Seizures in the elderly: Video/EEG monitoring analysis

EEG and semiology in the elderly: A systematic review

INTRODUCTION

The prevalence and incidence of epileptic seizures and epilepsy increases among the elderly. Epileptic seizures in older people remain often unreported and undiagnosed, contributing to incorrect or delayed treatment. The goal of our review paper is to increase awareness of seizures in the elderly, to improve the diagnostic process in this growing population.

METHODS

We present a systematic review of the literature on EEG findings and seizure semiology among the elderly according to the PRISMA statement. One hundred and two original studies were included and findings were divided in four groups: EEG among elderly without seizures, EEG among elderly with seizures or epilepsy, semiology, and status epilepticus.

CONCLUSIONS

EEG abnormalities are found in approximately half of the geriatric population referred to routine EEG. Slowing (both focal and diffuse) is the most common finding among seniors with and without seizures. Interictal epileptiform discharges (IEDs) are likewise seen among healthy seniors, which reduces their specificity as biomarker for epilepsy. Focal onset seizures prevail among the aged. Generalized seizures are uncommon, starting usually earlier in life but exacerbating in later years. Motor phenomena are less frequently seen than among younger individuals. Seizures are mainly characterized by impairment of awareness, disturbed cognition and confusion, both ictally and postictally. Unresponsiveness may occur during non-epileptic events too, which further challenges seizure recognition. Epilepsy and dementia are bi-directionally related: dementia carries an increased risk of developing epilepsy and vice versa. Up to 45 % of the aged with new onset seizures present with status epilepticus (SE). SE among the elderly is more often focal motor; non-convulsive status epilepticus (NSCE) constitutes 10-25 %.

Illness representations of people with later-onset functional seizures

PURPOSE

Although functional seizures can start at any age, little is known about the individuals for whom onset occurs after the age of 40. It has been proposed that health-related traumatic events are more relevant causal factors for people with 'later-onset functional seizures' than for those whose functional seizures begin earlier in life, however, the illness representations of people with later-onset functional seizures have not yet been investigated. This study aimed to understand the experiences and illness representations of people with later-onset functional seizures.

METHODS

This was a mixed-methods study. People with later-onset functional seizures were recruited via a neurologist's caseload and online membership-led organisations. Semi-structured interview transcripts were analysed using Template Analysis according to the Common-Sense Model (CSM). Self-report measures of demographic and clinical details were collected to characterise the sample and verify themes.

RESULTS

Eight people with later-onset functional seizures participated in the study. Illness representations relating to all domains of the CSM as well as an additional theme of 'Triggers' were identified. Functional seizures were characterised as a mysterious brain disorder analogous to a computer malfunction and involving involuntary movements associated with alterations in consciousness. Perceptions of duration were indefinite, and triggers were unknown or at the extremes of autonomic arousal. Half of the sample identified health-related events/trauma as causal. Opinions were divided on 'cumulative life stress' as a causal factor. Most perceived themselves to have limited or no control but having 'control' over seizures was conceptualised as different to reducing their likelihood, frequency, or impact. Later-onset functional seizures were viewed as being more detrimental for caring and financial responsibilities but to have advantages for acceptance.

CONCLUSIONS

This is the first study to assess the illness representations of people with later-onset functional seizures. Many themes were similar to those identified in samples including people with earlier-onset functional seizures. Health-related trauma or events were the most strongly endorsed perceived causal factor, but with the exception of 'consequences', all representations were characterised by uncertainty. Clinicians should hold in mind the interaction between life stage and the consequences of later-onset functional seizures.

Title: Functional seizures across the adult lifespan: female sex, delay to diagnosis and disability

OBJECTIVE

The clinical characteristics of functional seizures may vary based on age-of-onset or age-of-presentation. Description of age-related differences has focused on three categories: pediatric, young-adult, and older-adult. We evaluated how factors continuously varied based on age-of-presentation across the adult lifespan.

METHODS

Based on cross-sectional data from 365 adult (18 to 88 years old) patients with documented diagnoses of functional seizures, we evaluated how the quantity and prevalence of specific ictal behaviors, historical factors, and comorbidities varied based on patient age-of-presentation using sequential weighted averages.

RESULTS

Four factors changed prominently with age-of-presentation: female predominance decreased at two inflection points - ages 35 and 62; the prevalence of work disability was higher until age-of-presentation 30 then plateaued at 80%; there was greater delay to diagnosis in older patients; and comorbidities was higher with age-of-presentation, starting from early adulthood. The proportion of patients who presented with functional seizures decreased after 50. Ictal behavior did not substantially vary with age-of-presentation.

