Efficacy and tolerability of levetiracetam in people with and without intellectual disabilities: A naturalistic case control study.

INTRODUCTION: People with Intellectual Disabilities (PwID) are twenty times more likely than general population to have epilepsy. Guidance for prescribing antiseizure medication (ASM) to PwID is driven by trials excluding them. Levetiracetam (LEV) is a first-line ASM in the UK. Concerns exist regarding LEV's behavioural and psychological adverse effects, particularly in PwID. There is no high-quality evidence comparing effectiveness and adverse effects in PwID to those without, prescribed LEV. METHODS: Pooled casenote data for patients prescribed LEV (2000-2020) at 18 UK NHS Trusts were analysed. Demographics, starting and maximum dose, adverse effects, dropouts and seizure frequency between ID (mild vs. moderate-profound (M/P)) and general population for a 12-month period were compared. Descriptive analysis, Mann-Whitney, Fisher's exact and logistic regression methods were employed. RESULTS: 173 PwID (mild 53 M/P 120) were compared to 200 without ID. Mean start and maximum dose were similar across all groups. PwID (Mild & M/P) were less likely to withdraw from treatment (P = 0.036). No difference was found between ID and non-ID or between ID groups (Mild vs M/P) in LEV's efficacy i.e. >50 % seizure reduction. Significant association emerged between ID severity and psychiatric adverse effects (P = 0.035). More irritability (14.2 %) and aggression (10.8 %) were reported in M/P PwID. CONCLUSION: PwID and epilepsy have high rates of premature mortality, comorbidities, treatment resistance and polypharmacy but remain poorly researched for ASM use. This is the largest studied cohort of PwID trialled on LEV compared to general population controls. Findings support prescribing of LEV for PwID as a first-line ASM.

Early and established status epilepticus: The impact of timing of intervention, treatment escalation and dosing on outcome.

OBJECTIVE: We investigated the management and outcome of early and established status epilepticus including timing, dosing and selection of benzodiazepines along with the timing and efficacy of second line treatments. METHODS: Retrospective single tertiary centre observational cohort study to identify all cases of SE between January 2019 and February 2022. RESULTS: 252 cases were identified. Seizures terminated spontaneously in 136 (54%) cases. 116 (46%) were given benzodiazepines, of which 29 (25%) were given at least one benzodiazepine by family/carers, and 72 (62.1%) received benzodiazepines by ambulance services. Benzodiazepines terminated seizures in 83 (71.6%) cases. The commonest benzodiazepine used was buccal midazolam (35.5%). Median time to first benzodiazepine was 14.5 (6-27) minutes. There was a positive correlation between time to first benzodiazepine and time to seizure cessation, progression to second- and third-line treatment, and respiratory complications (p<0.05). 73 (62.9%) cases received a correct benzodiazepine dose. Benzodiazepine underdosing was associated with longer seizure duration (p<0.05). 33 (28.4%) cases progressed to second-line treatment where mean time to treatment was 59.4 min (±32.3 min). The commonest second-line treatment was Levetiracetam (53.8%), followed by Phenytoin (43.6%) with SE termination in 57.5% cases. 14 (12.1%) cases progressed to third-line treatment; mean time to treatment was 60.6 min (±22.24 min). Respiratory complications occurred in 17 (6.75%) cases; none due to benzodiazepines. There were two deaths in refractory SE. CONCLUSION: Early administration of benzodiazepines and optimal dosing is associated with a higher rate of SE termination. Levetiracetam was the most commonly used second line treatment.

The etiology and mortality of new-onset refractory status epilepticus (NORSE) in adults: A systematic review and meta-analysis.

