A hybrid 1D CNN-BiLSTM model for epileptic seizure detection using multichannel EEG feature fusion.

Epilepsy, a chronic non-communicable disease is characterized by repeated unprovoked seizures, which are transient episodes of abnormal electrical activity in the brain. While Electroencephalography (EEG) is considered as the gold standard for diagnosis in current clinical practice, manual inspection of EEG is time consuming and biased. This paper presents a novel hybrid 1D CNN-Bi LSTM feature fusion model for automatically detecting seizures. The proposed model leverages spatial features extracted by one dimensional convolutional neural network and temporal features extracted by bi directional long short-term memory network. Ictal and inter ictal data is first acquired from the long multichannel EEG record. The acquired data is segmented and labelled using small fixed windows. Signal features are then extracted from the segments concurrently by the parallel combination of CNN and Bi-LSTM. The spatial and temporal features thus captured are then fused to enhance classification accuracy of model. The approach is validated using benchmark CHB-MIT dataset and 5-fold cross validation which resulted in an average accuracy of 95.90%, with precision 94.78%, F1 score 95.95%. Notably model achieved average sensitivity of 97.18% with false positivity rate at 0.05/hr. The significantly lower false positivity and false negativity rates indicate that the proposed model is a promising tool for detecting seizures in epilepsy patients. The employed parallel path network benefits from memory function of Bi-LSTM and strong feature extraction capabilities of CNN. Moreover, eliminating the need for any domain transformation or additional preprocessing steps, model effectively reduces complexity and enhances efficiency, making it suitable for use by clinicians during the epilepsy diagnostic process.

Genetic variant interpretation for the neurologist - A pragmatic approach in the next-generation sequencing era in childhood epilepsy.

Genetic advances over the past decade have enhanced our understanding of the genetic landscape of childhood epilepsy. However a major challenge for clinicians ha been understanding the rationale and systematic approach towards interpretation of the clinical significance of variant(s) detected in their patients. As the clinical paradigm evolves from gene panels to whole exome or whole genome testing including rapid genome sequencing, the number of patients tested and variants identified per patient will only increase. Each step in the process of variant interpretation has limitations and there is no single criterion which enables the clinician to draw reliable conclusions on a causal relationship between the variant and disease without robust clinical phenotyping. Although many automated online analysis software tools are available, these carry a risk of misinterpretation. This guideline provides a pragmatic, real-world approach to variant interpretation for the child neurologist. The focus will be on ascertaining aspects such as variant frequency, subtype, inheritance pattern, structural and functional consequence with regard to genotype-phenotype correlations, while refraining from mere interpretation of the classification provided in a genetic test report. It will not replace the expert advice of colleagues in clinical genetics, however as genomic investigations become a first-line test for epilepsy, it is vital that neurologists and epileptologists are equipped to navigate this landscape.

Metabolic causes of pediatric developmental & epileptic encephalopathies (DEE)- genetic variant analysis in a south Indian cohort.

PURPOSE: Drug-resistant epilepsy is seen in patients with inborn errors of metabolism and metabolic dysfunction in neurons is crucial to brain disorders associated with psychomotor impairment. Diagnostic rates of metabolic causes of developmental and epileptic encephalopathy (DEE) using next generation sequencing have been rarely studied in literature. METHODS: A prospective hospital study was carried out in 384 children with DEE, who underwent genetic testing. Metabolic disorders were evaluated with biochemical blood/urine assays and when required CSF estimations performed. RESULTS: A total of 154 pathogenic/likely pathogenic variants in 384 children were identified. Out of 384 children, 89 were clinically suspected to have probable or possible metabolic disorders. Pathogenic/likely pathogenic variants in metabolic genes were identified in 39 out of 89 (43.8 %) and promising VUS in 28 (31.4 %). These included variants for progressive myoclonus epilepsies (21; 53.8 %), DEE with focal/multifocal seizures (8; 20.5 %), generalized epilepsy (5;12.8 %), early myoclonic encephalopathy (2; 5.1 %), LGS (1; 2.6 %) and West syndrome (2; 5.1 %). CONCLUSION: Our cohort demonstrates for the first time from the Indian subcontinent that identification of metabolic variants can guide investigations and has therapeutic implications in patients with variable DEE phenotypes. A high utility is noted with regard to diagnosis and prognostication, given the low yield of available biochemical tests, indicating cost-effectiveness of this approach.