CONCLUSION

The time from onset to diagnosis increased with age-of-presentation, which may be related to increased comorbidities and the misconception that FS do not start in older age. The female predominance decreased nonlinearly with age. By age 30, most patients' seizures already had substantial association with unemployment. These findings emphasize that patients can develop functional seizures at any age. The rapid development of disability relatively early in life, which then stays at a high prevalence rate, demonstrates the need for prompt referral for definitive diagnosis and treatment.

Psychiatric and cognitive characteristics of older adults admitted to a Video-EEG monitoring (VEM) unit

OBJECTIVE

To compare the clinical, psychiatric, and cognitive characteristics of older with younger patients presenting to a video-EEG monitoring (VEM) unit.

METHOD

This was a retrospective case-control study involving patients admitted for VEM over a two-year period (from April 2018 to April 2020) at two comprehensive epilepsy units. Patients were categorized into an older (≥60 years) and a younger (<60 years) group. Younger patients were individually matched to older adults to form a matched younger group. Diagnosis was determined by a consensus opinion of epileptologists, neurologists, and neuropsychiatrists. The main diagnostic categories were epilepsy, psychogenic nonepileptic seizures (PNES), and 'other' diagnosis (non-diagnostic and other nonepileptic diagnoses). Clinical psychiatric diagnoses were obtained from neuropsychiatric reports. Objective cognitive function was measured with the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG). Subjective cognitive function was assessed using the Quality of Life in Epilepsy Inventory-89 (QOLIE-89) cognitive subscales.

RESULTS

Five-hundred and thirty three patients (71 older, 462 younger) aged 16-91 years were admitted to the VEM unit during the study period. There was a diagnosis of focal epilepsy in 55% of the older group and 48% of the younger group, generalized epilepsy in 3% of the older group and 10% of the younger group, and 'other' in 32% of the older group and 19% of the younger group. Ten percent (2 males and 5 females) of the older group were diagnosed with PNES compared to 22% of the younger group (p = 0.016). A depressive disorder was diagnosed in 34% of the older group and 24% of the younger group (p = 0.20). An anxiety disorder was diagnosed in 15% of the older group and 25% of the younger group (p = 0.15). Mild neurocognitive disorder was more common in the older group (34%) compared to the matched younger group (34% vs 3%, p < 0.001). The older group had lower mean NUCOG scores compared to the matched younger group (79.49 vs 87.73, p = <0.001). There was no evidence for a relationship between mean NUCOG score and overall subjective cognitive difficulties for the older group (r = 0.03, p = 0.83). Among older adults, those diagnosed with PNES had more experiences of childhood trauma. Measures of dissociation, depression, or general anxiety did not differ between PNES and non-PNES diagnoses in the older group.

CONCLUSION

Psychiatric comorbidities are common among older adults admitted for VEM. The psychological impact of epilepsy and risk factors for PNES seen in younger patients are also applicable in the older group. The older group demonstrated more cognitive impairments than the younger group, although these were usually unrecognized by individuals. Older adults admitted to VEM will benefit from psychiatric and neuropsychological input to ensure a comprehensive care approach to evaluation and management.

Psychogenic Non-epileptic Seizures and Pseudo-Refractory Epilepsy, a Management Challenge

Psychogenic nonepileptic seizures (PNES) are neurobehavioral conditions positioned in a gray zone, not infrequently a no-man land, that lies in the intersection between Neurology and Psychiatry. According to the DSM 5, PNES are a subgroup of conversion disorders (CD), while the ICD 10 classifies PNES as dissociative disorders. The incidence of PNES is estimated to be in the range of 1.4-4.9/100,000/year, and the prevalence range is between 2 and 33 per 100,000. The International League Against Epilepsy (ILAE) has identified PNES as one of the 10 most critical neuropsychiatric conditions associated with epilepsy. Comorbidity between epilepsy and PNES, a condition leading to "dual diagnosis," is a serious diagnostic and therapeutic challenge for clinicians. The lack of prompt identification of PNES in epileptic patients can lead to potentially harmful increases in the dosage of anti-seizure drugs (ASD) as well as erroneous diagnoses of refractory epilepsy. Hence, pseudo-refractory epilepsy is the other critical side of the PNES coin as one out of four to five patients admitted to video-EEG monitoring units with a diagnosis of pharmaco-resistant epilepsy is later found to suffer from non-epileptic events. The majority of these events are of psychogenic origin. Thus, the diagnostic differentiation between pseudo and true refractory epilepsy is essential to prevent actions that lead to unnecessary treatments and ASD-related side effects as well as produce a negative impact on the patient's quality of life. In this article, we review and discuss recent evidence related to the neurobiology of PNES. We also provide an overview of the classifications and diagnostic steps that are employed in PNES management and dwell on the concept of pseudo-resistant epilepsy.

