Developmental and epileptic encephalopathies (DEEs) are among the most challenging of all epilepsies to manage, given the exceedingly frequent and often severe seizure types, pharmacoresistance to ...conventional antiseizure medications, and numerous comorbidities. During the past decade, efforts have focused on development of new treatment options for DEEs, with several recently approved in the United States or Europe, including cannabidiol as an orphan drug in Dravet and Lennox–Gastaut syndromes and everolimus as a possible antiepileptogenic and precision drug for tuberous sclerosis complex, with its impact on the mammalian target of rapamycin pathway. Furthermore, fenfluramine, an old drug, was repurposed as a novel therapy in the treatment of Dravet syndrome. The evolution of new insights into pathophysiological processes of various DEEs provides possibilities to investigate novel and repurposed drugs and to place them into the context of their role in future management of these patients. The purpose of this review is to provide an overview of these new medical treatment options for the DEEs and to discuss the clinical implications of these results for improved treatment.
Gamma oscillations and photosensitive epilepsy Hermes, Dora; Kasteleijn-Nolst Trenité, Dorothée G.A.; Winawer, Jonathan
Current biology,
05/2017, Letnik:
27, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Certain visual images, even in the absence of motion or flicker, can trigger seizures in patients with photosensitive epilepsy. As of yet, there is no systematic explanation as to why some static ...images are likely to provoke seizures, while others pose little or no risk. Here, we examined the neurophysiology literature to assess whether the pattern of neural responses in healthy visual cortex is predictive of the pathological responses in photosensitive epilepsy. Previous studies have suggested that gamma oscillations (30–80 Hz) measured in human visual cortex may play a role in seizure generation 1,2. Recently, we and others have shown that increases in gamma band power can come from two very different cortical signals, one that is oscillatory (with a narrow peak between 30 Hz and 80 Hz), and another that is broadband3. The oscillatory signal arises from neuronal synchrony in the local population, while the broadband signal reflects the level of asynchronous neuronal activity, and is correlated with multiunit spiking 4. These two responses have different biological origins and different selectivity for image properties. Here, we followed up on the previous proposals 1,2 to ask whether the image features that increase seizure likelihood in photosensitive epilepsy are linked to narrowband gamma oscillations specifically, or are associated with any kind of increase in visual activity. Based on published work, we compared pairs of image classes on a number of dimensions, and show that the type of image that elicits larger narrowband gamma oscillations in healthy visual cortex is also more likely to provoke seizures or pre-seizure activity in patients with photosensitive epilepsy. In contrast, images that elicit larger broadband, multiunit, or fMRI responses are much less predictive of seizure activity. We propose that a risk factor for seizures in patients with photosensitive epilepsy is engagement of the circuitry that produces gamma oscillations.
Hermes et al. show that the same visual stimuli that induce photosensitive epilepsy also elicit gamma oscillations in the visual cortex, suggesting a possible functional connection.
The objective of this study was to determine areas of consensus among an international panel of experts for the clinical presentation and diagnosis of epilepsy with eyelid myoclonia (EEM; formerly ...known as Jeavons syndrome) to improve a timely diagnosis.
An international steering committee was convened of physicians and patients/caregivers with expertise in EEM. This committee summarized the current literature and identified an international panel of experts (comprising 25 physicians and five patients/caregivers). This international expert panel participated in a modified Delphi process, including three rounds of surveys to determine areas of consensus for the diagnosis of EEM.
There was a strong consensus that EEM is a female predominant generalized epilepsy syndrome with onset between 3 and 12 years of age and that eyelid myoclonia must be present to make the diagnosis. There was a strong consensus that eyelid myoclonia may go unrecognized for years prior to an epilepsy diagnosis. There was consensus that generalized tonic-clonic and absence seizures are typically or occasionally seen in patients. There was a consensus that atonic or focal seizures should lead to the consideration of reclassification or alternate diagnoses. There was a strong consensus that electroencephalography is required, whereas magnetic resonance imaging is not required for diagnosis. There was a strong consensus to perform genetic testing (either epilepsy gene panel or whole exome sequencing) when one or a combination of factors was present: family history of epilepsy, intellectual disability, or drug-resistant epilepsy.
This international expert panel identified multiple areas of consensus regarding the presentation and evaluation of EEM. These areas of consensus may be used to inform clinical practice to shorten the time to the appropriate diagnosis.
There are limited data about the treatment and management of epilepsy with eyelid myoclonia (EEM). The objective of this study was to determine areas of consensus among an international panel of ...experts for the management of EEM (formerly known as Jeavons syndrome).
An international steering committee was convened of physicians and patients/caregivers with expertise in EEM. This committee summarized the current literature and identified an international panel of experts (comprising 25 physicians and five patients/caregivers). This panel participated in a modified Delphi process, including three rounds of surveys to determine areas of consensus for the treatment, other areas of management, and prognosis for EEM.
There was a strong consensus for valproic acid as the first-line treatment, with levetiracetam or lamotrigine as preferable alternatives for women of childbearing age. There was a moderate consensus that ethosuximide and clobazam are also efficacious. There was a strong consensus to avoid sodium channel-blocking medications, except for lamotrigine, as they may worsen seizure control. There was consensus that seizures typically persist into adulthood, with remission occurring in <50% of patients. There was less agreement about other areas of management, including dietary therapy, lens therapy, candidacy for driving, and outcome.
This international expert panel identified multiple areas of consensus regarding the optimal management of EEM. These areas of consensus may inform clinical practice to improve the management of EEM. In addition, multiple areas with less agreement were identified, which highlight topics for further research.
