Adult onset epilepsy incidence in Finland over 34 years: A nationwide registry study

Background and purpose

The incidence of epilepsy is decreasing among the working‐aged in high‐income countries, but previous studies have reported conflicting results in Finland.

Methods

A nationwide population‐based cross‐sectional analysis was made of annual epilepsy drug reimbursement rights frequency data from the Social Insurance Institution of Finland, the national authority, between 1986 and 2019. All persons at least 20 years of age living in Finland during the study period were included.

Results

Based on the analysis of 77,939 new reimbursement rights, crude incidence was 57.4/100,000 (95% confidence interval [CI] = 57.0–57.8) person‐years, and age‐standardized (to the European Standard Population 2013) incidence was 51.6/100,000 person‐years. Both crude (r = 0.62, p = 0.00009) and standardized (r = 0.65, p = 0.00003) incidence increased over time. Incidence increased in both men (from 66.4 to 71.6/100,000, r = 0.51, p = 0.002) and women (from 51.5 to 55.3/100,000, r = 0.68, p < 0.00001). The mean male to female incidence rate ratio was 1.28 (95% CI = 1.26–1.30, range = 1.15–1.41), but decreased during the study period (r = −0.47, p = 0.006). Incidence decreased in those 20–59 years old but increased in all older age groups. This development was similar between sexes.

Conclusions

The incidence of adult onset epilepsy in Finland increased in people older than 60 years and decreased in the 20–59‐year age group during the study period. These trends were similar between sexes. Therefore, etiological epilepsy trends in the elderly need to be studied further to plan public health measures to prevent epilepsy in this age group.

Cognitive functioning in progressive myoclonus epilepsy type 1 (Unverricht-Lundborg Disease, EPM1)

OBJECTIVE

The aim of this neuropsychological study of a large cohort of patients with progressive myoclonus epilepsy type 1 (Unverricht-Lundborg disease, EPM1) was to characterize the cognitive function of EPM1 patients and to explore the association between the disability caused by the disease and cognitive performance.

METHOD

Sixty-eight genetically verified EPM1 patients homozygous for the expansion mutation in the CSTB gene (37 males and 31 females aged 35 ± 11) participated in a neuropsychological assessment of intellectual ability, verbal memory, and executive and psychomotor function. The clinical evaluation comprised administering (and video-recording) the unified myoclonus rating scale (UMRS) to assess the severity of each patient's myoclonus. Forty-six healthy volunteers (19 males and 27 females aged 32 ± 11) served as the control group for the neuropsychological tests.

RESULTS

The cognitive performance of the EPM1 patient group was impaired. Verbal Intelligence Quotient (VIQ) was below the average range (VIQ < 85) in 49% of the patients; further, Performance Intelligence Quotient (PIQ) was below average in 75% of the patients. The patients performed worse than the controls in both immediate and delayed story recall (p = 0.001); however, in the word list learning task, the patients performed only slightly worse than the controls. The one-hour delayed recall of the learned words was similar in both groups, and the percentage of retained words and story contents did not differ between the patients and controls. The patients were impaired in all of the executive function tests as well as in the psychomotor speed tests (p < 0.001 for all). Also, the patients' simple psychomotor speed in the tapping task was significantly slowed in comparison to controls (p < 0.001).

CONCLUSION

The patients had impaired performance in the majority of the cognitive measures; they showed the highest level of impairment in all the executive function tests and in the psychomotor speed tests. The measures of these cognitive domains are timed-therefore, it is clear that severe myoclonus limits patients' performance. In contrast, verbal memory, especially delayed recall, was the least affected cognitive domain.

Wearable monitoring of positive and negative myoclonus in progressive myoclonic epilepsy type 1

OBJECTIVE

To develop and test wearable monitoring of surface electromyography and motion for detection and quantification of positive and negative myoclonus in patients with progressive myoclonic epilepsy type 1 (EPM1).

