Perceived self-control of seizures in patients with uncontrolled partial epilepsy

Somatosensory Auras in Epilepsy: A Narrative Review of the Literature

An aura is a subjective experience felt in the initial phase of a seizure. Studying auras is relevant as they can be warning signs for people with epilepsy. The incidence of aura tends to be underestimated due to misdiagnosis or underrecognition by patients unless it progresses to motor features. Also, auras are associated with seizure remission after epilepsy surgery and are an important prognostic factor, guiding the resection site and improving surgical outcomes. Somatosensory auras (SSAs) are characterized by abnormal sensations on one or more body parts that may spread to other parts following a somatotopic pattern. The occurrence of SSAs among individuals with epilepsy can range from 1.42% to 80%. The upper extremities are more commonly affected in SSAs, followed by the lower extremities and the face. The most common type of somatosensory aura is paresthetic, followed by painful and thermal auras. In the primary somatosensory auras, sensations occur more commonly contralaterally, while the secondary somatosensory auras can be ipsilateral or bilateral. Despite the high localizing features of somatosensory areas, cortical stimulation studies have shown overlapping sensations originating in the insula and the supplementary sensorimotor area.

Epileptic Prodromes: Insights from Surveying 196 Patients and 150 Caregivers

OBJECTIVE

Uncontrolled epilepsy creates a constant source of worry for patients and puts them at a high risk of injury. Identifying recurrent "premonitory" symptoms of seizures and using them to recalibrate seizure prediction algorithms may improve prediction performances. This study aimed to investigate patients' ability to predict oncoming seizures based on preictal symptoms.

METHODS

Through an online survey, demographics and clinical characteristics (e.g., seizure frequency, epilepsy duration, and postictal symptom duration) were collected from people with epilepsy and caregivers across Canada. Respondents were asked to answer questions regarding their ability to predict seizures through warning symptoms. A total of 196 patients and 150 caregivers were included and were separated into three groups: those who reported warning symptoms within the 5 minutes preceding a seizure, prodromes (symptoms earlier than 5 minutes before seizure), and no warning symptoms.

RESULTS

Overall, 12.2% of patients and 12.0% of caregivers reported predictive prodromes ranging from 5 minutes to more than 24 hours before the seizures (median of 2 hours). The most common were dizziness/vertigo (28%), mood changes (26%), and cognitive changes (21%). Statistical testing showed that respondents who reported prodromes also reported significantly longer postictal recovery periods compared to those who did not report predictive prodromes (P < 0.05).

CONCLUSION

Findings suggest that patients who present predictive seizure prodromes may be characterized by longer patient-reported postictal recovery periods. Studying the correlation between seizure severity and predictability and investigating the electrical activity underlying prodromes may improve our understanding of preictal mechanisms and ability to predict seizures.

Epilepsy, identity, and the experience of the body

Living with a chronic condition can challenge a person's identity, yet there is a paucity of research exploring this experience for people with epilepsy and particularly for those diagnosed in adulthood. Consequently, through an interpretative phenomenological approach, the current study aimed to explore what the experience of adult-onset epilepsy meant for a person's identity. Thirty-nine people with adult-onset epilepsy from across the UK took part in up to two semi-structured interviews. A modified form of interpretative phenomenological analysis was conducted and identified three themes: 1) disarming the impact of seizures considered strategies used to control seizure occurrence and regain a sense of control over the body; 2) distinguishing the self from the body highlighted participants' attempts to separate their sense of self from the unpredictability of their bodies; 3) separating epilepsy from themselves demonstrated how participants externalized epilepsy from themselves in order to reject it as part of their identity. The findings highlighted that living with adult-onset epilepsy can challenge a person's sense of self and trust in their body, resulting in the adoption of various strategies to manage the threat to their identity. As such, practitioners must pay attention to the impact that adult-onset epilepsy can have on a person's identity and faith in their body.

