Ictal generalized rhythmic alpha activity during non-convulsive status epilepticus.

Electroencephalographic patterns in unresponsive pediatric patients

Background: In the elderly, nonconvulsive status epilepticus (NCSE) is frequent, however there are still gaps in knowledge about the types of presentation, ictal EEG patterns and prognosis. It is questioned whether the prognosis is related to the etiological factor. Objective: To evaluate the prognosis and clinical-EEG variables in older adults with NCSE according to remote or primary acute etiology. Methods: Clinical-EEG data and the occurrence of death at 30 days in 90 elderly patients diagnosed with NCSE of structural etiology (primary acute or remote) treated at the clinical neurology service of the PUC-Campinas Hospital were evaluated and compared. Results: The mean age was 72.6±8.3 years and 57(63.3%) cases were female, 53(58.9%) cases had acute etiology and 37(41.1%) had remote etiology. The NCSE type was - NCSE-coma in 41(45.6%) cases and NCSE-without coma in 49(54.4%) cases. No significant difference was observed in gender and age according to the type of etiology. There was no difference in the ictal EEG pattern (Salzburg Criterion - A1, A2, A3, A4) according to acute or remote etiology. Death within 30 days occurred in 32(35.6%) cases, with no difference according to etiology. Previous history of seizures/epilepsy occurred more and significantly in older adults with NCSE of remote etiology (Fisher’s exact test, 6(11.3%) vs 17(45.9%), p< 0.000). There was a difference in the type of NCSE according to the etiology, with a higher occurrence of NCSE-coma in cases with acute etiology (chi-square test; 30 vs 11, p=0.012). Conclusion: In the elderly with NCSE, there were differences in the clinical variables according to the acute/remote etiology. Previous history of seizures/epilepsy occurred more frequently in the NCSE of remote etiology, and the clinical presentation of coma was more frequent in the elderly with NCSE of acute etiology. Mortality in this sample was high, with no difference according to acute/remote etiology in elderly patients with NCSE. FAPESP 2023/01226-4.

Abrupt benzodiazepine (BDZ) withdrawal may induce nonconvulsive status epilepticus (NCSE), but information regarding its clinical and EEG features is limited. Our aim was to better characterize this condition. Patients with NCSE according to Salzburg criteria secondary to abrupt BDZ withdrawal identified at our center (2009-2024) were included. Clinical data, seizure semiology, and EEG, were described using ILAE, ACNS, and Salzburg criteria; clinical response to BDZ was quantified using the NCSE response scale (NRS). Recurrences at long-term follow-up were documented. Fifteen patients (median age 68 years, 53% male) were identified, accounting for 4% of all NCSE cases. None had epilepsy, 80% had psychiatric disorders, and 47% had cognitive impairment. Six (40%) subjects were taking only a low-dose BDZ, and only one was above the therapeutic range. Potential seizure facilitators were identified in all but one patient, including withdrawal from other drugs (60%) or infections (33%). There were two clinical presentations: (1) recurrent absence seizures lasting ≤15 min with asymptomatic periods in-between (67%); and (2) continuous, fluctuating consciousness impairment (33%). Motor phenomena (67%) - including increased or decreased blinking, movement-induced myoclonus or automatisms-, and generalized tonic-clonic seizures (60%) were frequent. Before EEG, BDZ withdrawal was not suspected in any case. The ictal EEG activity consisted of generalized, rhythmic, or irregular polyspike-slow waves and spike-slow waves with gradual onset and offset. However, in 20%, this ictal pattern was less developed. Intravenous clonazepam induced an immediate EEG and clinical improvement, but complete control of seizures required 1-3 days. At follow-up, a new abrupt BDZ withdrawal caused absence seizures recurrence in 4/7 patients still on BDZ treatment, but in none of the eight patients who had gradually discontinued BDZ. NCSE secondary to BDZ withdrawal has distinctive clinical and EEG features but is misdiagnosed without an EEG. Reintroduction of BDZ stops seizures, but long-term management requires gradual BDZ discontinuation to prevent recurrences.

De novo aphasic status epilepticus: Finally making the diagnosis by long-term EEG.

