Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: an EAN, ESRS and ILAE-Europe consensus review.

BACKGROUND AND PURPOSE: Some epilepsy syndromes (sleep-related epilepsies, SREs) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life. Our purpose was to define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2). METHODS: The project was conducted under the auspices of the European Academy of Neurology, the European Sleep Research Society and the International League Against Epilepsy Europe. The framework entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For the literature search a stepwise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library. RESULTS: Scenario 1: Despite a low quality of evidence, recommendations on anamnestic evaluation and tools for capturing the event at home or in the laboratory are provided for specific SREs. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizure control. CONCLUSIONS: Definitive procedures for evaluating patients with SRE are lacking. Advice is provided that could be of help for standardizing and improving the diagnostic approach of specific SREs. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Epidemiology and outcome of idiopathic generalized epilepsy in adults.

BACKGROUND AND PURPOSE: Drug-resistant idiopathic generalized epilepsy (IGE) remains challenging despite a favourable overall prognosis of IGE, and little is known about basic epidemiology and long-term outcome of drug-resistant IGE. The aim of the study was to describe the incidence, prevalence and outcome of IGE in an unbiased, population-based cohort. METHODS: In 2014-2018, all patients (≥17 years) with IGE inhabiting the island of Funen (496 000 inhabitants) were recruited. The socioeconomic and clinical information available for 406 individuals was assessed. Median follow-up was 15 years. RESULTS: The average IGE incidence (2008-2017) was 2.9/100 000 inhabitants/year. The point prevalence of identifiable IGE patients was 1.0/1000 adults (juvenile myoclonic epilepsy 0.4/1000; absence epilepsy 0.3/1000, epilepsy with generalized tonic-clonic seizures alone 0.3/1000); 92.1% of the patients were diagnosed before 25 years of age. When correcting for unequal age distribution in the cohort, 1102 people on the island of Funen fulfilled the diagnostic criteria for IGE at the age of 25 (estimated prevalence 2.7/1000 adults). In the year before data closure, 121 patients reported seizures. Fifty patients met the definition of drug-resistant IGE (12.1% of the cohort, 4.5% of the estimated 1102 IGE patients). The average seizure burden of all patients with drug-resistant IGE was 2.2 generalized tonic-clonic seizures per year; only 14 patients suffered more than two generalized tonic-clonic seizures per year. Drug-resistant IGE was associated with an increased risk of requiring treatment for affective disorders and a reduced probability of working full time. CONCLUSION: Idiopathic generalized epilepsy was associated with a low risk of persistent drug-resistant seizures requiring specialist medical attention. Drug resistance was associated with a negative socioeconomic outcome.

Ictal and interictal electric source imaging in pre-surgical evaluation: a prospective study.

BACKGROUND AND PURPOSE: Accurate localization of the epileptic focus is essential for surgical treatment of patients with drug-resistant epilepsy. Electric source imaging (ESI) is increasingly used in pre-surgical evaluation. However, most previous studies have analysed interictal (II) discharges. Prospective studies comparing the feasibility and accuracy of II and ictal (IC) ESI are lacking. METHODS: We prospectively analysed long-term video-electroencephalography recordings (LTM) of patients admitted for pre-surgical evaluation. We performed ESI of II and IC signals using two methods, i.e. equivalent current dipole (ECD) and a distributed source model (DSM). LTM recordings employed the standard 25-electrode array (including inferior temporal electrodes). An age-matched template head model was used for source analysis. Results were compared with intracranial recordings, conventional neuroimaging methods [magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT)] and outcome at 1 year after surgery. RESULTS: A total of 87 consecutive patients were analysed. ECD gave a significantly higher proportion of patients with localized focal abnormalities (94%) compared with MRI (70%), PET (66%) and SPECT (64%). Agreement between the ESI methods and intracranial recording was moderate to substantial (k = 0.56-0.79). A total of 54 patients were operated (47 patients more than 1 year ago) and 62% of them became seizure-free. The localization accuracy of II-ESI was 51% for DSM and 57% for ECD, and that for IC-ESI was 51% for DSM and 62% for ECD. The differences between the ESI methods were not significant. Differences in localization accuracy between ESI and MRI (55%), PET (33%) and SPECT (40%) were not significant. CONCLUSIONS: The II-ESI and IC-ESI of LTM data have high feasibility and their localization accuracy is similar to that of conventional neuroimaging methods.

Clinical utility of EEG in diagnosing and monitoring epilepsy in adults.