METHODS

Surface electromyography and three-dimensional acceleration were measured from 23 EPM1 patients from the biceps brachii (BB) of the dominant and the extensor digitorum communis (EDC) of the non-dominant arm for 48 hours. The patients self-reported the degree of myoclonus in a diary once an hour. Severity of myoclonus with action was evaluated by using video-recorded Unified Myoclonus Rating Scale (UMRS). Correlations of monitored parameters were quantified with the UMRS scores and the self-reported degrees of myoclonus.

RESULTS

The monitoring-based myoclonus index correlated significantly (p < 0.001) with the UMRS scores (ρ = 0.883 for BB and ρ = 0.823 for EDC) and with the self-reported myoclonus degrees (ρ = 0.483 for BB and ρ = 0.443 for EDC). Ten patients were assessed as probably having negative myoclonus in UMRS, while our algorithm detected that in twelve patients.

CONCLUSIONS

Wearable monitoring was able to detect both positive and negative myoclonus in EPM1 patients.

SIGNIFICANCE

Our method is suitable for quantifying objective, real-life treatment effects at home and progression of myoclonus.

Artificial intelligence for classification of temporal lobe epilepsy with ROI-level MRI data: A worldwide ENIGMA-Epilepsy study

Artificial intelligence has recently gained popularity across different medical fields to aid in the detection of diseases based on pathology samples or medical imaging findings. Brain magnetic resonance imaging (MRI) is a key assessment tool for patients with temporal lobe epilepsy (TLE). The role of machine learning and artificial intelligence to increase detection of brain abnormalities in TLE remains inconclusive. We used support vector machine (SV) and deep learning (DL) models based on region of interest (ROI-based) structural (n = 336) and diffusion (n = 863) brain MRI data from patients with TLE with ("lesional") and without ("non-lesional") radiographic features suggestive of underlying hippocampal sclerosis from the multinational (multi-center) ENIGMA-Epilepsy consortium. Our data showed that models to identify TLE performed better or similar (68-75%) compared to models to lateralize the side of TLE (56-73%, except structural-based) based on diffusion data with the opposite pattern seen for structural data (67-75% to diagnose vs. 83% to lateralize). In other aspects, structural and diffusion-based models showed similar classification accuracies. Our classification models for patients with hippocampal sclerosis were more accurate (68-76%) than models that stratified non-lesional patients (53-62%). Overall, SV and DL models performed similarly with several instances in which SV mildly outperformed DL. We discuss the relative performance of these models with ROI-level data and the implications for future applications of machine learning and artificial intelligence in epilepsy care.

Impact of diagnostic delay on seizure outcome in newly diagnosed focal epilepsy

OBJECTIVE

In the current study, we aimed to assess the diagnostic delay and the impact of diagnostic delay on seizure outcome in a cohort of newly diagnosed patients with focal epilepsy.

METHODS

The study material was compiled from eight clinical antiseizure medication monotherapy trials conducted at Kuopio Epilepsy Center during 1995-2016. We analyzed the time from first seizure to diagnosis, the number of seizures before diagnosis, and the response to treatment at five years.

RESULTS

Of the 176 patients (age range 15-75 years) in the cohort, 135 (77%) had had more than two seizures before treatment. The majority of these (79 patients, 45%) had had three to ten seizures. Median number of all seizures before diagnosis was 5 (range 2-2000). Focal aware seizures and focal impaired awareness seizures were more frequent than focal to bilateral tonic-clonic seizures; median number 45 (range 2-2000), 11 (range 2-220), and 3 (range 2-30), respectively (P < .001). Median delay was 12 months (range 0-362). Diagnostic delay alone did not correlate with the treatment response at five years. However, an increasing number of seizures before diagnosis indicated a worse seizure outcome (P < .001).

SIGNIFICANCE

This study shows that patients with focal epilepsy experience significant delays in diagnosis even in developed countries, especially with seizure types other than tonic-clonic seizures. In these cases, a long delay in diagnosis alone might not affect the long-term outcome. However, when accompanied with recurrent seizures misinterpreted by the patient or healthcare providers, the effect of such delay on prognosis can be considerable.