Nonconvulsive status epilepticus (ncSE) is a severe condition that may result in neurologic sequelae and epilepsy resistant to pharmacologic treatment. We analyze here seizure and electroencephalography (EEG) patterns and their correlation to the development of a chronic epileptic condition in a guinea pig model of focal ncSE induced by intrahippocampal injection of kainic acid (KA). Electrobehavioral patterns during ncSE induced by unilateral injection of 1μg of KA in the CA1 region of the hippocampus were characterized by continuous video-EEG monitoring in 13 guinea pigs bilaterally implanted with recording electrodes in the hippocampus and neocortex. Video-EEG analysis demonstrates a high variability of seizure type and duration during KA-induced ncSE. Seizures showed focal signs correlated with diverse epileptiform EEG discharge distributions, either diffuse or localized. Nonfocal (bilateral motor) signs during seizures most likely correlated with a diffuse EEG pattern. The evolution into a chronic epileptic condition correlated neither with the severity of seizure pattern nor with the diffusion of the EEG discharges observed during the ncSE. Video-EEG monitoring in a guinea pig model of ncSE induced by unilateral hippocampal injection of KA demonstrates a high variability of electrobehavioral patterns. We demonstrate that the seizure severity score during focal ncSE is not a predictor of the evolution into a chronic epileptic condition of mesial temporal lobe epilepsy.

Objective To explore the clinical features and genetic characteristics of myoclonic-atonic (MAE) caused by gene mutation. Methods The clinical data of a patient with gene mutation from Xiangya Hospital of Central South University was collected. The related literatures were reviewed from Wanfang Data, China National Knowledge Infrastructure, PubMed (until July 2019) by using keywords SLC6A1 and myoclonic-atonic epilepsy . The characteristics of gene mutation and the clinical phenotype of children with myoclonic-atonic were summarized. Results A 8 year and 8 months old girl was enrolled in the study. Her first attack happened at the age of 19 months, and multiple seizure types including myoclonic-atonic, atonic and absence were observed. The seizures were well controlled by valproate (VPA), but she has mild-moderate intellectual disability. Whole exome-sequencing study identified a de novo nonsense variant of c. 46G>T(p.Glu16*)in gene. A total of 27 cases including the present case with gene mutation were analyzed. 22 mutations were identified, including 11 missense mutations, 5 nonsense mutations, 3 frameshift mutations, 2 splicing mutation and 1 with chromosome microdeletion. Among them 26 patients had more one type of seizures, 20 cases had absence seizures, 17 cases had atonic seizures, 14 cases had myoclonic seizures, 11 cases had myoclonic-atonic seizures, 4 cases had generalized tonic-clonic seizures, 3 cases had eyelid myoclonias, 2 cases had nonconvulsive status epilepticus and 2 cases had tonic seizure. 24 patients had described intelligence assessment. Among them, 18 had developmental delay before onset, 11 had developmental regression after onset. There were 9 cases with autistic features, 4 cases with attention deficit hyperactivity disorder and 3 cases with ataxia. The seizures of 17 cases were controlled, 4 cases had partial seizure control, 3 cases had no significant improvement, and other 3 cases were unclear. Conclusions The main clinical feature of MAE patients with gene mutations is absence and atonic seizures, cognition before onset can be impaired, and some patients had behavioral problems, such as autistic features or attention deficit hyperactivity disorders. VPA is recommend as first-line treatment. Key words: Epilepsies, myoclonic; Epilepsy, absence; Glucose transporter type 1; Mutation; Child

A recent assessment of the classification of nonconvulsive status epilepticus (NCSE) has incorporated the specific electroencephalographic (EEG) patterns on a syndromic basis. Such a clinical EEG syndromic approach may enable more accurate and expedited diagnosis of particular subtypes of NCSE so as to improve therapy. Herein, we review the characteristics of subacute encephalopathy with seizures in alcoholics syndrome, a subtype of focal NCSE occurring in chronic alcoholism with specific features, including encephalopathy, lateralized periodic discharges on the EEG, chronic microvascular ischemia on neuroimaging studies, and possible recurrence when chronic antiseizure treatment is stopped.