Electroencephalography (EEG) remains an essential diagnostic tool for people with epilepsy (PWE). The International Federation of Clinical Neurophysiology produces new guidelines as an educational service for clinicians to address gaps in knowledge in clinical neurophysiology. The current guideline was prepared in response to gaps present in epilepsy-related neurophysiological assessment and is not intended to replace sound clinical judgement in the care of PWE. Furthermore, addressing specific pathophysiological conditions of the brain that produce epilepsy is of primary importance though is beyond the scope of this guideline. Instead, our goal is to summarize the scientific evidence for the utility of EEG when diagnosing and monitoring PWE.

Add-on perampanel and aggressive behaviour in severe drug-resistant focal epilepsies.

This study aimed to investigate the incidence of aggressiveness in patients with severe drug-refractory focal epilepsy (DRE) who started perampanel (PER) as add-on treatment, and to identify possible predisposing factors. Data on 49 consecutive patients with severe DRE who initiated PER were retrospectively collected. Twelve of the 49 patients experienced aggressiveness as adverse event related to PER treatment, one third of them on low (2-4 mg/day) PER dosages. PER was discontinued in 10/12 patients because of aggressive behaviors. Aggressiveness could appear after several months or even more than one year of PER treatment. One third of patients with PER-related aggressiveness had intellectual disabilities and 5/12 patients took levetiracetam as a concomitant antiepileptic drug. Our study suggests that the occurrence of aggressive behaviors in patients with severe DRE is not uncommon during PER treatment and that it may occur after months or even years of treatment with a stable dosage, requiring PER discontinuation in the great majority of patients.

Perampanel as add-on treatment in refractory focal epilepsy. The Dianalund experience.

BACKGROUND: Perampanel (PER) is an antagonist of AMPA receptors that has been approved for adjunctive treatment of partial-onset seizures. AIMS: To evaluate effectiveness and safety of PER as add-on treatment in patients with severely refractory focal epilepsy. METHODS: PER was introduced as add-on treatment in 22 consecutive patients with drug-resistant focal epilepsy. PER was started with 2 mg/day at bedtime and was up-titrated by 2 mg/day every 2-4 weeks. RESULTS: All patients suffered from severely refractory focal epilepsy (86% took 2 or more AEDs prior PER initiation; 40% had been submitted to surgery or were surgery candidates; 7 had VNS). After 12 months since PER initiation, the retention rate was 54.5% and the responder rate was 27.2%, including 9.1% seizure-free patients. Mean PER dose in the responders was 8 mg/day (range 4-10). Most common side effects were tiredness, behavioral changes (primarily aggressivity), dizziness and were reported in 59.1% of patients, leading to PER discontinuation in 31.8% of subjects. CONCLUSIONS: PER as add-on treatment can achieve clinically meaningful improvement in patients suffering from severely refractory focal epilepses. Further studies are warranted to explore the tolerability profile, with particular focus on psychiatric adverse events.

Focal epilepsies associated with glioneuronal tumors: review article.

Glioneuronal tumors (GNTs) are an increasingly recognized cause of focal epilepsies, particularly in children and young adults. GNTs consist of a mixture of glial and neuronal elements and most commonly arise in the temporal lobe, particularly in the temporo-anterior-basal mesial site. They are often associated with cortical dysplasia or other neuronal migration abnormalities. Epilepsy associated with GNT is poorly controlled by antiepileptic drugs in many cases; but, it is extremely responsive to surgical treatment. However, the best management strategy of tumor-related focal epilepsies remains controversial and still remain one of the contemporary issues in epilepsy surgery. Temporo-mesial GNT are associated with a widespread epileptic network, defining, therefore, a distinct anatomo-clinico-pathological group with complex epileptogenic mechanisms. By using an epilepsy surgery oriented strategy GNT associated with focal epilepsies may have an excellent seizure outcome and, therefore, surgical treatment can be offered early to avoid both the consequences of uncontrolled seizures as well as the side effects of prolonged pharmacological therapy and the rare risk of tumor growth or malignant transformation.

Role of dentate gyrus alterations in mesial temporal sclerosis.

Drug-resistant chronic temporal lobe epilepsy is the most common type of epilepsy that undergoes surgical treatment. To verify if dentate gyrus alterations may play a role in patients with mesial temporal sclerosis (MTS), 14 patients, submitted to epilepsy surgery, were selected. Only cases with MTS alone were included. Granule cell dispersion (GCD) was observed in 7 cases (50%). A statistically significant correlation between GCD and the mean number of seizures/month was evidenced. The percentage of patients who did not achieve seizure relief (i.e. they were not in Engel class 1A) was 57.14% in patients without GCD, whereas that percentage dropped to 14.29% in patients with GCD. The association between a more favorable postsurgical epileptogenic outcome and granule cell pathology in patients with MTS has been observed, thus suggesting that dentate gyrus alterations may play a role in drug-resistant TLE.

