From precipitation to inhibition of seizures: rationale of a therapeutic paradigm

Non-invasive sensory neuromodulation in epilepsy: Updates and future perspectives

Epilepsy, one of the most common neurological disorders, often is not well controlled by current pharmacological and surgical treatments. Sensory neuromodulation, including multi-sensory stimulation, auditory stimulation, olfactory stimulation, is a kind of novel noninvasive mind-body intervention and receives continued attention as complementary safe treatment of epilepsy. In this review, we summarize the recent advances of sensory neuromodulation, including enriched environment therapy, music therapy, olfactory therapy, other mind-body interventions, for the treatment of epilepsy based on the evidence from both clinical and preclinical studies. We also discuss their possible anti-epileptic mechanisms on neural circuit level and propose perspectives on possible research directions for future studies.

Seizures as a Struggle between Life and Death: An Existential Approach to the Psychosocial Impact of Seizures in Candidates for Epilepsy Surgery

INTRODUCTION

Mental health comorbidities such as depression and anxiety are common in epilepsy, especially among people with pharmacoresistant epilepsy who are candidates for epilepsy surgery. The Psychology Task Force of the International League Against Epilepsy advised that psychological interventions should be integrated into comprehensive epilepsy care.

METHODS

To better understand the psychological impact of epilepsy and epileptic seizures in epilepsy surgery candidates, we analysed interviews with this subgroup of patients using Karl Jaspers' concept of limit situations, which are characterised by a confrontation with the limits and challenges of life. These are especially chance, randomness, and unpredictability, death and finitude of life, struggle and self-assertion, guilt, failure, and falling short of one's aspirations.

RESULTS

In 43 interviews conducted with 15 people with drug-resistant epilepsy who were candidates for epilepsy surgery, we found that these themes are recurrent and have a large psychosocial impact, which can result in depression and anxiety. For some people, epileptic seizures appear to meet the criteria for traumatic events.

CONCLUSION

Understanding epilepsy and seizures as existential challenges complements the neurobiological explanations for psychological comorbidities and can help tailor psychological interventions to the specific needs of people with epilepsy, especially those who are candidates for surgical treatment.

"What is this strange sensation?" A qualitative exploration of metaphors used to verbalise hard-to-describe experiences by people with epilepsy

Mental health comorbidities are frequent in epilepsy. Consequently, psychotherapy is becoming increasingly important. To address the psychological needs of people with epilepsy (PwE) it is essential to understand the subjective experiences of seizures better. There is little research on how people report seizures, and which psychological representations they have. We conducted a thematic analysis based on 42 (micro-phenomenological) interviews with 15 participants on their experiences of seizures. In these interviews, we identified three categories of seizure descriptions: (1) phenomena related to the body and emotions; (2) the moments that are difficult to describe; and (3) the use of figurative language and metaphors. Paroxysmal physical and psychological sensations were often reported spontaneously by the participants. The moments that were difficult to describe were expressed, among other things, through the use of paradoxes or the report of a 'strange' feeling and led participants to use figurative language. As these metaphors can reveal important information about people's subjective experiences, they were analyzed in detail. We identified the three main types of metaphors that the participants used most frequently: (1) perception, (2) nature, and (3) battle. The theme of battle was most frequently used in different forms and was closely related to the metaphors from the fields of perception and nature, thus representing a key point in the personal experience of seizures. These findings can contribute to developing psychotherapeutic approaches for the treatment of seizure disorders.

Let there be light: Inhibitory effect of photic stimulation on spike frequency in patients with mesial temporal lobe epilepsy with hippocampal sclerosis

Inhibition of epileptic discharges and seizures by sensory stimuli is an interesting phenomenon, but highly understudied. Here, we aimed to investigate the modulation of epileptiform discharges in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) via photic stimulation (PS), based on a hypothesis that light stimulation may activate thalamocortical networks limiting the propagation of interictal epileptiform discharges. In order to do so, all EEGs performed in patients diagnosed with MTLE-HS were reviewed to include available recordings with definite epileptiform abnormalities. These were reevaluated by two clinical neurophysiologists independently, and spikes were counted in a blinded manner to calculate spike index (SI) (spikes per minute-pm) for baseline EEG, hyperventilation (HV), and PS periods. Our final study group consisted of 30 MTLE-HS patients with a mean age of 34.5 (±12.5) years. Mean seizure frequency was 38.1 per year (±46.6), and the mean disease duration was 16.2 years (±12.1). Mean SI during baseline was calculated as 1.17 pm (±1.4), during HV 2.1 pm (±2.8) and during PS 0.8 pm (±2.5). As a result, SI was significantly lower during PS compared to baseline (p = 0.001). Our findings suggest that PS has a remarkable inhibitory effect on epileptiform discharges in MTLE-HS patients, indicating the need for further prospective investigations for clinical translation.

