The diagnostic test accuracy of a screening questionnaire and algorithm in the identification of adults with epilepsy

Antiseizure Medications and Cardiovascular Events in Older People With Epilepsy

Importance

How epilepsy may promote cardiovascular disease remains poorly understood.

Objective

To estimate the odds of new-onset cardiovascular events (CVEs) over 6 years in older people with vs without epilepsy, exploring how enzyme-inducing antiseizure medications (EIASMs) and traditional cardiovascular risk factors mediate these odds.

Design, Setting, and Participants

This was a prospective cohort study using the comprehensive cohort of the Canadian Longitudinal Study on Aging (CLSA), with 6 years of follow-up (2015-2021, analysis performed in December 2023). The CLSA is an ongoing, national study of 51 338 adults aged 45 to 85 years at baseline who are recruited in Canada. The comprehensive cohort includes 30 097 individuals living near 1 of 11 data collection centers. Participation in the CLSA was voluntary; participation rate was 45%. Among those in the comprehensive cohort, individuals reporting no previous history of CVEs (ie, stroke, transient ischemic attack [TIA], or myocardial infarction [MI]) at baseline were excluded. No other exclusion criteria were applied. A total of 86% of participants completed follow-up.

Exposure

Lifetime history of epilepsy.

Main Outcomes and Measures

The primary outcome was new-onset CVEs over 6 years. Secondary outcomes were new-onset strokes, TIAs, and MIs. Logistic models were fitted for these outcomes as a function of epilepsy, age, sex, household income, and education level. Mediation analyses were conducted for strong EIASM use, weak EIASM use, Framingham score, Physical Activity Scale for the Elderly (PASE) score, and waist to hip ratio.

Results

Among the 30 097 individuals in the comprehensive cohort, a total of 27 230 individuals (mean [SD] age, 62.3 [10.1] years; 14 268 female [52.4%]) were included, 431 with a lifetime history of epilepsy. New-onset CVEs were more likely in epilepsy, with an adjusted odds ratio of 2.20 (95% CI, 1.48-3.27). The proportion of the effect of epilepsy on new-onset CVEs was mediated as follows by each of the following variables: strong EIASM use, 24.6% (95% CI, 6.5%-54.6%), weak EIASM use, 4.0% (95% CI, 0.8%-11.0%), Framingham score, 1.4% (95% CI, -1.6% to 4.5%), PASE score, 3.3% (95% CI, 1.4%-6.8%), and waist to hip ratio, 1.6% (95% CI, 0.4%-3.7%).

Conclusions and Relevance

Results of this cohort study reveal that epilepsy was associated with new-onset CVEs. Nearly one-third of this association can be explained by EIASMs. These findings should be considered when choosing an antiseizure medication for a person at risk for cardiovascular disease.

Role and mechanism of EphB3 in epileptic seizures and epileptogenesis through Kalirin

BACKGROUND

The EphB receptor tyrosine kinase family participates in intricate signaling pathways that orchestrate neural networks, guide neuronal axon development, and modulate synaptic plasticity through interactions with surface-bound ephrinB ligands. Additionally, Kalirin, a Rho guanine nucleotide exchange factor, is notably expressed in the postsynaptic membrane of excitatory neurons and plays a role in synaptic morphogenesis. This study postulates that Kalirin may act as a downstream effector of EphB3 in epilepsy. This investigation focuses on understanding the link between EphB3 and epilepsy.

MATERIALS AND METHODS

Chronic seizure models using LiCl-pilocarpine (LiCl/Pilo) and pentylenetetrazol were developed in rats. Neuronal excitability was gauged through whole-cell patch clamp recordings on rat hippocampal slices. Real-time PCR determined Kalirin's mRNA expression, and Western blotting was employed to quantify EphB3 and Kalirin protein levels. Moreover, dendritic spine density in epileptic rats was evaluated using Golgi staining.