SCARB2 mutations in progressive myoclonus epilepsy (PME) without renal failure.

OBJECTIVE: Mutations in SCARB2 were recently described as causing action myoclonus renal failure syndrome (AMRF). We hypothesized that mutations in SCARB2 might account for unsolved cases of progressive myoclonus epilepsy (PME) without renal impairment, especially those resembling Unverricht-Lundborg disease (ULD). Additionally, we searched for mutations in the PRICKLE1 gene, newly recognized as a cause of PME mimicking ULD. METHODS: We reviewed cases of PME referred for diagnosis over two decades in which a molecular diagnosis had not been reached. Patients were classified according to age of onset, clinical pattern, and associated neurological signs into "ULD-like" and "not ULD-like." After exclusion of mutations in cystatin B (CSTB), DNA was examined for sequence variation in SCARB2 and PRICKLE1. RESULTS: Of 71 cases evaluated, 41 were "ULD-like" and five had SCARB2 mutations. None of 30 "not ULD-like" cases were positive. The five patients with SCARB2 mutations had onset between 14 and 26 years of age, with no evidence of renal failure during 5.5 to 15 years of follow-up; four were followed until death. One living patient had slight proteinuria. A subset of 25 cases were sequenced for PRICKLE1 and no mutations were found. INTERPRETATION: Mutations in SCARB2 are an important cause of hitherto unsolved cases of PME resembling ULD at onset. SCARB2 should be evaluated even in the absence of renal involvement. Onset is in teenage or young adult life. Molecular diagnosis is important for counseling the patient and family, particularly as the prognosis is worse than classical ULD.

Neuroethological approach to frontolimbic epileptic seizures and parasomnias: The same central pattern generators for the same behaviours.

The aim of this report is not to make a differential diagnosis between epileptic nocturnal seizures and non-epileptic sleep-related movement disorders, or parasomnias. On the contrary, our goal is to emphasize the commonly shared semiological features of some epileptic seizures and parasomnias. Such similar features might be explained by the activation of the same neuronal networks (so-called 'central pattern generators' or CPG). These produce the stereotypical rhythmic motor sequences - in other words, behaviours - that are adaptive and species-specific (such as eating/alimentary, attractive/aversive, locomotor and nesting habits). CPG are located at the subcortical level (mainly in the brain stem and spinal cord) and, in humans, are under the control of the phylogenetically more recent neomammalian neocortical structures, according to a simplified Jacksonian model. Based on video-polygraphic recordings of sleep-related epileptic seizures and non-epileptic events (parasomnias), we have documented how a transient "neomammalian brain" dysfunction - whether epileptic or not - can 'release' (disinhibition?) the CPG responsible for involuntary motor behaviours. Thus, in both epileptic seizures and parasomnias, we can observe: (a) oroalimentary automatisms, bruxism and biting; (b) ambulatory behaviours, ranging from the classical bimanual-bipedal activity of 'frontal' hypermotor seizures, epileptic and non-epileptic wanderings, and somnambulism to periodic leg movements (PLM), alternating leg muscle activation (ALMA) and restless legs syndrome (RLS); and (c) various sleep-related events such as ictal fear, sleep terrors, nightmares and violent behaviour.

Negative myoclonus. An overview of its clinical features, pathophysiological mechanisms, and management.

Negative myoclonus (NM) is an unspecific motor disorder that can characterize a variety of neurological conditions. From the clinical point of view, NM appears as a shock-like involuntary jerky movement caused by a sudden, brief interruption of muscle activity. Asterixis is a type of NM that occurs typically in toxic-metabolic encephalopathies. NM of epileptic nature, or epileptic negative myoclonus (ENM), is defined as an interruption of tonic muscle activity, which is time-locked to an epileptic EEG abnormality, without evidence of an antecedent positive myoclonia in the agonist-antagonist muscles. ENM can be observed in idiopathic, cryptogenic, and symptomatic epileptic disorders. Pathophysiological hypotheses on the origin of NM involve subcortical as well as cortical mechanisms. Recent neuroimaging and neurophysiologic investigations, including intracerebral recordings and electrical stimulation procedures in epileptic patients, suggest the participation of premotor, primary motor, primary sensory, and supplementary motor areas in the genesis of NM. Polygraphic monitoring is essential for the diagnosis of NM, allowing the demonstration of brief interruptions of a tonic EMG activity, not preceded by a positive myoclonus in the agonist and antagonist muscles of the affected limb. Simultaneous EEG-EMG monitoring demonstrating the association of NM with an epileptic potential is consistent with the diagnosis of ENM. Evolution and prognosis of NM is mainly related to aetiology. In childhood idiopathic partial epilepsy, ENM can respond to some drugs (in particular, ethosuximide), whereas other medications (such as carbamazepine or phenytoin) have been reported to induce or worsen it.