Network-based atrophy modeling in the common epilepsies: A worldwide ENIGMA study

Epilepsy is increasingly conceptualized as a network disorder. In this cross-sectional mega-analysis, we integrated neuroimaging and connectome analysis to identify network associations with atrophy patterns in 1021 adults with epilepsy compared to 1564 healthy controls from 19 international sites. In temporal lobe epilepsy, areas of atrophy colocalized with highly interconnected cortical hub regions, whereas idiopathic generalized epilepsy showed preferential subcortical hub involvement. These morphological abnormalities were anchored to the connectivity profiles of distinct disease epicenters, pointing to temporo-limbic cortices in temporal lobe epilepsy and fronto-central cortices in idiopathic generalized epilepsy. Negative effects of age on atrophy further revealed a strong influence of connectome architecture in temporal lobe, but not idiopathic generalized, epilepsy. Our findings were reproduced across individual sites and single patients and were robust across different analytical methods. Through worldwide collaboration in ENIGMA-Epilepsy, we provided deeper insights into the macroscale features that shape the pathophysiology of common epilepsies.

Unverricht-Lundborg disease (EPM1) in Finland: A nationwide population-based study

OBJECTIVE

To investigate the epidemiology and prognosis of Unverricht-Lundborg disease (EPM1) in a nationwide, population-based setting.

METHODS

Data from multiple registries were combined and analyzed. Clinical data were obtained from medical records. All patients treated for EPM1 in Finland between January 1, 1998, and December 31, 2016 were included.

RESULTS

A total of 135 persons with EPM1 (54% women) were identified and 105 were alive on December 31, 2016 (point prevalence 1.91/100,000 persons). The age-standardized (European Standard Population 2013) prevalence was 1.53/100,000 persons. Annual incidence during the study period was 0.022/100,000 person-years, with a mean age at onset of 9.4 ± 2.3 years (range 7.0-14.6 years, no sex difference). The median age at death (n = 34) was 53.9 years (interquartile range 46.4, 60.3; range 23.2-63.8), with no sex differences. The immediate cause of death was a lower respiratory tract infection in 56% of deaths. The survival rates of the patients were comparable to matched controls up to 40 years of age, but poorer during long-term follow-up (cumulative survival 26.4% vs 78.0%), with a hazard ratio (HR) for death of 4.61. The risk of death decreased with increasing age at onset (HR 0.76 per year, 95% confidence interval 0.65-0.89). In approximately 10% of all cases, the disease progression appeared very mild; some patients retained functional independence for decades.

CONCLUSIONS

Unverricht-Lundborg disease is rare in Finland but still more common than anywhere else in the world. The disease course appears somewhat more severe than elsewhere, disability mounts early, and death occurs prematurely.

Lacosamide in patients with epilepsy of cerebrovascular etiology

OBJECTIVES

To assess tolerability and efficacy of lacosamide in adults with cerebrovascular epilepsy etiology (CVEE).

MATERIALS AND METHODS

Exploratory post hoc analyses of a double-blind, initial monotherapy trial of lacosamide vs carbamazepine-controlled release (carbamazepine-CR) (SP0993; NCT01243177); a double-blind conversion to lacosamide monotherapy trial (SP0902; NCT00520741); and an observational study of adjunctive lacosamide added to one antiepileptic drug (SP0973 VITOBA; NCT01098162). Patients with CVEE were identified based on epilepsy etiology recorded at baseline.

RESULTS

In the initial monotherapy trial, 61 patients had CVEE (lacosamide: 27; carbamazepine-CR: 34). 20 (74.1%) patients on lacosamide (27 [79.4%] on carbamazepine-CR) reported treatment-emergent adverse events (TEAEs), most commonly (≥10%) headache, dizziness, and fatigue (carbamazepine-CR: headache, dizziness). A numerically higher proportion of patients on lacosamide than carbamazepine-CR completed 6 months (22 [81.5%]; 20 [58.8%]) and 12 months (18 [66.7%]; 17 [50.0%]) treatment without seizure at last evaluated dose. In the conversion to monotherapy trial, 26/30 (86.7%) patients with CVEE reported TEAEs, most commonly (≥4 patients) dizziness, convulsion, fatigue, headache, somnolence, and cognitive disorder. During lacosamide monotherapy, 17 (56.7%) patients were 50% responders and six (20.0%) were seizure-free. In the observational study, 36/83 (43.4%) patients with CVEE reported TEAEs, most commonly (≥5%) fatigue and dizziness. Effectiveness was assessed for 75 patients. During the last 3 months, 60 (80%) were 50% responders and 42 (56.0%) were seizure-free.