Epilepsy in the Elderly: Treatment and Consideration of Comorbid Diseases

Epilepsy is the third most common neurological disorder affecting older adults after stroke and dementia, and the incidence of epilepsy is increasing rapidly in this population. A further increase in the incidence and prevalence of epilepsy is expected in aging societies. The establishment of a correct differential diagnosis between epilepsy and other seizure disorders that are common in the elderly is crucial. The symptoms of seizures in the elderly may be different from those in younger populations. The diagnosis is difficult, probably because of nonspecific characteristics, short-term symptoms, and absence of witnesses. There are three important issues in the treatment of epilepsy in the elderly: changes in pharmacokinetic parameters, polytherapy (including non-antiepileptic and antiepileptic drugs), and susceptibility to adverse drug effects. Antiepileptic drugs (AEDs) with fewer adverse effects, including cognitive effects, and AEDs without significant pharmacokinetic drug interactions are needed. Several studies found that stroke was strongly associated with a high incidence of early seizures and epilepsy. Stroke is also one of the major causes of status epilepticus. Cortical involvement and large lesions are strongly associated with the development of seizures and epilepsy. The severity of the initial neurological deficit is a strong clinical predictor of seizures after ischemic stroke. The optimal quality of life of dementia patients cannot be achieved without a proper diagnosis of coexisting epilepsy.

Psychogenic nonepileptic seizures: a concise review

Psychogenic nonepileptic seizures (PNES) are commonly diagnosed and treated at epilepsy centers; however, their neurobiology is still poorly understood. Diagnosis relies on a multidisciplinary evaluation and is usually based on different combinations of data. They are diagnosed most reliably by recording a seizure while under video-EEG monitoring. Treatment includes multiple phases. Fewer than 40% of adults with PNES are expected to become seizure-free within 5 years after diagnosis. This article presents a concise review of the current literature about the definition, diagnosis, epidemiology, clinical characteristics, treatment, and prognosis of PNES.

Epidemiology of psychogenic nonepileptic seizures

We critically review the existing literature about the epidemiology (i.e., diagnosis, occurrence, age, gender, comorbidity with epilepsy, associated factors, prognosis, mortality, and cost) of psychogenic nonepileptic seizures (PNES) and provide suggestions for future research. Psychogenic nonepileptic seizures are commonly diagnosed at epilepsy centers. The diagnosis of PNES relies on a multidisciplinary evaluation and is usually based on different combinations of data. Recording a seizure, while under video-EEG monitoring, is the most reliable diagnostic test. However, not all patients present with seizures while under video-EEG monitoring. Furthermore, not all epileptic seizures produce visible changes in the scalp EEG. The incidence of PNES was estimated to be 1.4-4.9/100,000/year in three previous studies, and the prevalence was calculated to be between 2 to 33 per 100,000 in one study, making it a significant neuropsychiatric condition. However, there remains a scarcity of data about the epidemiology of PNES, and extant studies that assessed the epidemiological characteristics of PNES have significant limitations. For example, inconsistencies with regard to the age of patients studied and lack of standardization of the diagnostic criteria are some of the significant limitations among studies. In conclusion, PNES merit further epidemiological and pathophysiological investigation. A more precise definition and clear guidance on standards for the diagnosis might influence the direction of future research. Well-designed prospective population-based studies to clarify the epidemiology of PNES in various parts of the world, including an evaluation of the predisposing, precipitating, and perpetuating factors in cross-cultural comparisons is required.

[French guidelines on electroencephalogram]

Electroencephalography allows the functional analysis of electrical brain cortical activity and is the gold standard for analyzing electrophysiological processes involved in epilepsy but also in several other dysfunctions of the central nervous system. Morphological imaging yields complementary data, yet it cannot replace the essential functional analysis tool that is EEG. Furthermore, EEG has the great advantage of being non-invasive, easy to perform and allows control tests when follow-up is necessary, even at the patient's bedside. Faced with the advances in knowledge, techniques and indications, the Société de Neurophysiologie Clinique de Langue Française (SNCLF) and the Ligue Française Contre l'Épilepsie (LFCE) found it necessary to provide an update on EEG recommendations. This article will review the methodology applied to this work, refine the various topics detailed in the following chapters. It will go over the summary of recommendations for each of these chapters and underline proposals for writing an EEG report. Some questions could not be answered by the review of the literature; in those cases, an expert advice was given by the working and reading groups in addition to the guidelines.