Light flashes, patterns, or color changes can provoke seizures in up to 1 in 4000 persons. Prevalence may be higher because of selection bias. The Epilepsy Foundation reviewed light‐induced seizures ...in 2005. Since then, images on social media, virtual reality, three‐dimensional (3D) movies, and the Internet have proliferated. Hundreds of studies have explored the mechanisms and presentations of photosensitive seizures, justifying an updated review. This literature summary derives from a nonsystematic literature review via PubMed using the terms “photosensitive” and “epilepsy.” The photoparoxysmal response (PPR) is an electroencephalography (EEG) phenomenon, and photosensitive seizures (PS) are seizures provoked by visual stimulation. Photosensitivity is more common in the young and in specific forms of generalized epilepsy. PS can coexist with spontaneous seizures. PS are hereditable and linked to recently identified genes. Brain imaging usually is normal, but special studies imaging white matter tracts demonstrate abnormal connectivity. Occipital cortex and connected regions are hyperexcitable in subjects with light‐provoked seizures. Mechanisms remain unclear. Video games, social media clips, occasional movies, and natural stimuli can provoke PS. Virtual reality and 3D images so far appear benign unless they contain specific provocative content, for example, flashes. Images with flashes brighter than 20 candelas/m2 at 3‐60 (particularly 15‐20) Hz occupying at least 10 to 25% of the visual field are a risk, as are red color flashes or oscillating stripes. Equipment to assay for these characteristics is probably underutilized. Prevention of seizures includes avoiding provocative stimuli, covering one eye, wearing dark glasses, sitting at least two meters from screens, reducing contrast, and taking certain antiseizure drugs. Measurement of PPR suppression in a photosensitivity model can screen putative antiseizure drugs. Some countries regulate media to reduce risk. Visually‐induced seizures remain significant public health hazards so they warrant ongoing scientific and regulatory efforts and public education.
Summary
Eyelid myoclonia with absences (EMA), or Jeavons syndrome, is a generalized epileptic condition clinically characterized by eyelid myoclonia (EM) with or without absences, eye closure‐induced ...electroencephalography (EEG) paroxysms, and photosensitivity; in addition, rare tonic–clonic seizures may also occur. Although first described in 1977 and widely reported by several authors within the last few years, EMA has not been yet recognized as a definite epileptic syndrome. However, when strict criteria are applied to the diagnosis, EMA appears to be a distinctive condition that could be considered a myoclonic epileptic syndrome, with myoclonia limited to the eyelids, rather than an epileptic syndrome with absences.
Epileptic seizures can be provoked by several factors. Better understanding of these factors may improve a patient's sense of control and could reduce seizures. In daily practice, the recognition of ...seizure precipitants relies heavily on clinical or video-EEG evidence, which can be difficult to obtain. Studies of seizure provocation are largely based on selected hospital-based patient populations, which may lead to biased occurrence estimates. Self-reported seizure precipitants are rarely studied, yet are necessary to understand the experiences of patients and improve epilepsy management. We performed a cross-sectional community-based study of 248 epilepsy patients, selected by pharmacy records of anti-epileptic drug use. Self-reported seizure precipitants and potential associated characteristics were assessed using questionnaires. Almost half of all patients (47 %) reported one or more seizure precipitants, of which stress, sleep deprivation, and flickering lights were the most common. In this community-based setting, light-provoked seizures were especially frequent compared to the literature. Idiopathic generalized epilepsy (IGE), a lower age at seizure onset, and having auras or prodromes were found to be important independent prognostic factors associated with provoked seizures. IGE and a younger age at seizure onset have been linked to provoked seizures in earlier reports. The finding of auras or prodromes as a prognostic factor was unexpected, though case reports have described provoked seizures in patients having auras. Assessment of these factors may facilitate the early recognition of seizure precipitants in daily clinical practice. This is important for the optimization of epilepsy management for a large group of patients, as provoked seizures are expected to occur frequently.
Summary
Most patients with epilepsy report that seizures are sometimes, or exclusively, provoked by general internal precipitants (such as stress, fatigue, fever, sleep, and menstrual cycle) and by ...external precipitants (such as excess alcohol, heat, bathing, eating, reading, and flashing lights). Some patients describe very exotic and precise triggers, like tooth brushing or listening to a particular melody. Nevertheless, the most commonly noticed seizure increasers by far are stress, lack of sleep, and fatigue. Recognized reflex seizure triggers are usually sensory and visual, such as television, discotheques, and video games. Visually evoked seizures comprise 5% of the total of 6% reflex seizures. The distinction between provocative and reflex factors and seizures seems artificial, and in many patients, maybe all, there is a combination of these. It seems plausible that all of the above‐mentioned factors can misbalance the actual brain network; at times, accumulation of factors leads then to primary generalized, partial, or secondarily generalized seizures. If the provoking factors are too exotic, patients may be sent to the psychiatrist. Conversely, if the seizure‐provoking fluctuating mechanisms include common habits and environmental factors, these may hardly be considered as provocative factors. Awareness of precipitating factors and its possible interactions might help us to unravel the pathophysiology of epilepsy and to change the notion that seizure occurrence is unpredictable. This article provides an overview of the epidemiology, classification, diagnosis, treatment, and especially similarities in the variety of provocative and reflex factors with resulting general hypotheses.
Summary
Gowers gave migraine a place in the borderland of epilepsy, justified by many relations and the fact that distinction of these two diseases is difficult. Gowers based his ideas on clinical ...histories from his patients, and he concluded that in extremely rare instances one may develop while the other goes on. In modern times, patient testimonies of the problem of differentiating migraine from epilepsy are given in health‐chat Websites. It shows clearly that distinction between the two conditions is still problematic and that migralepsy is either nonexisting or extremely rare as Gowers noticed.
PDF