Impact of variant subtype on electro-clinical phenotype of Dravet syndrome- a South Indian cohort study.

OBJECTIVE: We aimed to compare the electroclinical correlates of truncating and missense variants of SCN1A variants in children with Dravet syndrome (DS) and to determine phenotypic features in relation to variants identified and seizure outcomes. METHODS: A single center prospective study was carried out on a South Indian cohort. Patients below 18 years of age who met the clinical criteria for DS who had undergone genetic testing and completed a minimum of one year follow up were included. We compared the differences in clinical profile, seizure outcome, developmental characteristics and anti-seizure medication (ASM) responsiveness profiles between patients with missense and truncating variants. RESULTS: Out of a total of 3967 children with drug-resistant epilepsy during the period 2015-2021, 49 patients who fulfilled the inclusion criteria were studied. Thirty-seven had positive genetic tests, out of which 29 were SCN1A variants and 9 were other novel variants. The proportion of missense (14; 48.3%) and truncating SCN1A variants (15; 51.7%) was similar. A significant trend for developing multiple seizure types was noted among children with truncating variants (p = 0.035) and seizure freedom was more likely among children with missense variants (p = 0.042). All patients with truncating variants had ASM resistant epilepsy (p = 0.020). Developmental outcomes did not differ between the variant subtypes. CONCLUSION: Our results show that children harbouring missense variants demonstrated a significantly lower propensity for multiple seizure subtypes and a higher proportion with seizure freedom. However developmental implications appear to be independent of variant subtype.

Is intraoperative electrocorticography (ECoG) for long-term epilepsy-associated tumors (LEATs) more useful in children?-A Randomized Controlled Trial.

OBJECTIVES: The utility of intraoperative electrocorticography (ECoG)-guided resective surgery for pediatric long-term epilepsy-associated tumors (LEATs) with antiseizure medication (ASM) resistant epilepsy is not supported by robust evidence. As epilepsy networks and their ramifications are different in children from those in adults, the impact of intraoperative ECoG-based tailored resections in predicting prognosis and influencing outcomes may also differ. We evaluated this hypothesis by comparing the outcomes of resections with and without the use of ECoG in children and adults by a randomized study. METHODS: From June 2020 to January 2022, 42 patients (17 children and 25 adults) with LEATs and antiseizure medication (ASM)-resistant epilepsy were randomly assigned to one of the 2 groups (ECoG or no ECoG), prior to surgical resection. The 'no ECoG' arm underwent gross total lesion resection (GTR) without ECoG guidance and the ECoG arm underwent GTR with ECoG guidance and further additional tailored resections, as necessary. Factors evaluated were tumor location, size, lateralization, seizure duration, preoperative antiepileptic drug therapy, pre- and postresection ECoG patterns and tumor histology. Postoperative Engel score and adverse event rates were compared in the pediatric and adult groups of both arms. Eloquent cortex lesions and re-explorations were excluded to avoid confounders. RESULTS: Forty-two patients were included in the study of which 17 patients were in the pediatric cohort (age < 18 years) and 25 in the adult cohort. The mean age in the pediatric group was 11.11 years (SD 4.72) and in the adult group was 29.56 years (SD 9.29). The mean duration of epilepsy was 9.7 years (SD 4.8) in the pediatric group and 10.96 (SD 8.8) in the adult group. The ECoG arm of LEAT resections had 23 patients (9 children and 14 adults) and the non-ECoG arm had 19 patients (8 children and 11 adults). Three children and 3 adults from the ECoG group further underwent ECoG-guided tailored resections (average 1.33 additional tailored resections/per patient.).The histology of the tailored resection specimen was unremarkable in 3/6 (50%).Overall, the commonest histology in both groups was ganglioglioma and the temporal lobe, the commonest site of the lesion. 88.23% of pediatric cases (n = 15/17) had an excellent outcome (Engel Ia) following resection, compared to 84% of adult cases (n = 21/25) at a mean duration of follow-up of 25.76 months in children and 26.72 months in adults (p = 0.405).There was no significant difference in seizure outcomes between the ECoG and no ECoG groups both in children and adults, respectively (p > 0.05). Additional tailored resection did not offer any seizure outcome benefit when compared to the non-tailored resections. CONCLUSIONS: The use of intraoperative electrocorticography in LEATs did not contribute to postoperative seizure outcome benefit in children and adults. No additional advantage or utility was offered by ECoG in children when compared to its use in adults. ECoG-guided additional tailored resections did not offer any additional seizure outcome benefit both in children and adults.