Conversion disorder as psychogenic nonepileptic seizures in suspected cancer: a case report

Psychogenic nonepileptic seizures (PNES), a form of conversion disorder, are paroxysmal episodes resembling epilepsy while lacking electrographic correlation. The phenomenon has rarely been reported in elderly patients and has not been associated with a new-onset medical diagnosis. We present the case of an 81-year-old female with no past psychiatric or traumatic history who developed PNES within the context of a new, suspected cancer. To our knowledge, this is the first such reported case of a suspected cancer (or otherwise medical) diagnosis contributing directly and temporally to the development of PNES. Discussion of involved psychosocial variables follows the vignette, and a brief review of relevant literature is offered.

Outcome of newly-diagnosed epilepsy in older patients

INTRODUCTION

The annual incidence of seizure disorders rises sharply after the age of 60. Treatment is complicated by the normal physiological changes of aging, comorbid diseases, and polypharmacy. Despite this, approximately 80% of the patients become seizure-free.

OBJECTIVES

The objectives of this study were to (1) analyze the outcome of a cohort of patients with newly-diagnosed epilepsy over the age of 65, (2) describe epilepsy etiology and seizure type, and (3) classify the outcome according to the latest ILAE classification proposal for drug-resistant epilepsy (2010).

METHODS

All patients with newly-diagnosed epilepsy over the age of 65 who were evaluated in two different institutions were included. Seizures and epilepsy syndromes were classified according to the International League Against Epilepsy proposal (2010). Epilepsy outcomes were also analyzed according to the proposal of the ILAE Commission on Therapeutic Strategies (2010).

RESULTS

One hundred and twenty-two patients were included with a median follow-up time of 15 months. Median age of diagnosis was 78 years. Seventy-seven patients (55%) had epilepsy of unknown cause, and 55 (45%) had structural-metabolic epilepsy. The proportions of seizure-free patients at 6, 12, 18, and 24 months were 90%, 77%, 74%, and 67%, respectively. Thirty percent of patients experienced adverse effects (AEs). We found a statistically significant trend toward a higher frequency of AEs as the number of concomitant medications rose and in younger patients. According to the 2010 ILAE classification proposal for drug-resistant epilepsy criteria, 55.8% of the patients were seizure-free, 12.3% had treatment failure, and 32% had undetermined seizure outcome.

CONCLUSION

Patients with newly-diagnosed epilepsy after the age of 65 have very good chances of achieving seizure control with AED treatment. It seems that fulfilling the ILAE classification proposal for drug-resistant epilepsy (2010) criteria for seizure freedom was more difficult in our cohort. Older patients also seem to be more prone to suffering from AEs.

Temporal lobe epilepsy in the elderly

The incidence of epilepsy has bimodal distribution peaking at the extremes of life. Incidence is greater in younger and older age groups (Hauser et al., 1993, Sidenvall et al., 1993, Forsgren et al., 1996, and Olafsson et al., 2005). As the world population ages more elders with epilepsy will be identified. In the high-income countries with longer life expectancy, the number of elders with epilepsy will be even higher. CPSs account for 40% of all seizure types in the elderly (Hauser et al., 1992); however, the proportion with temporal lobe epilepsy (TLE) is uncertain.

A critical appraisal on the utility of long-term video-EEG monitoring in older adults

BACKGROUND

World-over, the majority of patients undergoing video-EEG monitoring (VEM) are in their second or third decades. Although elderly represent the fastest growing segment of population with epilepsy, only few of them undergo VEM. We critically evaluated the utility of VEM in the diagnosis and long-term management of older adults with paroxysmal behavioral events.

METHODS

148 consecutive patients aged 45 and above, who underwent long-term (≥8 h) inpatient VEM from 1996 to 2009 formed the study cohort. Utilizing a structured proforma, we gathered their demographic, clinical, electrophysiological and long-term outcome data. VEM was considered as "useful" when it changed the diagnosis and/or management; it was "corroborative" when it helped the treating physician to confirm the diagnosis and "not useful" when it neither helped to improve the diagnosis nor the management.