New-onset refractory status epilepticus (NORSE) is a devastating neurological presentation. There is a paucity of large studies on NORSE as it is a relatively new clinical syndrome. The aim of this review was to summarize the etiologies and establish a mortality rate for NORSE. Two independent authors systematically searched the following electronic databases from January 1, 2005 April 20, 2021: PubMed, Embase, OVID, Scopus, Web of Science, "Clinicaltrials.gov," and the International Standard Randomised Controlled Trial Number (ISRCTN) registry. We included all primary research studies of NORSE in adults and excluded commentaries, reviews, pre-clinical studies, and pediatric populations. Etiology was extracted from all studies meeting eligibility criteria, whereas data relating to treatments, hospital stay, functional outcomes, and mortality were extracted from studies with sample size ≥5. We conducted a random-effects meta-analysis of mortality rate with meta-regression testing for significant covariates. Of 1482 studies, 109 case reports and case series met our criteria, comprising 395 cases of NORSE. The most common etiology was cryptogenic in 197 cases (49.9%), followed by autoimmune in 143 cases (36.2%). The pooled mortality rate was 22% (95% confidence interval 17%-27%; N studies  = 15), with low heterogeneity ( I 2  = 0%). Meta-regression revealed that year of study, treatment with ketogenic diet or immunotherapy, percentage of cryptogenic cases, and length of intensive care unit stay were not significant covariates for mortality. Common treatments included antiseizure medications (median 5), general anesthesia, and immunotherapy such as corticosteroids, intravenous immunoglobulin, and plasma exchange. Mean length of intensive care admission was 33.4 days, with 52% of cases diagnosed with epilepsy on discharge. Neurocognitive impairment was a common sequela of NORSE. NORSE is associated with a high mortality. Half of cases remain cryptogenic, which presents a diagnostic challenge. Future focus should be on elucidating the underlying neurobiology and determining the most effective therapeutic interventions.

Has the mortality of status epilepticus changed over the past few decades?

Earlier and more aggressive treatment of status epilepticus has long been established orthodoxy. In addition to increasing therapeutic options, it is of critical importance to understand whether or not this has translated into improved prognosis. In this review, we examine the evidence as to whether the mortality of convulsive status epilepticus changed over the past few decades. In particular, we discuss a recent systematic review and meta-analysis examining this question and its implications. We discuss potential reasons why there is no evidence of improved prognosis in terms of mortality and ways in which this may be addressed. Finally, we advocate the urgent need for accurate data on functional outcomes in non-fatal cases of status epilepticus. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Retention of brivaracetam in adults with drug-resistant epilepsy at a single tertiary care center.

INTRODUCTION: Brivaracetam (BRV) is licensed as an adjunctive treatment for focal epilepsy. We describe our clinical experience with BRV at a large UK tertiary center. METHODS: Adults initiated on BRV between July 2015 and July 2020 were followed up until they discontinued BRV or September 2021. Data on epilepsy syndrome, duration, seizure types, concomitant and previous antiseizure medication (ASM) use, BRV dosing, efficacy, and side effects were recorded. Efficacy was categorized as temporary (minimum three months) or ongoing (at last follow-up) seizure freedom, ≥50% seizure reduction, or other benefits (e.g., no convulsions or daytime seizures). Brivaracetam retention was estimated using Kaplan-Meier survival analysis. RESULTS: Two-hundred people were treated with BRV, of whom 81% had focal epilepsy. The mean (interquartile range [IQR]) follow-up time was 707 (688) days, and the dose range was 50-600 mg daily. The mean (IQR) of the previous number of used ASMs was 6.9 (6.0), and concomitant use was 2.2 (1.0). One-hundred and eighty-eight people (94%) had previously discontinued levetiracetam (LEV), mainly due to side effects. 13/200 (6.5%) were seizure free for a minimum of six months during treatment, and 46/200 (23%) had a ≥50% reduction in seizure frequency for six months or more. Retention rates were 83% at six months, 71% at 12 months, and 57% at 36 months. Brivaracetam was mostly discontinued due to side effects (38/75, 51%) or lack of efficacy (28/75, 37%). Concomitant use of carbamazepine significantly increased the hazard ratio of discontinuing BRV due to side effects (p = 0.006). The most commonly reported side effects were low mood (20.5%), fatigue (18%) and aggressive behavior (8.5%). These side effects were less prevalent than when the same individuals took LEV (low mood, 59%; aggressive behavior, 43%). Intellectual disability was a risk factor for behavioral side effects (p = 0.004), and a pre-existing mood disorder significantly increased the likelihood of further episodes of low mood (p = 0.019). CONCLUSIONS: Brivaracetam was effective at a broad range of doses in managing drug-resistant epilepsy across various phenotypes, but less effective than LEV in those who switched due to poor tolerability on LEV. There were no new tolerability issues, but 77% of the individuals experiencing side effects on BRV also experienced similar side effects on LEV.