Prodrome in epilepsy

BACKGROUND

Prodromal symptoms (PS) of epileptic seizures are clinically well-recognized but relatively little researched. The purpose of this review was to examine the evidence in the literature for the existence of prodrome and the reported frequency and nature of prodromal characteristics.

METHODS

We performed a PubMed review of the clinical characteristics, frequency, and duration of PS in papers published between 2007 and 2017. We also reviewed findings from prospective studies into the predictive performance of prodrome. In a second analysis, we reviewed studies reporting a single symptom/sign of prodrome.

RESULTS

In 8 studies reporting on the prevalence of prodrome, we found a mean frequency of 21.9%. The most frequent symptoms were "funny feeling" (10.4%), confusion (9.0%), anxiety (8.6%), and irritability (7.7%), but other features were also reported. The duration of prodrome was typically between 10min and 3days, with most prodromes lasting for between 30min and 24h. In studies that reported a single prodromal symptom/sign, headache was the most frequent: 8% with a range of between 1.2 and 30%.

CONCLUSIONS

Prodromes are characterized by a broad spectrum of preictal symptoms that may be experienced for a duration of between 10min and several days, which usually persist until seizure onset. Opinion is divided on their precise nature and value as predictors of seizures. A greater understanding of prodromes might offer insights into the preictal period and hold promise for new seizure management therapies.

Self-control of epileptic seizures by nonpharmacological strategies

Despite the unpredictability of epileptic seizures, many patients report that they can anticipate seizure occurrence. Using certain alert symptoms (i.e., auras, prodromes, precipitant factors), patients can adopt behaviors to avoid injury during and after the seizure or may implement spontaneous cognitive and emotional strategies to try to control the seizure itself. From the patient's view point, potential means of enhancing seizure prediction and developing seizure control supports are seen as very important issues, especially when the epilepsy is drug-resistant. In this review, we first describe how some patients anticipate their seizures and whether this is effective in terms of seizure prediction. Secondly, we examine how these anticipatory elements might help patients to prevent or control their seizures and how the patient's neuropsychological profile, specifically parameters of perceived self-control (PSC) and locus of control (LOC), might impact these strategies and quality of life (QOL). Thirdly, we review the external supports that can help patients to better predict seizures. Finally, we look at nonpharmacological means of increasing perceived self-control and achieving potential reduction of seizure frequency (i.e., stress-based and arousal-based strategies). In the past few years, various approaches for detection and control of seizures have gained greater interest, but more research is needed to confirm a positive effect on seizure frequency as well as on QOL.

Modeling seizure self-prediction: an e-diary study

PURPOSE

A subset of patients with epilepsy successfully self-predicted seizures in a paper diary study. We conducted an e-diary study to ensure that prediction precedes seizures, and to characterize the prodromal features and time windows that underlie self-prediction.

METHODS

Subjects 18 or older with localization-related epilepsy (LRE) and ≥3 seizures per month maintained an e-diary, reporting a.m./p.m. data daily, including mood, premonitory symptoms, and all seizures. Self-prediction was rated by, "How likely are you to experience a seizure (time frame)?" Five choices ranged from almost certain (>95% chance) to very unlikely. Relative odds of seizure (odds ratio, OR) within time frames was examined using Poisson models with log normal random effects to adjust for multiple observations.

KEY FINDINGS

Nineteen subjects reported 244 eligible seizures. OR for prediction choices within 6 h was as high as 9.31 (CI 1.92-45.23) for "almost certain." Prediction was most robust within 6 h of diary entry, and remained significant up to 12 h. For nine best predictors, average sensitivity was 50%. Older age contributed to successful self-prediction, and self-prediction appeared to be driven by mood and premonitory symptoms. In multivariate modeling of seizure occurrence, self-prediction (2.84; CI 1.68-4.81), favorable change in mood (0.82; CI 0.67-0.99), and number of premonitory symptoms (1.11; CI 1.00-1.24) were significant.