CONCLUSIONS

These exploratory post hoc analyses suggested lacosamide was generally well tolerated and effective in patients with CVEE, with data from the initial monotherapy trial suggesting numerically better efficacy than carbamazepine-CR.

The ENIGMA-Epilepsy working group: Mapping disease from large data sets

Epilepsy is a common and serious neurological disorder, with many different constituent conditions characterized by their electro clinical, imaging, and genetic features. MRI has been fundamental in advancing our understanding of brain processes in the epilepsies. Smaller-scale studies have identified many interesting imaging phenomena, with implications both for understanding pathophysiology and improving clinical care. Through the infrastructure and concepts now well-established by the ENIGMA Consortium, ENIGMA-Epilepsy was established to strengthen epilepsy neuroscience by greatly increasing sample sizes, leveraging ideas and methods established in other ENIGMA projects, and generating a body of collaborating scientists and clinicians to drive forward robust research. Here we review published, current, and future projects, that include structural MRI, diffusion tensor imaging (DTI), and resting state functional MRI (rsfMRI), and that employ advanced methods including structural covariance, and event-based modeling analysis. We explore age of onset- and duration-related features, as well as phenomena-specific work focusing on particular epilepsy syndromes or phenotypes, multimodal analyses focused on understanding the biology of disease progression, and deep learning approaches. We encourage groups who may be interested in participating to make contact to further grow and develop ENIGMA-Epilepsy.

Cognitive functioning in new-onset juvenile myoclonic epilepsy

PURPOSE

Juvenile myoclonic epilepsy (JME) is a common genetic generalized epilepsy syndrome. Adult patients with JME have shown a neuropsychological profile suggestive of subtle frontal dysfunction, but studies of cognitive functioning in the early phases of JME are rare. We analyzed the cognitive performance data of 18 patients who had undergone a neuropsychological assessment either at the time of JME diagnosis and before the initiation of an antiepileptic drug (AED) treatment (11 patients) or during the first 6 years after JME diagnosis (seven patients).

METHODS

The cognitive performance of the18 patients with JME (mean age: 18.1, range: 15-33 years) and 18 healthy controls (mean age: 18.7, range: 15-25 years) was compared in a retrospective study. The assessed cognitive domains were visuomotor speed, attention, executive function, and verbal memory.

RESULTS

The patients with JME and the healthy controls did not differ in any of the assessed cognitive domains. The clinical variables did not correlate to cognitive performance. Furthermore, cognitive performance did not differ between the patients evaluated at the time of diagnosis and before the initiation of AEDs and the patients evaluated during the first 6 years after diagnosis and with an AED treatment.

CONCLUSIONS

The cognitive performance of patients with new-onset JME was similar to healthy controls. We could not detect the frontal dysfunction that has been suggested to be associated with JME. Patients were in adolescence or early adulthood with a short duration of epilepsy, which may have contributed to the discovery of no cognitive impairments.

Automatic assessment of the myoclonus severity from videos recorded according to standardized Unified Myoclonus Rating Scale protocol and using human pose and body movement analysis

PURPOSE

Myoclonus in progressive myoclonus epilepsy type 1 (EPM1) patients shows marked variability, which presents a substantial challenge in devising treatment and conducting clinical trials. Consequently, fast and objective myoclonus quantification methods are needed.

METHODS

Ten video-recorded unified myoclonus rating scale (UMRS) myoclonus with action tests were performed on EPM1 patients who were selected for the development and testing of the automatic myoclonus quantification method. Human pose and body movement analyses of the videos were used to identify body keypoints and further analyze movement smoothness and speed. The automatic myoclonus rating scale (ARMS) was developed. It included the jerk count during movement score and the log dimensionless jerk (LDLJ) score to evaluate changes in the smoothness of movement.

