cEEG) characteristics and early PTS risk following pediatric severe TBI. We also evaluated the relationship between cEEG background features and outcomes. A single-center retrospective cohort study was performed on children between 0 and 18 years of age admitted to the pediatric intensive care unit from 2016 to 2019 with severe TBI and cEEG monitoring within 7 days of injury. Raw cEEG tracings were reviewed by an epileptologist in accordance with American Clinical Neurophysiology Society (ACNS) Critical Care EEG terminology. Univariate comparisons were made between children with and without early PTS, as well as between those with and without varying cEEG background features. Eighteen children (31%) of the 59 included had early PTS. Interictal abnormalities, inclusive of sporadic spikes and sharp waves, rhythmic delta activity, or lateralized periodic discharges (LPDs) were more common among children with seizures (100 vs. 22%; p &lt; 0.01). LPDs were also more common in the seizure group (44 vs. 2%; p &lt; 0.01). Background discontinuity was associated with worse Glasgow Outcome Scale—Extended Pediatric Version (GOS-E Peds) scores at discharge and 3-, 6-, and 12-month post-discharge (p &lt; 0.01). Lack of reactivity was also associated with worse GOS-E Peds scores at 3-, 6-, and 12-month post-discharge (p &lt; 0.01). Interictal abnormalities and LPDs were each associated with early PTS following pediatric severe TBI. Larger studies should evaluate if high-risk patients would benefit from prolonged cEEG monitoring and/or more aggressive anti-seizure prophylaxis. Discontinuity and lack of variability were associated with worse outcomes. Future studies should attempt to clarify their role as potential early markers of prognosis.

Magnetic resonance imaging findings in focal-onset status epilepticus.

Magnetic resonance imaging (MRI) is commonly used in the diagnostic work-up for status epilepticus (SE). The purpose of this study was to characterize MRI features in SE patients and determine their association with clinical and electroencephalography (EEG) findings. The mid-term consequences of baseline MRI features were also analysed. This is a prospective study including consecutive patients with SE who underwent brain MRI within 240h after SE onset. The MRI protocol included T1-weighted (T1WI), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) sequences. Follow-up MRI was performed after SE resolution in some patients. Sixty patients (56.7% men, mean age 58.3years) were included. SE-related MRI abnormalities were seen in 31 (51.7%), manifesting as hyperintensities on T2W/FLAIR imaging (58.1%) and DWI (74.2%) sequences. Hippocampal and pulvinar involvement was seen in 58.0% and 25.8% of patients, respectively. MRI abnormalities were associated with a longer SE duration (p=0.013) and the presence of lateralized periodic discharges (LPDs) on EEG (p<0.001). Amongst the 33 follow-up MRIs, nine (27.3%) showed mesial temporal sclerosis (MTS), which was associated with severe clinical status (p=0.031), hippocampal oedema (p=0.001) and LPDs (p=0.001) at baseline. A poorer clinical outcome was associated with baseline T2W/FLAIR imaging hyperintensities (p=0.003). MRI showed abnormalities in more than half of SE patients. A longer SE duration and LPDs on EEG were associated with SE-related MRI abnormalities and the development of MTS.