SIGNIFICANCE

Some persons with epilepsy can self-predict seizures. In these individuals, the odds of a seizure following a positive prediction are high. Predictions were robust, not attributable to recall bias, and were related to self-awareness of mood and premonitory features. The 6-h prediction window is suitable for the development of preemptive therapy.

Ezogabine (KCNQ2/3 channel opener) prevents delayed activation of meningeal nociceptors if given before but not after the occurrence of cortical spreading depression

We proposed recently that induction of delayed activation of trigeminovascular neurons by cortical spreading depression (CSD) can explain the delayed onset of headache after the migraine aura ("aura"). This prompted us to search for ways to block the neuronal activation by CSD - a preclinical correlate of an attempt to find a drug that can block the initiation of headache when administered shortly after onset of aura (i.e., preemptively). Because migraine headache and epileptic seizures are comorbid chronic neurological disorders characterized by hyperexcitable brain networks, we began the search for such goal with an M-type potassium channel opener. We opted to use ezogabine, recently approved by the FDA as adjunctive treatment of partial onset seizures in adults, because it is a selective KCNQ2/3 channel opener. When CSD was induced before ezogabine injection (8.25 mg/kg, i.p.), 40% (6/15) of the units doubled their firing rate about 45 min later for about 95 min. Similarly, when CSD was induced before vehicle was injected (4% DMSO, 0.5% methylcellulose), 50% (3/6) of the units doubled their firing rate about 30 min later for about 120 min. When CSD was triggered 1h after ezogabine injection, it activated only 8% of the units. By itself, ezogabine injection resulted in a 30% attenuation of ongoing firing in all 10 control units. Thus, activation of KCNQ2/3 channels during the aura is unlikely to preempt the onset of headache but may reduce the incidence of migraine if given during prodromes that precede the headache by hours. Given the mechanistic similarities between migraine aura and epileptic seizures, it may be worthwhile to determine whether preemptive administration of ezogabine can prevent oncoming seizures in patients whose warning signs precede their seizures by more than an hour.

Epileptic prodromes: are they nonconvulsive status epilepticus?

PURPOSE

The aim of this study was to assess how frequently prodromes occur in an adult patient group from a tertiary referral epilepsy centre and to investigate the EEG changes during the prodromes.

METHODS

578 consecutive patients were interviewed on subjective phenomena, experiences heralding the seizures, for at least 30min before the start of the seizure. EEGs were recorded during the prodromes.

RESULTS

Ten out of 490 included patients had prodromes (2%). We were able to record EEG during prodromes in 6 patients. Three patients had EEG changes corresponding to nonconvulsive status epilepticus. Three patients had unrevealing EEG recordings during prodromes.

CONCLUSION

Our results suggest that at least in a part of the patients, the prodromes are actually ictal phenomena, and should be treated as nonconvulsive status epilepticus.

Trigger self-control and seizure arrest in the Andrews/Reiter behavioral approach to epilepsy: a retrospective analysis of seizure frequency

The aim of this retrospective study is to describe changes of seizure frequency in epilepsy patients who participated in the Andrews/Reiter behavioral intervention for epilepsy. For this uncontrolled retrospective study, data were extracted from patients' medical journals. Intention-to-treat-analyses were restricted to patients with sufficient documentation supporting a diagnosis of probable or definite epilepsy. Main outcome variable was a comparison of mean seizure frequency at baseline and toward completion of the program. The seizure frequency of 30 (50%) patients showed a clinically meaningful improvement (>50% reduction of seizures) toward the end of the intervention. Twenty-two (37%) patients became seizure-free at the end of the intervention. In summary, a clinically meaningful reduction in reported seizure frequency was observed in epilepsy patients who received the Andrews/Reiter intervention for epilepsy. Prospective trials are needed to further investigate the program's efficacy and to study epileptic seizure triggers.