RESULTS

The scores obtained with the automatic analyses showed moderate to strong significant correlation with the UMRS myoclonus with action scores. The jerk count of the primary keypoints and the LDLJ scores were effective in the evaluation of the myoclonic jerks during hand movements. They also correlated moderately to strongly with the total UMRS test panel scores (r2 = 0,77, P = 0,009 for the jerk count score and r2 = 0,88, P = 0,001 for the LDLJ score). The automatic analyses was weaker in quantification of the neck, trunk, and leg myoclonus.

CONCLUSION

Automatic quantification of myoclonic jerks using human pose and body movement analysis of patients' videos is feasible and was found to be quite consistent with the accepted clinical gold standard quantification method. Based on the results of this study, the automatic analytical method should be further developed and validated to improve myoclonus severity follow-up for EPM1 patients.

Economic Value of Adjunctive Brivaracetam Treatment Strategy for Focal Onset Seizures in Finland

Introduction

There is an unmet need for well-tolerated antiepileptic drugs (AEDs) that effectively control focal onset seizures. This study aimed to evaluate the economic value of new AEDs in the treatment of focal onset seizure, with or without secondary generalization, in Finnish adults and adolescents with epilepsy, comparing brivaracetam with perampanel as adjunctive AEDs.

Methods

Economic value was assessed using cost-utility analysis. Periods of AED initiation, titration, response assessment (seizure freedom, ≥ 50% reduction, no response), switching in no response or treatment-emergent adverse events (TEAEs), and death were simulated using a discrete-event simulation model. Responses and switching were simulated based on a comprehensive Bayesian network meta-analysis. The primary modeled outcome was the 3%/year discounted incremental cost-effectiveness ratio (ICER). Discounted quality-adjusted life-years (QALYs), payer costs (year 2017 Euro) per patient, and net monetary benefit (NMB) were secondary outcomes. Probabilistic and comprehensive deterministic sensitivity analyses were conducted.

Results

Brivaracetam was more efficacious and had fewer TEAEs than perampanel and other AEDs. Modeled average 5-year QALYs and costs were 3.671 and €28,297 for brivaracetam and 3.611 and €27,979 for perampanel, respectively. The resulting ICER for brivaracetam versus perampanel was only €5345/QALY gained in a deterministic base case scenario. Brivaracetam had a positive NMB and high probability of cost-effectiveness of €1190 and 71% or €1944 and 80% with the assumed willingness to pay of €25,358 or €38,036/QALY gained, respectively. The primary result was robust, with a positive NMB persistent in all sensitivity analysis scenarios. When switching from brivaracetam to perampanel was excluded from the modeling or switching from perampanel to brivaracetam was included, brivaracetam was cost-saving and more effective than perampanel (dominant).

Conclusion

These simulated comparisons demonstrated that brivaracetam was more effective and potentially also more affordable than perampanel. Thus, brivaracetam is likely a cost-effective and net beneficial alternative to perampanel for treatment of focal onset seizures.

Plain Language Summary

Plain language summary available for this article.

Electronic supplementary material

The online version of this article (10.1007/s12325-019-01155-6) contains supplementary material, which is available to authorized users.

Incidence of the different stages of status epilepticus in Eastern Finland: A population-based study

OBJECTIVE

The objective of this study was to determine the incidence in Eastern Finland of the different stages of status epilepticus (SE): 1) at the early stage of SE (a prolonged seizure lasting over 5 min);, 2) refractory SE (RSE), and 3) super-refractory SE (SRSE).

METHODS

Firstly, we conducted a retrospective study on the incidence and outcome of intensive care unit (ICU)-treated RSE and SRSE in the adult population (≥16 years) in Kuopio University Hospital (KUH)'s special care responsibility area (840,000 inhabitants). Secondly, we conducted a prospective study using the International League Against Epilepsy (ILAE)'s new definition for SE (prolonged seizures lasting over 5 min), in adult (≥16 years) patients in the KUH municipality district (North Savo, 248,000 inhabitants).