New-Onset Refractory Status Epilepticus (NORSE): The Queen Square Neuro-ICU experience.

The introduction and widespread adoption of the term 'NORSE' - new-onset refractory status epilepticus - raises both fundamental conceptual and pragmatic questions. We studied a cohort of patients with 'NORSE' at the National Hospital for Neurology and Neurosurgery to investigate the clinical features, treatment responses, and outcomes with a focus on sub-group analysis. We identified 26 cases of 'NORSE'. There was no difference in prognosis between 'NORSE' and non-'NORSE' RSE, nor in any sub-analysis in the 'NORSE' cohort. We discuss the utility and validity of the term NORSE as a descriptor for a subgroup with RSE in whom the underlying etiologies are heterogeneous and pathophysiological mechanisms are unknown.

New-onset seizures in older people: Clinical features, course and outcomes.

OBJECTIVE: The incidence of epilepsy increases with age. With current demographic trends, this presents a healthcare challenge. We investigated the clinical spectrum of first seizures, evaluated neuroimaging and EEG findings, and determined clinical outcomes, including anti-seizure medication (ASM) response in older people. In addition, we sought to understand the relative effects of age and frailty on ASM response. METHODS: A retrospective single centre cohort study of 207 cases ≥60 years' old, 113 of whom were eventually diagnosed with a first seizure in a specialist epilepsy clinic. RESULTS: 65/113 (57.5%) presented with either focal aware or focal impaired awareness seizures. Stroke was the most common aetiological association (31.9%, 36/113), and odds of seizure recurrence did not significantly differ between aetiologies. 55/86 (64.0%) who started an ASM had no seizure recurrence. 14/48 (29.2%) who underwent EEG had epileptiform abnormalities, however EEG result directly affected management in only 4/48 (8.3%). The most common MRI findings were small vessel disease (37/93, 39.8%), stroke (27/93, 29.0%) and global atrophy (14/93, 15.1%). Increasing age and frailty did not affect the odds of seizure recurrence or of experiencing ASM side effects. Severity of small vessel disease or atrophy did not affect odds of seizure recurrence. CONCLUSION: Our data inform the management of first seizures in older people and provisionally support the use of ASMs in patients with increasing age and frailty, despite concerns over polypharmacy and comorbidity. Our findings should be replicated in larger cohorts.

Advances in the management of generalized convulsive status epilepticus: what have we learned?

Convulsive status epilepticus is the most serious manifestation of an epileptic diathesis. In the early stages (5-30 min), there exists class A evidence to support the efficacy of benzodiazepines as first-line treatment. As status epilepticus progresses into the later stages, the evidence for treatment becomes less robust until we are depending upon short case series and case reports for the treatment of refractory status epilepticus. However, the past year saw the publication of three randomized controlled trials in the setting of benzodiazepine-resistant established convulsive status epilepticus: the EcLiPSE and ConSEPT studies, compared levetiracetam to phenytoin in children; and the ESETT study compared fosphenytoin, levetiracetam and sodium valproate in adults and children. In addition, the emergence of data from the SENSE study, a multicentre multinational prospective cohort study and the publication of a systematic review and meta-analysis of the mortality of status epilepticus over the past 30 years, has brought the treatment of status epilepticus into sharp focus. In this update we provide a detailed analysis of these studies and their impact on clinical practice. We review contentious areas of management in status epilepticus where a consensus is lacking and advance the case for more research on existing and alternative treatment strategies.

A retrospective cohort study of super-refractory status epilepticus in a tertiary neuro-ICU setting.