RESULTS

Modulation of EphB3 functionality influenced acute seizure severity, latency duration, and frequency of spontaneous recurrent seizures. Golgi staining disclosed an EphB3-driven alteration in dendritic spine density within the hippocampus of epileptic rats, underscoring its pivotal role in the reconfiguration of hippocampal neural circuits. Furthermore, our data propose Kalirin as a prospective downstream mediator of the EphB3 receptor.

CONCLUSIONS

Our findings elucidate that EphB3 impacts the action potential dynamics in isolated rat hippocampal slices and alters dendritic spine density in the inner molecular layer of epileptic rat hippocampi, likely through Kalirin-mediated pathways. This hints at EphB3's significant role in shaping excitatory circuit loops and recurrent seizure activity via Kalirin.

Risk of Post-stroke Epilepsy Following Stroke-Associated Acute Symptomatic Seizures

Objective: Post-stroke epilepsy (PSE) is associated with increased morbidity and mortality. Stroke-associated acute symptomatic seizures are an important risk factor: 20.8–34.3% of these patients will go on to develop PSE. Identifying these “high risk” individuals may result in earlier PSE diagnosis, treatment, and avoidance of seizure-related morbidity. This study was to identify predictors of PSE development in patients with stroke-associated acute symptomatic seizures.

Participants and Methods: This was a retrospective cohort study of 167 patients with stroke-associated acute symptomatic seizures admitted to the Neurology Department of a tertiary Hospital of China, from 1 May 2006 to 30 January 2020. Both those with primary ischemic stroke and intracerebral hemorrhage were included in the study. Patient demographics, medical history, stroke-associated, and seizure-related variables were evaluated with univariable analysis and multivariable Cox regression analysis. PSE was defined as unprovoked seizures occurring > 7 days post-stroke. Data points were extracted from medical records and supplemented by tele-interview.

Results: Of the 167 patients with stroke-associated acute symptomatic seizures, 49 (29.3%) developed PSE. NIHSS score > 14 [hazard ratio (HR) 2.98, 95% CI 1.57–5.67], longer interval from stroke to acute symptomatic seizures (days 4–7 post-stroke) (HR 2.51, 95% CI 1.37–4.59) and multiple acute symptomatic seizures (HR 5.08, 95% CI 2.58–9.99) were independently associated with PSE development. This association remained in the sub-analysis within the ischemic stroke cohort. In the sub-analysis of the hemorrhagic stroke cohort, multilobar involvement (HR 4.80, 95% CI 1.49–15.39) was also independently associated with development of PSE. Further, we developed a nomogram to predict individual risk of developing PSE following stroke-associated acute symptomatic seizures. The nomogram showed a C-index of 0.73.

Conclusion: More severe neurofunctional deficits (NIHSS score > 14), longer interval from stroke to acute symptomatic seizures (days 4–7 post-stroke), and multiple acute symptomatic seizures were independently associated with development of PSE in patients with stroke-associated acute symptomatic seizures. This knowledge may increase clinical vigilance for development of PSE, facilitating rapid diagnosis and treatment initiation, and subsequently reduce seizure-related morbidity.

Epilepsy in a health district in North-West Cameroon: Clinical characteristics and treatment gap

INTRODUCTION

Epilepsy is a common yet misunderstood condition in Cameroon, including in the Batibo Health district.

METHODS

This cross-sectional study describes epilepsy clinical characteristics, the treatment gap, and associated factors in a rural district in Cameroon. After screening for epilepsy using a door-to-door survey, physicians confirmed suspected cases of epilepsy. Detailed information on the medical, seizure, and treatment history was collected from everyone with epilepsy, followed by a general and neurological examination.

RESULTS

We diagnosed 546 people with active epilepsy (at least one seizure in the previous 12 months). The mean age of people with active epilepsy was 25.2 years (SD: 11.1). The mean age at first seizure was 12.5 years (SD: 8.2). Convulsive seizures (uncertain whether generalized or focal) were the most common seizure types (60%), while 41% had focal-onset seizures. About 60% of people had seizures at least monthly. One-quarter of participants had had at least one episode of status epilepticus. Anti-seizure medication (ASM) was taken by 85%, but most were receiving inappropriate treatment or were non-adherent, hence the high treatment gap (80%). Almost a third had had seizure-related injuries. Epilepsy was responsible for low school attendance; 74% of school dropouts were because of epilepsy.