RESULTS

The retrospective study on ICU-treated RSE and SRSE from 2010 to 2012 identified 75 patients with RSE, of whom 21% were treated as SRSE, resulting in an annual age-adjusted incidence of ICU-treated RSE of 3.0/100,000 (95% confidence interval [CI]: 2.4-3.8) and 0.6/100,000 (95% CI: 0.4-1.0) for SRSE. In the prospective study of early stage SE (seizures lasting over 5 min), we identified 151 consecutive episodes during the 9-month study period in 2015, corresponding to an annual age-adjusted incidence of 81.1/100,000 (95% CI: 75.8-87.0). In this study, 11 seizure episodes became refractory, resulting in an age-adjusted incidence of RSE of 6.0/100,000 (95% CI: 3.4-10.4), of which seven were treated in the ICU [3.8/100,000 (95% CI: 1.8-7.8)], four were treated palliatively [2.2/100,000 (95% CI: 0.82-5.7)], and two evolved to SRSE [1.1/100,000 (95% CI: 0.3-4.3)].

CONCLUSIONS

The new ILAE 2015 definition of SE resulted in a four-fold increase in incidence of SE compared to the earlier 30-min definition reported earlier in Europe. In the epidemiology of RSE, the incidence of ICU-treated RSE, palliatively treated RSE, and SRSE needs to be separated. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures.

Management of prolonged epileptic seizures and status epilepticus in palliative care patients

Prolonged seizures and status epilepticus (SE) are relevant problems in palliative care. Timely recognition and effective early treatment with first- and second-line antiepileptic drugs (AEDs) may prevent unnecessary hospitalizations. Seizures should be recognized and addressed like any other symptom that causes discomfort or reduces quality of life. Use of alternative AED administration routes (buccal, intranasal, or subcutaneous) may offer possibilities for effective and individualized AED therapy, even during the last days of life. In hospice or home care, however, also intravenous treatment is possible via vascular access devices for long-term use. Aggressive unlimited intensive care unit (ICU) treatment of refractory SE in palliative patients is mostly not indicated. At worst, intensive care can be futile and possibly harmful: death in the ICU is often preceded by long and aggressive treatments. Metastatic cancer, old age, high severity of acute illness, overall frailty, poor functional status before hospital admission, and the presence of severe comorbidities all increase the probability of poor outcome of intensive care. When several of these factors are present, consideration of withholding intensive care may be in the patient's best interests. Anticipated outcomes influence patients' preferences. A majority of patients with a limited life expectancy because of an incurable disease would not want aggressive treatment, if the anticipated outcome was survival but with severe functional impairment. Doctors' perceptions about their patients' wishes are often incorrect, and therefore, advance care planning including seizure management should be done early in the course of the disease. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

Ultra-Rare Genetic Variation in the Epilepsies: A Whole-Exome Sequencing Study of 17,606 Individuals

Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABA_A receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.

Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study

Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen’s d = −0.24 to −0.73; P < 1.49 × 10⁻⁴), and lower thickness in the precentral gyri bilaterally (d = −0.34 to −0.52; P < 4.31 × 10⁻⁶). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = −1.73 to −1.91, P < 1.4 × 10⁻¹⁹), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = −0.36 to −0.52; P < 1.49 × 10⁻⁴). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = −0.29 to −0.54; P < 1.49 × 10⁻⁴). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = −0.27 to −0.51; P < 1.49 × 10⁻⁴). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < −0.0018; P < 1.49 × 10⁻⁴). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed.

Perampanel for treatment of status epilepticus in Austria, Finland, Germany, and Spain

OBJECTIVE

Novel treatments are needed to control treatment-resistant status epilepticus (SE). We report a summary of clinical cases where perampanel was used in established SE, refractory SE (RSE), or super-refractory SE (SRSE).

METHODS

Medical records were retrospectively reviewed for perampanel administration in SE at five European hospitals between 2011 and 2015.