PURPOSE: Over the last decade, the range of treatments available for the management of super-refractory status epilepticus (SRSE) has expanded. However, it is unclear whether this has had an impact on its high mortality and morbidity. The aim of this study was to investigate whether there has been a change in the outcome of SRSE over time in a neurological intensive care unit (ICU) within a tertiary centre. METHODS: Analysis of a retrospective cohort of 53 admissions from 45 patients to the neurological ICU at the National Hospital for Neurology and Neurosurgery, Queen Square, London, between January 2004 and September 2018. RESULTS: Significant reductions were observed in both duration of SRSE over time and in the time spent in ICU, suggesting that treatment quality has improved over time. A median of four antiseizure drugs (ASDs) were given prior to seizure resolution. In 23 % resolution of SRSE occurred following optimisation of current treatment rather than introduction of a new ASD. The mortality rate was very low at 11 % by 6 months; however, there was no indication of improvement in outcome as all surviving patients had a modified Rankin scale score of 3-5 upon discharge from ICU, classified as moderate-to-severe disability. CONCLUSION: Neither the survival rate nor the outcome score changed significantly over time, suggesting that changes in the treatment of SRSE have had no impact on patient outcome.

Epidemiological and cohort study finds no association between COVID-19 and Guillain-Barré syndrome.

Reports of Guillain-Barré syndrome (GBS) have emerged during the Coronavirus disease 2019 (COVID-19) pandemic. This epidemiological and cohort study sought to investigate any causative association between COVID-19 infection and GBS. The epidemiology of GBS cases reported to the UK National Immunoglobulin Database was studied from 2016 to 2019 and compared to cases reported during the COVID-19 pandemic. Data were stratified by hospital trust and region, with numbers of reported cases per month. UK population data for COVID-19 infection were collated from UK public health bodies. In parallel, but separately, members of the British Peripheral Nerve Society prospectively reported incident cases of GBS during the pandemic at their hospitals to a central register. The clinical features, investigation findings and outcomes of COVID-19 (definite or probable) and non-COVID-19 associated GBS cases in this cohort were compared. The incidence of GBS treated in UK hospitals from 2016 to 2019 was 1.65-1.88 per 100 000 individuals per year. GBS incidence fell between March and May 2020 compared to the same months of 2016-19. GBS and COVID-19 incidences during the pandemic also varied between regions and did not correlate with one another (r = 0.06, 95% confidence interval: -0.56 to 0.63, P = 0.86). In the independent cohort study, 47 GBS cases were reported (COVID-19 status: 13 definite, 12 probable, 22 non-COVID-19). There were no significant differences in the pattern of weakness, time to nadir, neurophysiology, CSF findings or outcome between these groups. Intubation was more frequent in the COVID-19 affected cohort (7/13, 54% versus 5/22, 23% in COVID-19-negative) attributed to COVID-19 pulmonary involvement. Although it is not possible to entirely rule out the possibility of a link, this study finds no epidemiological or phenotypic clues of SARS-CoV-2 being causative of GBS. GBS incidence has fallen during the pandemic, which may be the influence of lockdown measures reducing transmission of GBS inducing pathogens such as Campylobacter jejuni and respiratory viruses.

Eslicarbazepine acetate response in intellectual disability population versus general population.

BACKGROUND: A quarter of people with intellectual disability (ID) have epilepsy, compared to approximately one in a hundred across the general population. Evidence for the safe and effective prescribing of antiepileptic drugs (AEDs) for those with ID is, however, limited. AIMS OF STUDY: This study seeks to strengthen the research evidence around Eslicarbazepine Acetate (ESL), a new AED, by comparing response of individuals with ID to those from the general population who do not have ID. METHODS: A single data set was created through retrospective data collection from English and Welsh NHS Trusts. The UK-based Epilepsy Database Research Register (Ep-ID) data collection and analysis method were used. RESULTS: Data were collected for 93 people (36 ID and 57 'no ID'). Seizure improvement of '>50%' was higher at 12 months for 'no ID' participants (56%), compared to ID participants (35%). Retention rates were slightly higher for those with ID (56% compared to 53%). Neither difference was significant. CONCLUSIONS: Tolerance and Efficacy for ID and 'no ID' people in our data set were similar. Seizure improvement and retention rates were slightly lower than that found in other European data sets, but findings strengthen the evidence for the use of ESL in the ID population.

Lacosamide in the general population and in people with intellectual disability: Similar responses?