Perceptions of Modulatory Factors in Migraine and Epilepsy: A Multicenter Study

Background: Migraine and epilepsy are both common episodic disorders, typically precipitated or inhibited by some modulatory factors (MFs). Objective: To assess the self-perception of MFs in patients with migraine (PWM) compared to patients with epilepsy (PWE) with a standardized protocol in different countries. Methods: Transcultural multicenter comparative cross-sectional study. All consecutive patients who fulfilled the ICHD-3 criteria for migraine and ILAE's criteria for epilepsy, with at least 1 year of follow-up were interviewed with a semi-structured questionnaire on clinical and epidemiological data and were asked to identify all experienced MFs from a provided list. Results: A total of 608 individuals were surveyed at five university referral centers in Brazil, Guatemala, Lithuania and Turkey. Two hundred and nineteen (91.6%) PWM and 305 (82.7%) PWE identified attack precipitating factors (PFs; p < 0.001). The most frequent three PFs reported by epilepsy patients were: "lack of sleep" (56.6%), "emotional stress" (55.3%), "negative feelings" (53.9%), while among migraine patients "emotional stress" (81.6%), "lack of sleep" (77.8%), "negative feelings" (75.7%) were cited. Inhibitory factors (IFs) for the episodes were reported by 68 (28.5%) PWM and 116 (31.4%) PWE. "Darkness" was the most common one, described by 35.6% of PWM whereas "positive feelings" reported by 10.6% of PWE. Most MFs are concordant across the countries but some transcultural differences were noted. Conclusion: The MFs of migraine and epilepsy attacks and their varying frequencies according to different countries were investigated with the same standardized questionnaire, for the first time. MFs were recognized very often in both migraine and epilepsy cohorts, but in distinct disease-specific prevalence, being more frequent in migraine. Recognition of self-perceived MFs may be helpful for the management of both illnesses.

Location-specific reflex epilepsy: a novel reflex epilepsy phenotype

Reflex epilepsies are rare syndromes where seizures are triggered by particular stimuli or activities that may be motor, sensory or cognitive in nature. Triggers are diverse, may be extrinsic or intrinsic in nature and heterogeneous phenotypes have been described over the years. We give an account of a case of location-specific reflex epilepsy which we suggest is a novel reflex epilepsy phenotype relating to higher cortical function (HCF), and review the literature in relation to features of HCF reflex epilepsies described to date.

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Reflex seizures occur in a range of epilepsy syndromes.

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We describe a novel phenotype of location-specific reflex epilepsy associated with focal electrographic discharges.

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Higher cortical processes relating to being present in a particular location could serve as a trigger in reflex epilepsy.

Intense olfactory stimulation blocks seizures in an experimental model of epilepsy

There are reports of patients whose epileptic seizures are prevented by means of olfactory stimulation. Similar findings were described in animal models of epilepsy, such as the electrical kindling of amygdala, where olfactory stimulation with toluene (TOL) suppressed seizures in most rats, even when the stimuli were 20% above the threshold to evoke seizures in already kindled animals. The Wistar Audiogenic Rat (WAR) strain is a model of tonic-clonic seizures induced by acute acoustic stimulation, although it also expresses limbic seizures when repeated acoustic stimulation occurs - a process known as audiogenic kindling (AK). The aim of this study was to evaluate whether or not the olfactory stimulation with TOL would interfere on the behavioral expression of brainstem (acute) and limbic (chronic) seizures in the WAR strain. For this, animals were exposed to TOL or saline (SAL) and subsequently exposed to acoustic stimulation in two conditions that generated: I) acute audiogenic seizures (only one acoustic stimulus, without previous seizure experience before of the odor test) and II) after AK (20 acoustic stimuli [2 daily] before of the protocol test). We observed a decrease in the seizure severity index of animals exposed only to TOL in both conditions, with TOL presented 20s before the acoustic stimulation in both protocols. These findings were confirmed by behavioral sequential analysis (neuroethology), which clearly indicated an exacerbation of clusters of specific behaviors such as exploration and grooming (self-cleaning), as well as significant decrease in the expression of brainstem and limbic seizures in response to TOL. Thus, these data demonstrate that TOL, a strong olfactory stimulus, has anticonvulsant properties, detected by the decrease of acute and AK seizures in WARs.