RESULTS

The mean age was 51.3 (SD 6.4) years; mean duration of VEM was 69.3 h. Out of 117 patients with a diagnosis of epileptic seizures referred for presurgical evaluation or classification, VEM was "useful" or "corroborative" in 111 patients (94.8%; p=0.0001). It was also "useful" or "corroborative" in 29 out of 31 patients (93.5%) referred with a suspicion of associated or pure psychogenic non-epileptic seizures (p=0.0001). None developed any complications during monitoring. At a mean follow-up of 37.7 months there was significant reduction in AED usage in patients with epilepsy (p=0.0001) and epilepsy with associated PNES (p=0.001). At a mean follow-up of 34.2 months, all patients with pure PNES were event-free and medication-free at last follow-up (p=0.002). Twenty-three patients (19.6%) underwent surgery, all except one remaining seizure-free at a mean follow-up of 39.2 months.

CONCLUSIONS

VEM is a safe and cost-effective investigation strategy in older-adults. It aided in improving the diagnosis, offered better treatment including surgery and helped in excluding non-epileptic paroxysmal events in majority.

The yield of routine EEG in geriatric patients: A prospective hospital-based study

STUDY AIM

To study the yield of routine EEG in geriatric patients.

PATIENTS AND METHODS

We examined standard EEG recordings of 701 patients aged 84.6±6.4 years. These were performed over a 15 month-period in a geriatric hospital. The majority of patients were hospitalized and 46.5% suffered from multiple medical problems.

RESULTS

We found EEG abnormalities in 392/701 (56%) patients. These consisted of permanent diffuse slowing, either isolated (17.1%) or with intermixed epileptiform abnormalities (2.4%), focal slowing (15.4%), intermittent diffuse slowing (8.9%), triphasic waves (1.14%), periodic epileptiform discharges (0.57%), flat and inactive tracing (0.14%), status epilepticus (0.99%), seizures (0.42%), interictal epileptiform abnormalities (8.7%). Epileptiform abnormalities (both ictal and interictal) were observed in 92/701 (13.1%) patients. These were focal in the majority of cases (85.9%), most frequent in temporal regions (42%), followed by centroparietal (20.2%) and temporo-parieto-occipital carrefour regions (17.2%), but less frequent in frontal (6.3%) and occipital regions (3.8%). We found sleep activity without other EEG abnormalities in 13.7% of patients and subclinical rhythmic electrographic discharge in adult (SREDA) in 1% of cases.

CONCLUSIONS

In this study, EEG abnormalities were very common, which reflects the high frequency of cerebral dysfunction in geriatric patients. These abnormalities are of various types, often suggestive of different aetiologies, and may be helpful in clinical management.

Video-EEG monitoring of paroxysmal events in the elderly

OBJECTIVES

To determine the importance of video-EEG monitoring (VEM) in elderly patients with various paroxysmal events.

MATERIAL AND METHODS

We retrospectively identified 16 subjects > or = 60 years old out of 834 (1.9%; 7 females, mean age 67.8 +/- 7.7 years), who were admitted to the Video-EEG Unit between 1997 and 2005 and compared data between those with and without epileptic events.

RESULTS

Epilepsy was confirmed in six patients, psychogenic non-epileptic seizures (NES) were diagnosed in seven, one patient had NES and epilepsy whereas the recorded events were non-conclusive in two. NES patients had a higher predisposition to psychiatric disturbances (P<0.02). Following VEM and management alteration, the frequency of monthly events decreased significantly for the cohort as a whole (P<0.001). VEM directly influenced the diagnosis, treatment and outcome of 14 of 16 (88%) patients.

CONCLUSION

Video-EEM plays a vital role in the evaluation of paroxysmal events in the elderly, but is vastly underutilized in this population group.

Epileptic fits and epilepsy in the elderly: general reflections, specific issues and therapeutic implications

Seizures and epilepsy are commonly encountered in the elderly. Diagnosis is not always straightforward as reliable history is often difficult to obtain and EEG findings can be non-specific. When to treat and how may be difficult choices as adequate studies in elderly are rather scarce. Treatment should be based on careful assessment and comparison of risk/benefit profiles of various anti-epileptic drugs (AEDs) in this specific elderly population. Since most AEDs are effective in terms of seizure control in the elderly, the choice of treatment is often determined by tolerability, pharmacokinetic profile and drug interactions of AEDs. As recently introduced AEDs have a better safety profile compared to older agents it seems logical to initiate treatment in the frail elderly patient with those more modern AEDs. In this review some distinctive clinical features of epilepsy in the elderly are discussed in three sections (general issues, special issues and selected treatment options with special reference to medicinal treatment).