CONCLUSION

The high proportion of focal-onset seizures suggests acquired causes (such as neurocysticercosis and onchocerciasis, both endemic in this area). The high epilepsy treatment gap and the high rates of status epilepticus and epilepsy-related injuries underscore the high burden of epilepsy in this rural Cameroonian health district.

Incidence and prevalence of epilepsy and associated factors in a health district in North-West Cameroon: A population survey

This population-based cross-sectional survey with a follow-up case-control study assessed the prevalence, incidence, and risk factors for epilepsy in a rural health district in the North-West Region of Cameroon. Community-based epilepsy screening targeted all inhabitants, six years and older, in all 16 health areas in the Batibo Health District. During door-to-door visits, trained fieldworkers used a validated questionnaire to interview consenting household heads to screen for epilepsy in eligible residents. Trained physicians subsequently assessed people with suspected seizures. After clinical assessment, they confirmed or refuted the diagnosis and estimated the date of epilepsy onset. A trained nurse interviewed people with epilepsy and randomly selected healthy individuals, obtaining relevant demographic details and information on exposure to risk factors for epilepsy. Out of 36,282 residents screened, 524 had active epilepsy. The age-standardized prevalence of active epilepsy was 33.9/1,000 (95% CI: 31.0-37.1/1,000). We estimated the one-year age-standardized epilepsy incidence at 171/100,000 (95%CI: 114.0-254.6). Active epilepsy prevalence varied widely between health areas, ranging between 12 and 75 per 1,000. The peak age-specific prevalence was in the 25-34 age group. In adults, multivariate analysis showed that having a relative with epilepsy was positively associated with epilepsy. Epilepsy characteristics in this population, geographical heterogeneity, and the age-specific prevalence pattern suggest that endemic neurocysticercosis and onchocerciasis may be implicated. Further investigations are warranted to establish the full range of risk factors for epilepsy in this population.

Understanding cardiovascular disease in older adults with epilepsy

OBJECTIVE

This study was undertaken to investigate the distribution of social, lifestyle/behavior, and chronic disease risk factors for cardiovascular disease (CVD) in people with epilepsy as compared to the general population. We also measured the cross-sectional association between epilepsy and CVD in older adults, with and without adjustments for a history of stroke.

METHODS

We analyzed data for 44 817 participants in the Canadian Longitudinal Study on Aging, including 751 individuals with a lifetime history of epilepsy. We modeled associations using ordinal and binomial logistic regression, as well as log-binomial regression, with multiple imputation for missing data. We measured the attributable fraction of CVD burden due to stroke.

RESULTS

The majority of the CVD risk factors were significantly more prevalent in people with epilepsy as compared to the general population without epilepsy, independent of age and sex. After adjusting for a history of stroke, people with epilepsy had a significantly higher prevalence of heart disease (prevalence ratio [PR] = 1.27, 95% confidence interval [CI] = 1.02-1.57) and peripheral vascular disease (PR = 1.88, 95% CI = 1.50-2.36). Stroke accounted for 36% (95% CI = 19.85-48.76) of the increased prevalence of any CVD among people with epilepsy, similar to the 32% (95% CI = 27.82-36.25) among people without epilepsy. After adjustment for all other CVD risk factors, peripheral vascular disease remained significantly more prevalent (PR = 1.65, 95% CI = 1.28-2.12) in people with epilepsy as compared to those without.

SIGNIFICANCE

CVD risk factors are more prevalent in people with epilepsy, independent of age and sex, and the association between epilepsy and CVD is independent of the association between epilepsy and stroke. The association between peripheral vascular disease and epilepsy may differ from the associations with other types of CVD. These findings are important steps in more comprehensively understanding the origins of CVD in people with epilepsy.