Epilepsy and the Sensory Systems

The relations of epilepsy and the sensory systems are bidirectional. Epilepsy may act on sensory systems by producing sensory seizure symptoms, by altering sensory performance, and by epilepsy treatment causing sensory side effects. Sensory system activity may have an important role in both generation and inhibition of seizures.

Olfactory stimulation induces delayed responses in epilepsy

Precipitation and inhibition of seizures and epileptic discharges by sensory stimuli are receiving increasing attention because they provide insight into natural seizure generation in human epilepsies and can identify potential nonpharmacological therapies. We aimed to investigate modulation (provocation or inhibition) of epileptiform discharges (EDs) in mesial temporal lobe epilepsy (MTLE) versus idiopathic generalized epilepsy (IGE) by olfactory stimulation (OS) compared with standard provocation methods. The underlying hypothesis was that any response would be more likely to occur in MTLE, considering the anatomical connections of the temporal lobe to the olfactory system. This multicenter, international study recruited patients with either MTLE or IGE who were systematically compared for responses to OS using an EEG/video-EEG protocol including a 30-min baseline, twice 3-min olfactory stimulation with ylang-ylang, hyperventilation, and intermittent photic stimulation. The 95% confidence interval (CI) for the baseline EDs in each patient was calculated, and modulation was assumed when the number of EDs during any 3-min test period was outside this CI. A total of 134 subjects (55 with MTLE, 53 with IGE, and 26 healthy controls) were included. Epileptiform discharges were inhibited during OS in about half the patients with both MTLE and IGE, whereas following OS, provocation was seen in 29.1% of patients with MTLE and inhibition in 28.3% of patients with IGE. Olfactory stimulation was less provocative than standard activation methods. The frequent subclinical modulation of epileptic activity in both MTLE and IGE is in striking contrast with the rarity of reports of olfactory seizure precipitation and arrest. Inhibition during OS can be explained by nonspecific arousal. The delayed responses seem to be related to processing of olfactory stimuli in the temporal lobe, thalamus, and frontal cortex.

Do reflex seizures and spontaneous seizures form a continuum? - triggering factors and possible common mechanisms

Recent changes in the understanding and classification of reflex seizures have fuelled a debate on triggering mechanisms of seizures and their conceptual organization. Previous studies and patient reports have listed extrinsic and intrinsic triggers, albeit their multifactorial and dynamic nature is poorly understood. This paper aims to review literature on extrinsic and intrinsic seizure triggers and to discuss common mechanisms among them. Among self-reported seizure triggers, emotional stress is most frequently named. Reflex seizures are typically associated with extrinsic sensory triggers; however, intrinsic cognitive or proprioceptive triggers have also been assessed. The identification of a trigger underlying a seizure may be more difficult if it is intrinsic and complex, and if triggering mechanisms are multifactorial. Therefore, since observability of triggers varies and triggers are also found in non-reflex seizures, the present concept of reflex seizures may be questioned. We suggest the possibility of a conceptual continuum between reflex and spontaneous seizures rather than a dichotomy and discuss evidence to the notion that to some extent most seizures might be triggered.

Seizure precipitants (triggering factors) in patients with epilepsy

AIM

adult epilepsy clinic population: (a) to identify the frequency of seizure precipitants (triggering factors) and their relative frequency in those with psychiatric disorders, and in those in remission or with active epilepsy, differences in frequency with regard to gender, seizure duration, number of drugs taken; (b) to determine which precipitants patients most commonly report; and (c) to identify differences in the distribution of precipitants among generalized, temporal, and extratemporal epilepsies.

METHODS

Consecutive patients attending a tertiary-care epilepsy clinic were prospectively and an open personal interview to identify and characterize seizure precipitants. Information about the epilepsy and clinical characteristics of patients was collected during the interview and from medical records.

RESULTS

Of 104 patients, 97% cited at least one precipitant. Stress, sleep deprivation, and fatigue were the most frequently reported precipitants. Patients with psychological comorbidities reported a greater percentage of seizures with seizure precipitants. Patients with idiopathic generalized epilepsy seemed to be more sensitive to seizures during awakening and sleep deprivation, patients with extratemporal epilepsy reported more frequent seizures during sleep. There were no differences in frequency or type of seizure precipitants with regard to gender, seizure duration or frequency, and the number of antiepileptic drugs taken.