Prognostic value of the second ictal intracranial pattern for the outcome of epilepsy surgery

IntroductionStatus Epilepticus is defined as a condition that can have long-term outcomes involving neuronal death and injury due to the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms that lead to abnormally prolonged seizures. Electroconvulsive therapy (ECT) is a highly effective treatment option for psychiatric disorders. Although it rarely occurs in the treatment, non-convulsive status epilepticus can be seen as a complication after ECT. Due to its rarity, this complication is not yet well understood, is challenging to diagnose, and information about treatment options is limited.ObjectivesBy sharing this case report, we aim to emphasize the importance of being careful in terms of the risk of status epilepticus in patients receiving electroconvulsive therapy.MethodsHere in we present a 29-year-old patient with no previous neurological disease and who had a history of schizophrenia. Electroconvulsive therapy was planned because the patient was resistant to antipsychotic treatment. EEG was planned for the patient who had urinary incontinence during the ninth session of ECT. Generalized slow wave activity and intermittent rhythmic delta activity were observed in the EEG, therefore it was found suspicious for NCSE, and the patient was planned to perform an EEG again by administering diazepam to confirm the diagnosis. After diazepam, the patient whose EEG tracing was clearly improved was admitted to the neurology intensive care unit. He was followed up for 48 hours with continuous 4 mg/hour/day midazolam and continuous bedside EEG in the neurology intensive care unit. Concomitant lamotrigine was started at 100 mg/day. Significant improvement in EEG, sinusoidal alpha, and beta waves with the eye open was observed at the 48th hour, and the patient was transferred back to the psychiatry service. Lamotrigine treatment was increased up to 200 mg/day and clozapine treatment was adjusted to 350 mg/day in the psychiatry service. In the patient whose EEG was requested again before discharge.ResultsThe diagnosis of NCSE post-ECT can be laborious; the symptoms may not be characteristic and clear, and usually not distinguish from symptoms of confusion, delirium, or psychiatric illness, hence the follow-up psychiatrist should be careful. In suspicious cases, EEG should be taken, especially in patients at risk for seizures. These risky conditions include previous seizure history, and lithium or clozapine use.ConclusionsThe diagnosis of NCSE after ECT is a demanding condition. Particular attention should be paid to factors that will lower the seizure threshold. In cases with ECT treatment with clozapine, intermittent clozapine blood levels can be quantified and medication interactions and smoking can be considered. When the cases are examined, the common aspect of most of them is that the treatments have good results.Disclosure of InterestNone Declared

PII: S1525-5050(08)00088-7

Carbamazepine (CBZ) is effective in treating KCNQ2/3-related seizures, which may present with a distinctive amplitude-integrated electroencephalography (aEEG) pattern. To assess how improved recognition of the distinctive aEEG ictal pattern associated with KCNQ2/3 variants has enabled early and effective targeted therapy with CBZ. Retrospective descriptive study of five neonates with KCNQ2/3 pathogenic gene variants admitted at a level 3 neonatal intensive care unit (NICU) over an 8-year period. The distinctive ictal aEEG pattern was recognized in four neonates after an average of 61.5 hours (minimum 12 hours, maximum 120 hours) from the first electroclinical seizure and prompted the use of CBZ that was effective in all. The two most recently diagnosed patients could avoid polytherapy as they received CBZ as the first and second antiseizure medication, respectively. Three out of five patients with continuous normal voltage (CNV), sleep-wake cycling (SWC), and shorter postictal suppression had normal neurodevelopmental outcome. Regarding the remaining two infants, one was not trialed with CBZ and had a high seizure burden, both presented with a prolonged postictal suppression, no SWC, and had moderate-to-severe developmental delay. Genetic results became available after the neonatal period in all but one of the infants, who had a prenatal diagnosis. Recognition of the distinctive ictal aEEG pattern in the NICU allowed early and effective targeted therapy with CBZ in four neonates, well before genetic results became available. Furthermore, a CNV background pattern with SWC and short postictal suppression were associated with normal developmental outcomes.

Background: Acute encephalopathy is a common neurological manifestation in coronavirus disease 2019 (COVID-19) patients and presents with confusion, delirium, or poor responsiveness. Non-convulsive status epilepticus (NCSE) is an important differential diagnosis in this situation. The electroencephalography (EEG) patterns in COVID-19 patients remain largely unknown. Method: A literature search was conducted on MEDLINE, EMBASE, and Cochrane database. Eligibility criteria included case series and case reports of COVID-19 patients with neurological complication who underwent EEG. Two authors screened all resulting studies and extracted the data independently. Results: Four retrospective case control studies and eleven case reports were identified. Background diffuse slow activity were seen in most of the COVID-19 patients. Other EEG patterns reported included status epilepticus, focal slow activity, rhythmic periodic discharges, and interictal epileptiform discharges. Imaging and CSF studies were available in only a few patients. Conclusions: Acute encephalopathy is common in the context of COVID-19. There is no specific EEG pattern found in these patients. Keywords: COVID-19, coronavirus, SAR-CoV-2, electroencephalogram, EEG