SREDA: An Uncommon and Misleading EEG Rhythm.

Subclinical Rhythmic Electroencephalographic Discharges of Adults (SREDA) is a benign EEG variant characterized by sharply contoured rhythmic theta activity occurring bilaterally with maximum activity over the parietal or the posterior head region. These paroxysms are not associated with any objective or subjective clinical manifestations. SREDA, the rarest and last reported benign EEG pattern with no known clinical significance yet, is detailed in this case report. We provide the case of a gentleman with epilepsy who underwent vEEG recording in our lab. The described case is interesting due to its EEG characteristics as well as its clinical picture, which misled us for at least a while. It provides an illustration of how over interpretation of normal EEG patterns may result in an incorrect diagnosis.

Arginase deficiency-An unheralded cause of developmental epileptic encephalopathy.

Arginase deficiency, which leads to hyperargininaemia is a rare urea cycle disorder caused by a mutation in the ARG1 gene. It is an under-recognized cause of pediatric developmental epileptic encephalopathy, with the key coexistent clinical features being developmental delay or regression and spasticity. Detection of ARG1 gene mutation on genetic testing is the confirmatory diagnostic test. However, elevated levels of plasma arginine and low plasma arginase level can be considered as biochemical markers for diagnosis. We present two cases of arginase deficiency with genetically confirmed ARG1 mutation in one and biochemical confirmation in both. As the spectrum of epilepsy in arginase deficiency has been less explored, we attempted to elucidate the novel electroclinical features and syndromic presentations in these patients. Informed consent was obtained from families of patients. Electroclinical diagnosis was consistent with Lennox Gastaut syndrome (LGS) in the first patient while the second patient had refractory atonic seizures with electrophysiological features consistent with developmental and epileptic encephalopathy. Though primary hyperammonaemia is not a consistent feature, secondary hyperammonaemia in the setting of infectious triggers and drugs like valproate (valproate sensitivity) has been well described as also observed in our patient. In the absence of an overt antecedent in a child with spasticity and seizure disorder, with a progressive course consistent with a developmental epileptic encephalopathy, arginase deficiency merits consideration. Diagnosis often has important therapeutic implications with respect to dietary management and choice of the appropriate antiseizure medications.

Satisfaction among persons with epilepsy towards physical consultation versus online video consultation for follow-up.

PURPOSE: Telemedicine gained popularity in the setting of the COVID-19 pandemic. We aimed to study the satisfaction levels of persons with epilepsy (PWE) with online video consultation (OVC) and physical consultation (PC). METHODS: This was a cross-sectional questionnaire-based study conducted in a tertiary referral care center for epilepsy in India. All PWE who had availed of both OVC and PC were included. Those who did not give consent to a questionnaire were excluded. A questionnaire was given to assess patients' satisfaction regarding OVC and PC. Scores for each question for both OVC and PC were compared. RESULTS: One hundred and forty-one patients who had PC earlier and later availed of OVC from December 2020 to July 2021 formed the cohort. Seventy one patients who responded to the questionnaire were included. 49% and 51% of the patients belonged to urban and rural regions respectively. 8.5% of the patients were off anti-seizure medications (ASM), while 5.6% and 85.9% were on single and multiple ASMs respectively. There were no differences between PC and OVC regarding ease of getting the appointment, privacy during a consultation, patients' perceived chances of missing consultations, and overall comfort and experience on either type of consultation. Physical consultation scored more than OVC in patients' satisfaction with the time doctor spent with them, an opportunity to communicate their queries well, clarifications received from the doctor, and the likelihood of patients recommending the particular type of consultation to others(p < 0.05). CONCLUSIONS: Online video consultation can be a satisfactory alternative to PC and can improve patient satisfaction if some of the issues in OVC are addressed properly.