PURPOSE: Epilepsy prevalence is significantly higher in people with Intellectual Disability (ID) compared to people with epilepsy (PWE) from the general population. Increased psychological and behavioural problems, healthcare costs, morbidity, mortality and treatment resistance to antiepileptic drugs (AEDs) is associated with epilepsy in ID populations. Prescribing AEDs for PWE and ID is challenging and influenced heavily by studies conducted with the general population. Our study compares Lacosamide (LCM) response for the ID population to those from the general population; using data from an UK based epilepsy database register (EP ID/PDD AED Register). METHODS: Pooled retrospective case notes data for PWE prescribed LCM at 11 UK NHS Trusts were analysed. Participants were classified as per WHO guidance into groups of moderate-profound ID, mild ID and General population. Demographics, concomitant AEDs, starting and maximum dosage, exposure length, adverse effects, dropout rates, seizure frequency were collected. Group differences were reported as odds ratios estimated from univariable logistic regression models. RESULTS: Of 232 consented participants, 156 were from the general population and 76 had ID (24 mild, 52 moderate-profound). Twelve month withdrawal rates and reasons, efficacy, side-effects, start and maximum doses were similar between the groups. Dose titration between baseline and three months was significantly slower in the ID group (p = 0.02). CONCLUSION: There were no differences for LCM outcomes between general and ID groups. Slower LCM titration in ID populations in the first 3 months was associated with higher retention and lower behavioural side effects as compared to similar European studies.

A Clinical, Neuropathological and Genetic Study of Homozygous A467T POLG-Related Mitochondrial Disease.

Mutations in the nuclear gene POLG (encoding the catalytic subunit of DNA polymerase gamma) are an important cause of mitochondrial disease. The most common POLG mutation, A467T, appears to exhibit considerable phenotypic heterogeneity. The mechanism by which this single genetic defect results in such clinical diversity remains unclear. In this study we evaluate the clinical, neuropathological and mitochondrial genetic features of four unrelated patients with homozygous A467T mutations. One patient presented with the severe and lethal Alpers-Huttenlocher syndrome, which was confirmed on neuropathology, and was found to have a depletion of mitochondrial DNA (mtDNA). Of the remaining three patients, one presented with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), one with a phenotype in the Myoclonic Epilepsy, Myopathy and Sensory Ataxia (MEMSA) spectrum and one with Sensory Ataxic Neuropathy, Dysarthria and Ophthalmoplegia (SANDO). All three had secondary accumulation of multiple mtDNA deletions. Complete sequence analysis of muscle mtDNA using the MitoChip resequencing chip in all four cases demonstrated significant variation in mtDNA, including a pathogenic MT-ND5 mutation in one patient. These data highlight the variable and overlapping clinical and neuropathological phenotypes and downstream molecular defects caused by the A467T mutation, which may result from factors such as the mtDNA genetic background, nuclear genetic modifiers and environmental stressors.

The Role of Calcium Channels in Epilepsy.

A central theme in the quest to unravel the genetic basis of epilepsy has been the effort to elucidate the roles played by inherited defects in ion channels. The ubiquitous expression of voltage-gated calcium channels (VGCCs) throughout the central nervous system (CNS), along with their involvement in fundamental processes, such as neuronal excitability and synaptic transmission, has made them attractive candidates. Recent insights provided by the identification of mutations in the P/Q-type calcium channel in humans and rodents with epilepsy and the finding of thalamic T-type calcium channel dysfunction in the absence of seizures have raised expectations of a causal role of calcium channels in the polygenic inheritance of idiopathic epilepsy. In this review, we consider how genetic variation in neuronal VGCCs may influence the development of epilepsy.

Postictal generalized EEG suppression and SUDEP: a review.

SUMMARY: Sudden unexpected death in epilepsy (SUDEP) remains a leading cause of epilepsy-related death, and yet, its pathogenic mechanisms remain ill-defined. Although epidemiological studies of SUDEP in heterogenous populations have established a number of clinical associations, evaluation and stratification of individual risk remains difficult. Thus, potential markers as predictors of risk of SUDEP are important not only clinically but also for research on SUDEP prevention. Recordings from rare monitored cases of SUDEP demonstrate postictal generalized EEG suppression after terminal seizures, raising expectations that postictal generalized EEG suppression may identify individuals at higher risk. In this review, we consider the literature on postictal generalized EEG suppression and evaluate its relevance and utility as a possible marker of SUDEP.