RESULTS

Of 1319 patients identified as experiencing SE, 52 (3.9%) received perampanel. Median latency from SE onset to perampanel initiation was 10 days. Patients with SE had previously failed benzodiazepines (when received) and a median of five other antiepileptic drugs (AEDs). Median initial perampanel dose was 6 mg/d, up-titrated to a median maximum dose of 10 mg/d. Perampanel was the last drug added in 32/52 (61.5%) patients, with response attributed to perampanel in 19/52 (36.5%) patients. A greater proportion of perampanel non-responders had SRSE (51.5%; 17/33) vs perampanel responders (31.6%; 6/19), and had failed a higher mean number of AEDs before initiating perampanel (5.9 vs 5.1, respectively). Most commonly reported adverse effects during perampanel treatment were dizziness (n = 1 [1.9%]) and somnolence (n = 1 [1.9%]). No serious adverse effects were documented, and none led to discontinuation of perampanel.

CONCLUSIONS

Perampanel was administered to patients with established SE, RSE, or SRSE at greater initial doses than those administered in clinical practice to patients with epilepsy. The SE cases reported here represent a refractory and heterogeneous population, and rate of seizure cessation attributed to perampanel treatment (36.5%) represents a notable response. These data should be confirmed in a larger patient population.

Variants p.Q1236H and p.E1143G in mitochondrial DNA polymerase gamma POLG1 are not associated with increased risk for valproate-induced hepatotoxicity or pancreatic toxicity: A retrospective cohort study of patients with epilepsy

OBJECTIVE

Previous studies have suggested that heterozygous variants p.Q1236H and p.E1143G in mitochondrial DNA polymerase gamma (POLG1) increase the risk for liver injury for patients on valproate (VPA) therapy. We assessed the prevalence of these common variants and seven other pathogenic mutations in POLG1 and determined the occurrence of VPA-induced hepatotoxicity (VHT) or pancreatic toxicity in a cohort of patients with epilepsy.

METHODS

Patients with epilepsy (N = 367) were retrospectively identified from medical record files and screened for mutations in POLG1. Patients who had received VPA monotherapy and carried either of the two variants, p.Q1236H or p.E1143G, without other pathogenic mutations in POLG1 (n = 33, variant group) and patients without these variants (n = 28, nonvariant group) were included in the study. Clinical data on epilepsy, characteristics of VPA treatment, risk factors for VHT, laboratory data on liver and pancreas functions, and adverse effects were collected.

RESULTS

A total of 122 patients had either the POLG1 p.Q1236H (n = 99) or p.E1143G (n = 24) variant in the heterozygous or homozygous state. Transient liver dysfunction was identified in three (n = 33, 9.1%) variant group patients and in one (n = 28, 3.6%) nonvariant group patient (P = 0.62). Mild to moderate elevations in liver enzymes were encountered in both groups. Furthermore, two patients on VPA polytherapy developed acute pancreatitis, and two pediatric patients with heterozygous p.Q1236H variants and mutations in IQSEC2 and GLDC, respectively, had elevated levels of VPA metabolites in urine, elevated plasma glycine, and/or increased acylglycine excretion.

SIGNIFICANCE

POLG1 p.Q1236H and p.E1143G variants could not be identified as statistically significant risk factors for VHT or pancreatic toxicity. We suggest that VPA treatment could be suitable for patients who harbor these common variants in the absence of other pathogenic mutations in POLG1.

Abnormal motor cortical adaptation to external stimulus in Unverricht-Lundborg disease (progressive myoclonus type 1, EPM1)