Individualised prediction of drug resistance and seizure recurrence after medication withdrawal in people with juvenile myoclonic epilepsy: A systematic review and individual participant data meta-analysis.

Background: A third of people with juvenile myoclonic epilepsy (JME) are drug-resistant. Three-quarters have a seizure relapse when attempting to withdraw anti-seizure medication (ASM) after achieving seizure-freedom. It is currently impossible to predict who is likely to become drug-resistant and safely withdraw treatment. We aimed to identify predictors of drug resistance and seizure recurrence to allow for individualised prediction of treatment outcomes in people with JME. Methods: We performed an individual participant data (IPD) meta-analysis based on a systematic search in EMBASE and PubMed - last updated on March 11, 2021 - including prospective and retrospective observational studies reporting on treatment outcomes of people diagnosed with JME and available seizure outcome data after a minimum one-year follow-up. We invited authors to share standardised IPD to identify predictors of drug resistance using multivariable logistic regression. We excluded pseudo-resistant individuals. A subset who attempted to withdraw ASM was included in a multivariable proportional hazards analysis on seizure recurrence after ASM withdrawal. The study was registered at the Open Science Framework (OSF; https://osf.io/b9zjc/). Findings: Our search yielded 1641 articles; 53 were eligible, of which the authors of 24 studies agreed to collaborate by sharing IPD. Using data from 2518 people with JME, we found nine independent predictors of drug resistance: three seizure types, psychiatric comorbidities, catamenial epilepsy, epileptiform focality, ethnicity, history of CAE, family history of epilepsy, status epilepticus, and febrile seizures. Internal-external cross-validation of our multivariable model showed an area under the receiver operating characteristic curve of 0·70 (95%CI 0·68-0·72). Recurrence of seizures after ASM withdrawal (n = 368) was predicted by an earlier age at the start of withdrawal, shorter seizure-free interval and more currently used ASMs, resulting in an average internal-external cross-validation concordance-statistic of 0·70 (95%CI 0·68-0·73). Interpretation: We were able to predict and validate clinically relevant personalised treatment outcomes for people with JME. Individualised predictions are accessible as nomograms and web-based tools. Funding: MING fonds.

C12orf57 pathogenic variants: a unique cause of developmental encephalopathy in a south Indian child.

Open reading frame variants which lack stop codons such as C12orf57 variants are known to cause Temtamy syndrome, an extremely rare disorder characterized by intellectual disability, seizures, facial dysmorphism and agenesis of corpus callosum. C12orf57 was initially reported to be required for human corpus callosum development. We report the first child who is of Indian origin with developmental and epileptic encephalopathy (DEE) with a unique phenotypic evolution as focal onset reflex seizures. We performed whole exome sequencing of genomic DNA isolated from peripheral blood samples of proband and his parents. Two pathogenic compound heterozygous variants, a start loss variant (Chr12:7053285:c.1A>G) and a premature stop gain variant (Chr12:7053327:c.43C>T), involving the C12orf57 gene were identified in the proband. Our case report which details genotyping in this rare syndromic developmental encephalopathy, with no prior cases reported from India, expands the ethnic spectrum of patients.

Does Etiology and Hypsarrhythmia Subtype Influence Outcome in West Syndrome? Challenges Encountered from a Referral Center Perspective.

Background: Prediction of outcome of West syndrome (WS) in relation to etiology and electrophysiology remain pertinent challenges. Objective: This study aimed to compare electro-clinical and imaging characteristics between WS of "unknown-etiology"; "symptomatic"WS; to gauge the evolution and impact of electroencephalographic (EEG) patterns on seizure outcomes. Materials and Methods: Electro-clinico-radiological data of 76 children with WS who were followed up for atleast 1 year was collected for reviewing clinical, therapeutic and EEG profiles (sub-typed as typical and modified hypsarrhythmia [HA]). Quantified seizure scores were assessed. Results: Among 76 children included in this retrospective analysis, 31 (40.8%) were of unknown-etiology and 45 (59.2%) were "symptomatic" (structural cause/developmental-encephalopathy). Children with symptomatic WS (p = 0.037), specifically with gliosis on imaging (p = 0.05) and typical HA (including the multifocal subtype; P = 0.023) were more likely to have other seizure types before onset of spasms and exhibit prior delay or regression in milestones (p = 0.017). There was negative correlation between time to diagnosis and reduction in seizure scores (r = -0.32; p = 0.005).Significant reduction was noted in seizure scores with pharmacotherapy, irrespective of etiology (P < 0.001 in unknown-etiology and symptomatic subgroups). Seizure freedom rates did not differ between typical and modified HA groups (p = 0.215) with a higher proportion of children with meaningful reduction in seizure scores in the former sub-group (p = 0.030). Children who failed to achieve seizure remission were more likely to exhibit developmental impairment (p = 0.019). Conclusions: Early diagnosis and initiation of optimal therapy is crucial towards improving outcome, irrespective of etiology (which impacts pre-spasm development) and HA subtypes.