Central pattern generators for a common semiology in fronto-limbic seizures and in parasomnias. A neuroethologic approach.

Central pattern generators (CPGs) are genetically determined neuronal aggregates in the mesencephalon, pons and spinal cord subserving innate motor behaviours essential for survival (feeding, locomotion, reproduction etc.). In higher primates CPGs are largely under neocortical control. We describe how certain motor events observed in parasomnias and epileptic seizures could have similar features and resemble motor behaviours, which can be the expression of the same CPG. Both epilepsy and sleep can lead to a temporary loss of control of neomammalian cortex that facilitates through a common platform (arousal) the emergences of stereotyped inborn fixed action patterns. Therefore we suggest that, independently from the nature of the trigger, be it a seizure or a parasomnia, the same CPGs can be involved, "caught up", leading to a common motor semiology (the "Carillon theory").

Rhythmic teeth grinding induced by temporal lobe seizures.

The authors report the clinical and polygraphic features of rhythmic teeth grinding observed in a patient as the predominant symptom related to temporal lobe seizures during sleep and wakefulness. This observation demonstrates that exceptionally a teeth-grinding event can be not only a parasomnia (sleep bruxism) but also an epileptic-related motor event. Electromyographic and autonomic features of seizure-related teeth grinding support the interpretation of this motor phenomenon as a particular form of masticatory activity.

Clinical features and long term outcome of epilepsy in periventricular nodular heterotopia. Simple compared with plus forms.

OBJECTIVES: Little is known about the long term outcome of patients with periventricular nodular heterotopia (PNH) and epilepsy, particularly the course of seizures. This study investigated the electroclinical and prognostic features of 16 patients with PNH. METHODS: Of 120 patients with epilepsy and malformations of cortical development, 16 had PNH. Of these, eight patients had periventricular nodules only (simple PNH) and eight also presented with other cortical or cerebral malformations (subcortical heterotopia; polymicrogyria; focal dysplasia; schizencephaly; cortical infolding; agenesis of the corpus callosum; mega cisterna magna and cerebellar atrophy) (PNH plus). All patients underwent clinical, neurophysiological, and MRI investigation. The mean follow up was 17.3 years (2-40 years). RESULTS: Two electroclinical patterns emerged: (1) The first pattern, associated with simple PNH, was characterised by normal intelligence and seizures, usually partial, which began during the second decade of life. The seizures never became frequent and tended to disappear or become very rare. The EEG showed focal abnormalities. (2) The second pattern, associated with PNH plus, was characterised by mental retardation and seizures that began during the first decade of life. The seizures were very frequent in most cases and sudden drops were observed in six patients. Seizures were medically refractory in four patients. The EEG showed focal and bisynchronous abnormalities. CONCLUSIONS: Two groups of PNH patients with different electroclinical and neuroradiological features can be identified after a long term follow up. The presence of other types of cortical or cerebral malformations, in addition to periventricular nodules, determines a poor prognosis.

A wavelet based analysis of energy redistribution in scalp EEG during epileptic seizures.

In this work, wavelet decomposition and multiresolution analysis are used to explore the changes in scalp EEG signals during epileptic seizures. EEG tracings, which include non-epileptic periods, the beginning of seizure and the peak of seizure, have been decomposed in five details using order 10 Daubechies orthonormal wavelets. Energy has then been computed, at each detail, from square wavelet coefficients, in order to unmask the presence of brief episodes of energy relocation among different scales. Results reveal the existence of significant changes in energy distribution at seizure onset; this redistribution, however, exhibits significant differences from one patient to another, and also among different channels in the same patient. Some channels exhibit a significant energy increase at low scales (high frequencies greater than 20 Hz) at seizure onset, whereas energy drops at higher scales. Other channels, however, exhibit energy increase at high scales (frequency less than 15 Hz) revealing a predominance of low-frequency activity. These two patterns may be simultaneously present at seizure onset and may change with different spatial evolution during the subsequent seizure progression. Wavelet analysis appears as a powerful tool for extracting features relative to seizure, and to study their propagation among different regions in the scalp.

Impaired facial emotion recognition in early-onset right mesial temporal lobe epilepsy.