Utility of CT perfusion in seizures and rhythmic and periodic patterns

Epilepsy with myoclonic-atonic seizures, also known as Doose syndrome or myoclonic–astatic epilepsy (MAE), represents a challenging pediatric epilepsy syndrome, initially described by Doose et al. in 1970. MAE accounts for 1%–2.2% of juvenile-onset epilepsy cases, characterized by normal early development, followed by seizure onset between 7 months and 6 years. Seizure types include myoclonic, myoclonic-atonic, generalized tonic–clonic, and atypical absences, often accompanied by nonconvulsive status epilepticus. Electroencephalogram typically shows parietal-dominant rhythmic theta activity or a posterior 4 Hz pattern. While conventional antiseizure medications (ASMs) offer some efficacy, outcomes vary widely, and up to 50% of patients may experience refractory seizures and poor intellectual outcomes. The ketogenic diet (KD), a high-fat, low-carbohydrate diet inducing ketosis, has shown promise in reducing seizure frequency and severity in refractory epilepsy, including MAE. This case report describes a successful outcome with a South Indian style KD in a 3-year-old boy with Doose syndrome presenting with 20–25 daily head drop seizures despite multiple ASMs and steroid therapy. Initiation of a home-based KD utilizing traditional household ingredients significantly reduced seizure frequency by 60% within 1 month and 80% within 2 months and was 100% seizure-free in 3rd month following KD, alongside developmental improvements. The KD was well-tolerated, with improved nutritional status. This case underscores KD’s potential as a viable complementary therapy for MAE, emphasizing the need for ongoing parental support and supervision to ensure dietary adherence and optimize outcomes. It is commonly believed that the KD is challenging for the South Indian population to follow due to the high carbohydrate content in South Indian cuisine. However, this case demonstrates that a KD can indeed be tailored around South Indian dishes, highlighting the uniqueness of this approach. When the diet is customized to consider a child’s dietary habits, culture, and cuisine, it becomes easier to follow over the long term, leading to effective seizure control. Further research is necessary to refine dietary protocols and evaluate long-term efficacy in MAE management.

Neuroinvasive West Nile virus (WNV) is rare, occurring in less than 1% of those infected, and may manifest as meningitis, encephalitis, and/or acute flaccid paralysis. Patients may present initially with nonspecific symptoms including fevers. Although rare, neuroinvasive WNV is associated with significant morbidity and mortality. The mainstay of treatment is supportive care. Electroencephalography (EEG) allows for identification of nonconvulsive status epilepticus and other epileptiform and nonepileptiform patterns suggestive of underlying cognitive dysfunction. Our aim was to describe specific EEG patterns observed in WNV neuroinvasive disease. A retrospective chart review was conducted. West Nile virus was confirmed with serum and/or cerebrospinal fluid markers. Patients with a history of abnormal EEG were excluded. Electroencephalography reports were classified into categories based on the presence of epileptiform activity, focal slowing, generalized periodic discharges with triphasic morphology, and frontally predominant generalized rhythmic delta activity. In our cohort of 34 patients, 60% of focal EEG abnormalities were anterior-predominant, seen as epileptiform discharges, focal slowing, or frontally predominant generalized rhythmic delta activity. Nonepileptiform EEG patterns included nonspecific slowing and generalized periodic discharges with triphasic morphology. Two patients had electrographic seizures, one arising from the frontocentral head region. EEGs are important in the evaluation of WNV infection to rule out seizures or alternative causes of encephalopathy, and because of the risk of nonconvulsive seizures or status epilepticus in encephalitis. Although an anterior predominance of EEG abnormalities was seen in our cohort, this most likely is more correlative to encephalopathy than WNV itself. Although a specific correlative EEG pattern may not accompany all cases of WNV neuroinvasive disease, WNV should be considered as a possible etiology in patients presenting with an encephalitic or meningitic syndrome in the presence of abnormal EEG findings including encephalopathic patterns, particularly those with anterior predominant EEG changes.