Abrupt darkening under high dynamic range (HDR) luminance invokes facilitation for high-contrast targets and grouping by luminance similarity

When scanning across a scene, luminance can vary by up to 100,000-to-1 (high dynamic range, HDR), requiring multiple normalizing mechanisms spanning from the retina to the cortex to support visual acuity and recognition. Vision models based on standard dynamic range (SDR) luminance contrast ratios below 100-to-1 have limited ability to generalize to real-world scenes with HDR luminance. To characterize how orientation and luminance are linked in brain mechanisms for luminance normalization, we measured orientation discrimination of Gabor targets under HDR luminance dynamics. We report a novel phenomenon, that abrupt 10- to 100-fold darkening engages contextual facilitation, distorting the apparent orientation of a high-contrast central target. Surprisingly, facilitation was influenced by grouping by luminance similarity, as well as by the degree of luminance variability in the surround. These results challenge vision models based solely on activity normalization and raise new questions that will lead to models that perform better in real-world scenes.

Validation of Malay brief screening instrument for ascertainment of epilepsy

INTRODUCTION

Prevalence studies of epilepsy in Asia revealed a prevalence ranging from 1.5 to 14.0 per 1000 among Asian populations. However, the prevalence of epilepsy in Malaysia is not available for comparison with other countries. This study aimed to translate and validate a Malay brief screening instruments for ascertainment of epilepsy.

METHOD

We translated into Malay a brief screening instrument for ascertainment of epilepsy designed and validated by Ottman et al., using the three-stage cross-cultural adaptation process developed by the International Quality of Life Assessment (IQOLA) project. We then administered the translated questionnaire via online survey to 162 cases (patients with epilepsy under follow-up care at the neurology clinic in University of Malaya Medical Centre, Kuala Lumpur) and 146 controls with no known history of epilepsy for validation.

RESULTS

Applying the most liberal definition for a positive screen, we obtained a sensitivity of 96.3% (95% confidence interval [CI]: 91.8-98.5%), with a specificity of 66.4% (95% CI: 58.1-73.0%) and positive predictive value (PPV) of 2.0%. The most stringent definition for a positive screen (only epilepsy) resulted in a sensitivity of 97.4% (95% CI: 62.0-72.6%), specificity of 98.6% (95% CI: 94.6-99.7%), and PPV of 26.6%. Narrowing the definition of a positive screen decreased sensitivity but improved PPVs. When compared to the original English questionnaire, the sensitivities were similar for all four definitions of a positive screen.

CONCLUSION

This is the first validated epilepsy screening questionnaire in the Malay language and represents a useful tool for the ascertainment of epilepsy in population-based studies.

A screening questionnaire for generalized tonic-clonic seizures: Hospital-based validation vs field-validation method

The majority of the screening questionnaires for epilepsy have been validated in hospital settings. We previously developed and used for field validation a screening tool to detect generalized tonic-clonic seizures (GTCS) in the rural communities of the Chaco region of Bolivia. The objective of the present study was to perform a hospital-based validation of the same questionnaire and to compare the levels of accuracy obtained when validated in the field or in a hospital-based context. We carried out a hospital-based validation in the Hospital Hernandez Vera of Santa Cruz, Bolivia, where we enrolled patients affected by epilepsy with GTCS and controls. Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated. One hundred twenty questionnaires were administered to 59 patients (27 men [45.8%]; mean age ± SD = 32.4 ± 14.2 years) and 61 controls (27 men [44.3%]; mean age ± SD = 32.6 ± 14.3 years). We obtained levels of accuracy of 100%. Sensitivity and PPV were significantly higher than the estimates obtained in the field-validation study (sensitivity 100% vs 76.3%; PPV 100% vs 69.0%). Our screening questionnaire showed a significantly lower level of sensitivity when validated in the field, confirming that hospital-based validation can lead to an overestimation of sensitivity.