Utility of 18F-fluorodeoxyglucose positron emission tomography in presurgical evaluation of patients with epilepsy: A multicenter study.

OBJECTIVE: 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) is widely used in presurgical assessment in patients with drug-resistant focal epilepsy (DRE) if magnetic resonance imaging (MRI) and scalp electroencephalography (EEG) do not localize the seizure onset zone or are discordant. METHODS: In this multicenter, retrospective observational cohort study, we included consecutive patients with DRE who had undergone FDG-PET as part of their presurgical workup. We assessed the utility of FDG-PET, which was defined as contributing to the decision-making process to refer for resection or intracranial EEG (iEEG) or to conclude surgery was not feasible. RESULTS: We included 951 patients in this study; 479 had temporal lobe epilepsy (TLE), 219 extratemporal epilepsy (ETLE), and 253 epilepsy of uncertain lobar origin. FDG-PET showed a distinct hypometabolism in 62% and was concordant with ictal EEG in 74% in TLE and in 56% in ETLE (p < .001). FDG-PET was useful in presurgical decision-making in 396 patients (47%) and most beneficial in TLE compared to ETLE (58% vs. 44%, p = .001). Overall, FDG-PET contributed to recommending resection in 78 cases (20%) and iEEG in 187 cases (47%); in 131 patients (33%), FDG-PET resulted in a conclusion that resection was not feasible. In TLE, seizure-freedom 1 year after surgery did not differ significantly (p = .48) between patients with negative MRI and EEG-PET concordance (n = 30, 65%) and those with positive MRI and concordant EEG (n = 46, 68%). In ETLE, half of patients with negative MRI and EEG-PET concordance and three quarters with positive MRI and concordant EEG were seizure-free postsurgery (n = 5 vs. n = 6, p = .28). SIGNIFICANCE: This is the largest reported cohort of patients with DRE who received presurgical FDG-PET, showing that FDG-PET is a useful diagnostic tool. MRI-negative and MRI-positive cases with concordant FDG-PET results (with either EEG or MRI) had a comparable outcome after surgery. These findings confirm the significance of FDG-PET in presurgical epilepsy diagnostics.

Exploring Novel Word Learning Via Fast Mapping and Explicit Encoding in Persons with Temporal Lobe Epilepsy.

Objective: To explore novel word learning via fast mapping (FM) and explicit encoding (EE) in temporal lobe epilepsy (TLE). Methods: 16 right and 16 left temporal lobe epilepsy (RTLE and LTLE) patients along with 32 normal controls (NC) underwent learning of 24 novel object name pairs through standard FM and EE techniques. Their learning was assessed via a three-choice alternate delayed recognition task on the day of learning and on the following day. Recognition scores were compared using nonparametric statistics across the groups with P value set at <.05. Results: RTLE and NC performed similarly, while LTLE and NC differed significantly in novel word learning irrespective of the method of encoding. LTLE and RTLE differed in EE-based novel word learning alone. Further, with respect to encoding techniques, all groups performed better on EE compared to FM. The novel word associations learned via FM showed a lesser decline compared to EE following overnight integration in RTLE and NC. Conclusion: Novel word learning via FM did not facilitate learning above EE in TLE patients or NC. But FM-based words could better overcome forgetting following overnight integration in RTLE and NC. Hence, it is possible that FM has the potential to improve retention of novel information following overnight integration in RTLE as in NC. However, its efficacy in improving retention in LTLE needs further evidence.