BACKGROUND: Anteromedial temporal lobe regions, particularly the amygdala, participate in the recognition of emotions from facial expressions. The authors studied the ability of facial emotion recognition (ER) in subjects with symptomatic epilepsy, evaluating whether mesial temporal lobe damage is related to an impairment in the recognition of specific emotions and whether the onset of seizures in a critical period of life could prevent the development of ER. METHODS: Groups included patients with temporal lobe epilepsy (TLE) with MRI evidence of mesial temporal sclerosis (MTS) (n = 33); patients with TLE with MRI evidence of temporal lobe lesions other than MTS (n = 30); and patients with extratemporal epilepsy (n = 33). Healthy volunteers (n = 50) served as controls. ER was tested by matching a facial expression with the name of one of the following basic emotions: happiness, sadness, fear, disgust, and anger. A face-matching task was used to control visuoperceptual abilities with face stimuli. RESULTS: No subject showed deficits in the face-matching task. ER was impaired in patients with right MTS, especially for fearful faces. Patients presenting left MTS, right or left temporal lobe lesions other than MTS, or extratemporal seizure foci showed ER performances similar to controls. In all subjects with right TLE, the degree of emotion recognition impairment was related to age at first seizure (febrile or afebrile) and age at epilepsy onset. CONCLUSIONS: Early-onset right-sided mesial temporal lobe epilepsy is the key substrate determining a severe deficit in recognizing emotional facial expressions, especially fear.

Early ictal speech and motor inhibition in fronto-mesial epileptic seizures: a polygraphic study in one patient.

OBJECTIVE: To investigate ictal motor inhibition occurring during seizures in a patient with a tumor located in the left fronto-mesial pre-central cortex. METHODS: Awake and sleep video-polygraphic monitoring, recording scalp EEG and EMG activities from several cranial, trunk and limbs muscles, was performed in a patient with drug-resistant recurrent focal motor seizures before surgical treatment. Speech/motor tasks were repeatedly administered to the patient during the recording sessions in order to evaluate the occurrence of early ictal motor inhibition. RESULTS: Thirty-four seizures were recorded during wakefulness showing a stereotyped pattern of inhibition of speech and voluntary movements followed by sequential activation of upper limb-trunk-lower limb muscles contralateral to the tumor. Polygraphic recordings showed that: (1) initial speech and motor arrest were associated with the EMG evidence of progressive muscle tone suppression in cranial and right distal upper limb muscles; (2) tonic contraction of right deltoid, biceps brachii, intercostalis and paraspinalis muscles appeared after motor inhibition; (3) tonic-clonic activity in the right tibialis anterior muscle occurred at the end of seizures. Eleven subclinical seizures were recorded during sleep showing mild focal tonic EMG activity in right side trunk muscles. CONCLUSIONS: Our findings evidenced early and somatotopically organized inhibition of voluntary movement at the beginning of epileptic seizures with fronto-mesial onset. The demonstration that speech and motor arrest were associated with progressive EMG suppression in cranial and limb muscles supports the hypothesis of motor inhibitory seizures originating in the mesial aspect of pre-motor frontal cortex.

Video games are exciting: a European study of video game-induced seizures and epilepsy.

BACKGROUND: Video game seizures have been reported in photosensitive and non-photosensitive patients with epilepsy. The game Super Mario World, has led to many cases of first seizures. We examined whether this game was indeed more provocative than other programs and whether playing the game added to this effect. METHODS: We prospectively investigated 352 patients in four European cities, using a standard protocol including testing of a variety of visual stimuli. We correlated historical data on provocative factors in daily life with electroencephalographic laboratory findings. RESULTS: The video game, Super Mario World proved more epileptogenic than standard TV programs and as provocative as programs with flashing lights and patterns. Most striking was the fact that video game-viewing and-playing on the 50 and 100 Hz TV was significantly more provocative than viewing the standard program (P < 0.001, P < 0.05 respectively). Playing the video game Mario World on a 50 Hz TV, appeared to be significantly more provocative than playing this game on the 100 Hz TV (P < 0.001). Of 163 patients with a history of TV-, VG- or CG-seizures, 85% of them showed epileptiform discharges in response to photic stimulation, 44% to patterns, 59% to 50 Hz TV and 29% to 100 Hz TV. CONCLUSIONS: Children and adolescents with a history of video game seizures are, in the vast majority, photosensitive and should be investigated with standardised photic stimulation. Games and programs with bright background or flashing images are specifically provocative. Playing a video game on a 100 Hz TV is less provocative [published with videosequences].