Seizure prediction and recall

Using separate generalized mixed-effects models, we assessed seizure recall and prediction, as well as contributing diagnostic variables, in 83 adult patients with epilepsy undergoing video/EEG monitoring. The model revealed that when participants predicted a seizure, probability equaled 0.320 (95% CI: 0.149-0.558), a significant (P<0.05) increase over negative predictions (0.151, 95% CI: 0.71-0.228]). With no seizure, the rate of remembering was approximately 0.130 (95% CI: 0.73-0.219), increasing significantly to 0.628 (95% CI: 0.439 to 0.784) when a seizure occurred (P<0.001). Of the variables analyzed, only inpatient seizure rate influenced predictability (P<0.001) or recollection (P<0.001). These models reveal that patients were highly aware of their seizures, and in many cases, were able to make accurate predictions, for which seizure rate may be an important factor.

Triggers and techniques in termination of partial seizures

OBJECTIVE

Growing interest in seizure prediction exists as a means to deliver newer antiepileptic therapies, though patient self-termination of seizures has received little attention.

METHODS

Two hundred twenty-three patients able to recognize seizure onset were surveyed in an outpatient epilepsy clinic. A seven-question survey administered prospectively assessed self-reported seizure prediction and clinical techniques used for self-termination. Survey responses targeted percentage predictability of seizures, timing of clinical prediction, likelihood/timing of termination, frequency and effectiveness of methods used, and perspectives of patient and physician belief in self-termination.

RESULTS

Two hundred twenty-three patients (89 males) with a mean age of 42.7 years, average duration of epilepsy of 20.8 years and monthly mean seizure frequency of 4.1 comprised the study group. Thirty-eight percent completed >75% of the survey. Prior treatment included a mean of 6.0 AEDs (40/192 had surgery); 65% had ongoing seizures. Sixty percent of 223 patients reported a history of an aura, and 39% consistently noted auras for >75% of their current seizures. Of the patients with auras, seizure triggers were reported in 74%, with worry and stress (N=69), sleep deprivation (N=60), and missed medication (N=56) most frequently cited. Seventeen percent were positive/somewhat sure they could predict onset, with approximately 20% noting rapid onset in <15 seconds. Twenty-two of 82 noted that they had some ability to self-terminate their seizures, and 9% were positive that they could do so. Methods to self-terminate were effective (>75% certainty) in 35% (26/75). The primary methods were lying down/resting and taking extra medication.

CONCLUSION

The majority of patients with partial seizures recognize triggers of seizure onset. In addition, more than one-third believe they can effectively self-terminate their partial-onset seizures. Lying down, resting, and taking extra medication were the most common techniques instituted by patients. Correlating clinical symptoms at seizure onset with termination may help improve the sensitivity in seizure prediction.

Initial symptoms, precipitant factors, and techniques to control epileptic seizures: the carer's perspective

Subjective experiences of seizures and events that occur prior to seizures may be useful in assisting health professionals to devise treatment plans tailored to the individual. The aim of this study was to investigate carers' knowledge of their patients' preseizure activity. Of 240 questionnaires mailed out to registrants on an epilepsy research database, 78 were anonymously returned (32.5%). Participants were aged between 18 and 89, with a mean age of 50.94 years (SD=17.23), and 82.1% were female. Of 78 participants, 74.4% reported that their patients experienced at least one symptom prior to a seizure, 88.5% reported that their patients experienced at least one seizure as a result of a specific event, and 56.4% reported that their patients had tried at least one technique to stop a seizure. The rates reported are comparable to those reported in other studies measuring responses from people with epilepsy.

Age and gender differences in initial symptoms and precipitant factors of epileptic seizures: an Australian study

The aim of this study was to document self-perceived warning signs, initial symptoms, triggers of epileptic seizures, and techniques to control seizures for people with epilepsy and to establish patterns in these self-reported experiences of epilepsy in relation to age and gender. Of 338 questionnaires mailed out to registrants on an epilepsy research database, 225 were anonymously returned (66.6% response rate). The questionnaire contained information regarding demographic characteristics, living with epilepsy, and self-perceived warning signs, initial symptoms, triggers of seizures, and techniques to control seizures. Of 225 participants, 86.6% reported at least one symptom prior to a seizure, and 69.8% indicated that they had tried at least one technique to stop a seizure. Younger participants were more likely to report some of the symptoms, triggers, and techniques, compared with older participants, and there was a gender difference on some of the triggers.