Do Spike Domain Analysis Interictally Correlate With the Ictal Patterns in Temporal Lobe Epilepsy?

PURPOSE: To study if one can conceptualize the scalp ictal onset pattern through analysis of interictal spike domain analysis in temporal lobe epilepsy (TLE). METHODS: Seventy-four patients with unilateral mesial temporal sclerosis (MTS) were categorized into "type A" interictal epileptiform discharges (IEDs) with negativity over infero-lateral scalp electrodes over temporal region and contralateral central region showing positivity; all IEDs other than type A were categorized as type B. The ictal electrographic patterns was termed "focal" when confined to side of MTS, was "regional" when lateralized to the ipsilateral hemisphere; "diffuse" if nonlateralized/localized; and ictal onset contralateral to MTS termed as "discordant." RESULTS: A total of 377 seizures and 5,476 spikes were studied. These were divided into four types: (1) type A IEDs ipsilateral to MTS (44 patients), (2) type A IEDs bitemporally (16 patients), (3) type A IEDs contralaterally (7 patients) and type B IEDs ipsilaterally, and (4) bilateral type B IEDs (7 patients). The ictal pattern was either focal or regional in 51 of 60 patients (85%) with type A IEDs; it was "diffuse" in 9 patients (15%). Diffuse ictal onset was seen in 12 of 14 (86%) with either ipsilateral/bitemporal type B IEDs. Ictal onset on the opposite hemisphere was noted in 2 (14%). CONCLUSIONS: Type A IEDs signify a focal ictal onset and type B IEDs suggest a diffuse ictal onset in patients with MTS on one side. SIGNIFICANCE: Interictal spike domain analysis helps predicting ictal patterns in temporal lobe epilepsy.

How does "locus of control" affect persons with epilepsy?

PURPOSE: Locus of control (LOC) is the degree to which people believe that they have control over the outcome of events in their lives. A person's locus can be internal, external, or chance. A person with internal locus of control believes that one can control one's own life. A person with external locus of control believes that his life is controlled by external factors or people over which he has no influence. A person with chance locus of control believes that fate, chance, or luck controls his own life. The aim of the current study was to determine the health locus of control, anxiety, and depression levels in persons with epilepsy (PWE) and to assess whether locus of control has relation to anxiety, depression, and seizure control. METHODS: Patients aged 18 years or older with a history of epilepsy for at least 1 year were recruited from the outpatient epilepsy clinic or from the inpatient epilepsy monitoring unit at SCTIMST, Trivandrum from January 2019 to May 2020. Patients filled the questionnaire form consisting of demographic data, age of onset of seizures, present seizure control, and the current antiepileptic drugs. The Hospital Anxiety and Depression (HAD) scale was used to estimate the level of anxiety and depression in these patients. The Form-C of the Multidimensional Health Locus of Control (MHLC) scale was used to evaluate the health locus of control. Healthy controls aged 18 years or older and free of any chronic disease or psychiatric illness were also recruited. They were asked to fill the questionnaire forms with basic demographic data. HAD scale was used to estimate the level of anxiety and depression and form-C of MHLC was used to evaluate the health locus of control in the healthy controls. The mean scores of anxiety, depression, and locus of control were compared between the two groups. RESULTS: A total of 170 participants were recruited which consisted of 100 PWE and 70 healthy controls. The mean anxiety and depression scores were 8.13(SD = 4.23) and 5.85(SD = 3.66) in the PWE group and 6.75(SD = 3.39) and 4.14(SD = 2.96) in the control group, respectively. The mean internal, external, and chance LOC scores were 24.95(SD = 10.92), 26.94(SD = 4.96), and 24.41(SD = 6.46) in the PWE group; and 29.44(SD = 5.62), 26.53(SD = 5.79), and 19.9(SD = 7.13) in the control group, respectively. Persons with epilepsy had higher chance LOC scores and lower internal LOC scores compared to controls (p = 0.00003, p < 0.00001 respectively). There were no differences in the external LOC scores between the two groups (p = 0.620). Persons with epilepsy with some level of anxiety had lower internal LOC scores compared to patients with no anxiety (p = 0.04). PWE with poor seizure control had higher external LOC score and lower internal LOC scores which however did not reach statistical significance. Persons with epilepsy with poor seizure control had higher anxiety and depression scores. CONCLUSIONS: Persons with epilepsy had low perceptions of internal and strong perceptions of chance health locus of control. This means that PWE feel that luck plays an important role in their disease control. This information is important in the counseling of persons with epilepsy.