Association between different acute stroke therapies and development of post stroke seizures

Background

Epilepsy is a major complication of stroke. We aimed to establish whether there is an association between intravenous thrombolysis, intra-arterial thrombolysis and post stroke seizure (PSS) development. Improved understanding of the relationship between reperfusion therapies and seizure development may improve post-stroke monitoring and follow-up.

Methods

This was a retrospective, multicentre cohort study conducted at the Royal Melbourne Hospital and Jingling Hospital Nanjing. We included patients with anterior circulation ischemic stroke admitted 2008–2015. Patients were divided into four treatment groups 1. IV-tPA only, 2. Intra-arterial therapies (IAT) only, 3. IAT + IV-tPA and 4. stroke unit care only (i.e. no IV-tPA or IAT). To assess the association between type of reperfusion treatment and seizure incidence we used multivariable logistic regression models adjusted for age, stroke severity, 3-month functional outcome and prognostic factors.

Results

There were 1375 stroke unit care-only patients, of whom 28 (2%) developed PSS. There were 363 patients who received only IV-tPA, of whom 21 (5.8%) developed PSS. There were 93 patients who received IAT only, of whom 12 (12.9%) developed PSS and 112 that received both IV-tPA + IAT, of which 5 (4.5%) developed PSS. All reperfusion treatments were associated with seizure development compared to stroke unit care-only patients: IV-tPA only adjusted odds ratio (aOR) 3.7, 95%CI 1.8–7.4, p < 0.0001; IAT aOR 5.5, 95%CI 2.1–14.3, p < 0.0001, IAT + IV-tPA aOR 3.4, 95% CI 0.98–11.8, p = 0.05. These aORs did not differ significantly between treatment groups (IV-tPA + IAT versus IV-tPA p = 0.89, IV-tPA + IAT versus IAT, p = 0.44).

Conclusions

Patients receiving thrombolytic or intra-arterial reperfusion therapies for acute ischemic stroke are at higher risk of epilepsy and may benefit from longer follow-up. No evidence for an additive or synergistic effect of treatment modality on seizure development was found.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1064-x) contains supplementary material, which is available to authorized users.

Association between implementation of a code stroke system and poststroke epilepsy

Objective

We aimed to investigate the effect of a code stroke system on the development of poststroke epilepsy.

Methods

We retrospectively analyzed consecutive patients treated with IV thrombolysis under or outside the code stroke system between 2003 and 2012. Patients were followed up for at least 2 years or until death. Factors with p < 0.1 in univariate comparisons were selected for multivariable logistic and Cox regression.

Results

A total of 409 patients met the eligibility criteria. Their median age at stroke onset was 75 years (interquartile range 64–83 years); 220 (53.8%) were male. The median follow-up duration was 1,074 days (interquartile range 119–1,671 days). Thirty-two patients (7.8%) had poststroke seizures during follow-up, comprising 7 (1.7%) with acute symptomatic seizures and 25 (6.1%) with late-onset seizures. Twenty-six patients (6.4%) fulfilled the definition of poststroke epilepsy. Three hundred eighteen patients (77.8%) were treated with the code stroke system while 91 (22.2%) were not. After adjustment for age and stroke etiology, use of the code stroke system was associated with decreased odds of poststroke epilepsy (odds ratio = 0.36, 95% confidence interval 0.14–0.87, p = 0.024). Cox regression showed lower adjusted hazard rates for poststroke epilepsy within 5 years for patients managed under the code stroke system (hazard ratio = 0.60, 95% confidence interval 0.47–0.79, p < 0.001).

Conclusion

The code stroke system was associated with reduced odds and instantaneous risk of poststroke epilepsy. Further studies are required to identify the contribution of the individual components and mechanisms against epileptogenesis after stroke.

Classification of evidence

This study provides Class III evidence that for people with acute ischemic stroke, implementation of a code stroke system reduces the risk of poststroke epilepsy.