CONCLUSION

The findings may have implications for the better management of epilepsy by increasing a focus on nonpharmacological therapy. The implications of the findings for nosology and causation of epilepsy are also briefly discussed.

Hippocampal atrophy and memory dysfunction in patients with juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is a well-defined idiopathic generalized epilepsy (IGE) syndrome, being the most common IGE in adults and accounting for 5-11% of patients with epilepsy. While neuropsychological and neuroimaging studies have discussed the thalamofrontal dysfunction as the major pathophysiologic mechanism of JME, investigation on memory is scarce in patients with JME, with lack of objective assessments addressing common complaints and daily difficulties such as recalling telephone numbers, messages to pass on, and taking antiepileptic drugs regularly. The aim of this study was to objectively assess memory deficits in a group of patients with JME using neuropsychological examination combined with structural MRI of the hippocampi. After informed consent, a cohort of 56 consecutive patients with JME (29 males; mean age ± SD = 26.5 ± 9.01 years; range = 14.0-55.0 years) was included. The control group consisted of 42 healthy volunteers (18 males; mean age ± SD = 31.0 ± 8.54 years; range=20.0-56.0 years) without a family history of neuropsychiatric disorders. Patients and controls were submitted to a MRI and to a neuropsychological assessment, and comparisons between groups were performed, as well as a correlation study between hippocampal atrophy and neuropsychological performance in a group of patients with JME. The level of statistical significance was set at p<0.05. Significant hippocampal atrophy among patients with JME was observed, which was correlated with memory dysfunctions. The present findings reinforce the existence of functional-anatomic ictogenic networks that are not limited to frontal lobes, providing further support towards the concept of 'system epilepsies' in JME.

Prodromal symptoms in epileptic patients: clinical characterization of the pre-ictal phase

Although recent advances in seizure anticipation have been achieved with the development of several biomathematical electroencephalographic (EEG) methods, pre-ictal clinical phenomena have not been extensively investigated. The aim of the study was to thoroughly analyze premonitory or prodromal symptoms (PS) in a randomly selected sample of 100 adult epileptic patients. A semi-structured protocol was used for in-person interviews to both patients and observers. PS were found in 39% of patients, the most frequent ones being behavioral, cognitive and mood changes. Both patients with focal and generalized epilepsies reported prodromes, although they were more frequently found in the former group. PS were mostly perceived preceding complex partial and generalized tonic-clonic seizures. Prodromal symptoms were reported to have an insidious onset and their duration ranged from 30min to several hours. The potential value of prodromes in seizure anticipation would allow the use of preventive and therapeutic measures, including drugs, neurostimulation procedures and behavioral intervention.

Acceptance and Commitment Therapy and yoga for drug-refractory epilepsy: a randomized controlled trial

OBJECTIVE

There is a need for controlled outcome studies on behavioral treatment of epilepsy. The purpose of this study was to evaluate Acceptance and Commitment Therapy (ACT) and yoga in the treatment of epilepsy.

METHODS

The design consisted of a randomized controlled trial with repeated measures (N=18). All participants had an EEG-verified epilepsy diagnosis with drug-refractory seizures. Participants were randomized into one of two groups: ACT or yoga. Therapeutic effects were measured using seizure index (frequency x duration) and quality of life (Satisfaction with Life Scale, WHOQOL-BREF). The treatment protocols consisted of 12 hours of professional therapy distributed in two individual sessions, two group sessions during a 5-week period, and booster sessions at 6 and 12 months posttreatment. Seizure index was continuously assessed during the 3-month baseline and 12-month follow-up. Quality of life was measured after treatment and at the 6-month and 1-year follow-ups.

RESULTS

The results indicate that both ACT and yoga significantly reduce seizure index and increase quality of life over time. ACT reduced seizure index significantly more as compared with yoga. Participants in both the ACT and yoga groups improved their quality of life significantly as measured by one of two quality-of-life instruments. The ACT group increased their quality of life significantly as compared with the yoga group as measured by the WHOQOL-BREF, and the yoga group increased their quality of life significantly as compared with the ACT group as measured by the SWLS.

CONCLUSIONS

The results of this study suggest that complementary treatments, such as ACT and yoga, decrease seizure index and increase quality of life.