Can occurrence of convulsive status epilepticus during video telemetry be predicted? Observations from an epilepsy monitoring unit.

PURPOSE: The objective of the study was to evaluate the frequency, clinical, and video-electroencephalographic (VEEG) predictors of convlusive status epilepticus (CSE) in the epilepsy-monitoring unit (EMU). METHODS: The data of all patients who had CSE in our EMU between 2008 and 2017 were reviewed. For each case, two age- and diagnosis-matched subjects who underwent VEEG and did not develop CSE were taken as internal controls. Electro-clinical data of both the groups were compared. Predictors of CSE were assessed using logistic regression analysis. RESULTS: Out of 11,188 video-telemetries were conducted between 2008-17, forty-three events of CSE (0.38%) were recorded. On comparisons with 86 internal controls no differences were apparent on prevalence of cognitive impairment, structural lesion, number of baseline anti-seizure medications (ASM), ASM taper schedule, ictal patterns, and duration of VEEG monitoring. Inter-ictal rhythmic periodic patterns had significantly higher prevalence in cases (p = 0.028). Logistic regression analysis revealed that odds of CSE were higher with past history of SE [p = 0.008; adjusted odds ratio (OR) = 5.48 (confidence intervals {CI} 1.55-19.28)] and in presence of rhythmic spike and wave discharges [p = 0.016, OR = 33.518(CI = 1.93-581.4)]; the odds were lower if the first two seizures recorded did not evolve into CSE [p = 0.009, OR = 0.247 (CI = 0.08-0.70)] and if there was prior history of daily seizures [p = 0.02, OR = 0.250 (CI = 0.07-0.84)]. CONCLUSION: CSE is a rare yet important adverse event in EMU. Clinical predictors are more relevant in comparison to EEG variables. Extent of ASM withdrawal may not directly account for occurrence of CSE; factors inherent to a patient's epilepsy are deterministic.

Unmasking the entity of 'drug-resistant' perioral myoclonia with absences: the twitches, darts and domes!

Perioral myoclonia with absences (POMA) is not recognized as a unique electro-clinical syndrome and studies suggest its inclusion under the genetic generalized epilepsy (GGE) spectrum. The aim of this study was to explore the prevalence and electro-clinical homogeneity of this disorder in an epilepsy monitoring unit. Between 2013 and 2019, among drug-resistant epilepsy patients who were referred for video-telemetry, those diagnosed with POMA based on the presence of documented absences with prominently observed peri-oral muscular contractions accompanied by generalized EEG features were included. Among 62 patients who were diagnosed with absence epilepsy, five finally met the criteria for POMA (8.1%) with late childhood or adolescent onset of epilepsy. Four (80%) had a referral diagnosis of focal epilepsy based on historical focal features with exacerbation of seizures on oxcarbazepine. All five patients demonstrated brief absences with orbicularis oris muscle contractions accompanied by subtle focal phenomenology. One patient had concurrent axial-appendicular myoclonic jerks precipitated by hyperventilation. While four patients had strikingly identical interictal and ictal characteristics of typical absence epilepsy, one patient demonstrated additional atypical generalized polyspike discharges without a "dart-dome" morphology. Therapeutic response to introduction of sodium valproate was noted in all five patients. Features that were not consistent with the diagnosis were apparent in one patient who was re-classified with combined focal and generalized epilepsy. Differentiating aspects in this patient included multifocal discharges, background slowing, fast-recruiting ictal rhythms and valproate resistance. This is one of the largest case series of POMA. This entity, which falls under the spectrum of GGE, remains under-diagnosed and its distinctive electro-clinical features need to be recorded in order to prevent misclassification as focal epilepsy of probable opercular origin. Background-slowing, atypical ictal rhythms and valproate unresponsiveness are not consistent with the diagnosis of this unique absence epilepsy. [Published with video sequences].