The lived experience of initial symptoms of and factors triggering epileptic seizures

The aim of this study was to document the self-perception of initial symptoms of and factors triggering epileptic seizures in a sample of people with epilepsy (PWE) and their carers. Among 600 participants, questionnaires were returned by 309 (51.5%), of whom 72.8% were PWE and 27.2% were carers and others. Experiencing at least one symptom prior to a seizure was reported by 86.9% of PWE and 74% of carers. The most common symptoms were a funny feeling, confusion, and anxiety. Experiencing one trigger that resulted in a seizure was reported by 89.8% of PWE and 85.5% of carers. The most common triggers were tiredness, stress, and sleep deprivation. Among PWE and their carers, 63.6% and 51.3%, respectively, indicated that they can tell when a seizure is about to occur, and 26.7% and 15.4%, respectively, indicated that they felt they could stop a seizure. The most common techniques were resting, medication, and relaxation.

Early follow-up data from seizure diaries can be used to predict subsequent seizures in same cohort by borrowing strength across participants

Accurate prediction of seizures in persons with epilepsy offers opportunities for both precautionary measures and preemptive treatment. Previously identified predictors of seizures include patient-reported seizure anticipation, as well as stress, anxiety, and decreased sleep. In this study, we developed three models using 30 days of nightly seizure diary data in a cohort of 71 individuals with a history of uncontrolled seizures to predict subsequent seizures in the same cohort over a 30-day follow-up period. The best model combined the individual's seizure history with that of the remainder of the cohort, resulting in 72% sensitivity for 80% specificity, and 0.83 area under the receiver operating characteristic curve. The possibility of clinically relevant prediction should be examined through electronic data capture and more specific and more frequent sampling, and with patient training to improve prediction.

Seizure anticipation: are neurophenomenological approaches able to detect preictal symptoms?

Analysis of electroencephalographic signals and several brain imaging studies suggest that a preictal state precedes the onset of seizures. In this study, we used phenomenological strategies to detect modifications in patients' experience before their seizures. We observed that patients with partial epilepsy feeling an aura (n=9) frequently experienced prodromes (n=6). Prodromes were subtle preictal symptoms, varying among patients and having common negative features. They were generally continuous before seizures and could last hours, whereas auras were sudden and intermittent. All patients were able to recognize facilitating factors. We also found that patients spontaneously develop cognitive countermeasures to avoid facilitating factors (n=6), to prevent a seizure (n=1) or to interrupt a seizure (n=5). Prodromes are not specific enough for clinical use, but could refine the behavioral strategies used in the treatment of epilepsy and the pathophysiology of the preictal state.

Affect in patients with epilepsy undergoing video/EEG monitoring: retrospective versus momentary assessment and temporal relationship to seizures

This study was designed to (1) compare retrospective and momentary assessments of mood/affect, and (2) examine the temporal relationship between affect and seizure occurrence. Patients with epilepsy undergoing long-term video/EEG monitoring (LTM) completed an affect rating of how they felt "at that moment" each time a programmed watch beeped (momentary assessment); these ratings were averaged across each patient's hospital stay. Prior to discharge, patients were asked to think back and rate how they felt "during their hospital stay" using the same rating scale (retrospective assessment). Results indicated that patients retrospectively recalled feeling significantly more positive during their LTM than they reported feeling when they were actually undergoing LTM. Among patients who had EEG-verified seizures, momentary assessments were used to compare affect during the interictal periods with affect during the prodromal and postictal periods. The latter two periods were characterized by significantly less activated positive affect than were the interictal periods.