Unverricht-Lundborg disease (EPM1) is associated with progressive functional and anatomic changes in the thalamus and motor cortex. The neurophysiological mechanisms behind the impaired thalamocortical system were studied through short-term adaptation of the motor cortex to transcranial magnetic stimulation (TMS) via repetition suppression (RS) phenomenon. RS is considered to be related to neural processing of external stimuli. We hypothesized that this neural processing is progressively impaired in EPM1 from adolescence to adulthood. Eight adult patients with EPM1 (age: 40 ± 13 yr), six adolescent patients with EPM1 (age: 16 ± 1 yr), and ten adult controls (age: 35 ± 12 yr) were studied using navigated TMS and RS study protocol including trains of four repeated stimuli with intertrain interval of 20 s and interstimulus interval of 1 s. Changes in RS were investigated from adolescence to adulthood in EPM1 by comparing with adult controls. In controls, the RS was seen as 50-55% reduction in motor response amplitudes to TMS after the first stimulus. RS was mild or missing in EPM1. RS from first to second stimulus within the stimulus trains was significantly stronger in adolescent patients than in adult patients ( P = 0.046). Abnormal RS correlated with the myoclonus severity of the patients. In agreement with our hypothesis, neural processing of external stimuli is progressively impaired in EPM1 possibly due to anatomically impaired thalamocortical system or inhibitory tonus preventing sufficient adaptive reactiveness to stimuli. Our results suggest that RS abnormality might be used as a biomarker in the therapeutic trials for myoclonus. NEW & NOTEWORTHY Unverricht-Lundborg disease (EPM1) is associated with impaired thalamocortical function, which we studied in 8 adult and 6 adolescent patients and in 10 adult controls through repetition suppression (RS) of the motor cortex. We hypothesized that neural processing is progressively impaired in EPM1 from adolescence to adulthood. RS was normal in controls, whereas it was mild or missing in EPM1. Stronger RS was seen in adolescent patients than in adult patients correlating with the myoclonus severity.

Analysis of shared heritability in common disorders of the brain

Disorders of the brain can exhibit considerable epidemiological comorbidity and often share symptoms, provoking debate about their etiologic overlap. We quantified the genetic sharing of 25 brain disorders from genome-wide association studies of 265,218 patients and 784,643 control participants and assessed their relationship to 17 phenotypes from 1,191,588 individuals. Psychiatric disorders share common variant risk, whereas neurological disorders appear more distinct from one another and from the psychiatric disorders. We also identified significant sharing between disorders and a number of brain phenotypes, including cognitive measures. Further, we conducted simulations to explore how statistical power, diagnostic misclassification, and phenotypic heterogeneity affect genetic correlations. These results highlight the importance of common genetic variation as a risk factor for brain disorders and the value of heritability-based methods in understanding their etiology.

European trends in epilepsy surgery

OBJECTIVE

Resective surgery is effective in treating drug-resistant focal epilepsy, but it remains unclear whether improved diagnostics influence postsurgical outcomes. Here, we compared practice and outcomes over 2 periods 15 years apart.

METHODS

Sixteen European centers retrospectively identified 2 cohorts of children and adults who underwent epilepsy surgery in the period of 1997 to 1998 (n = 562) or 2012 to 2013 (n = 736). Data collected included patient (sex, age) and disease (duration, localization and diagnosis) characteristics, type of surgery, histopathology, Engel postsurgical outcome, and complications, as well as imaging and electrophysiologic tests performed for each case. Postsurgical outcome predictors were included in a multivariate logistic regression to assess the strength of date of surgery as an independent predictor.

RESULTS

Over time, the number of operated cases per center increased from a median of 31 to 50 per 2-year period (p = 0.02). Mean disease duration at surgery decreased by 5.2 years (p < 0.001). Overall seizure freedom (Engel class 1) increased from 66.7% to 70.9% (adjusted p = 0.04), despite an increase in complex surgeries (extratemporal and/or MRI negative). Surgeries performed during the later period were 1.34 times (adjusted odds ratio; 95% confidence interval 1.02-1.77) more likely to yield a favorable outcome (Engel class I) than earlier surgeries, and improvement was more marked in extratemporal and MRI-negative temporal epilepsy. The rate of persistent neurologic complications remained stable (4.6%-5.3%, p = 0.7).

CONCLUSION

Improvements in European epilepsy surgery over time are modest but significant, including higher surgical volume, shorter disease duration, and improved postsurgical seizure outcomes. Early referral for evaluation is required to continue on this encouraging trend.