Debate: When does a seizure imply epilepsy?

New Onset (Incidence) of Epilepsy and Seizures in Nursing Home Residents

OBJECTIVE

The point prevalence of epilepsy is high in nursing homes (NH), but the incidence of epilepsy after admission is unknown. This study was done to determine the incidence of epilepsy/seizure (epi/sz) comorbid with other conditions in older adult NH residents.

DESIGN

Retrospective evaluation of Minimum Data Set records to identify new onset epi/sz in NH residents.

SETTING AND PARTICIPANTS

Five cross-sectional cohorts of all residents in any Medicare/Medicaid certified NH in the United States on July 15 of each year 2003-2007.

MEASURES

Epi/sz was identified by International Classification of Diseases, Ninth Revision codes (345.xx or 780.39) or check box on the Minimum Data Set. Those with no such code on admission and with 1 to 3 plus years of follow-up (n = 3,609,422) were followed through 2007 or end of stay.

RESULTS

Overall incidence of epi/sz was 16.42/1000 patient years (PY). Incidence was highest in the first year after admission and declined thereafter. There were more women (n = 2,523,951) than men (n = 1,089,631), but men had a higher incidence (21.17/1000PY) compared with women (14.81/1000PY). Although the 65‒74 years of age cohort included fewer residents (n = 594,722) compared with the age 85 years + cohort (n = 1,520,167), the younger residents had the highest incidence (28.53/1000 PY) compared with the oldest, 10.22/1000 PY for the age 85+ years cohort. The highest incidences were among those with brain tumor (122.55/1000PY), followed by head injury (45.66/1000PY). Overall, 714,340 had a diagnosis of stroke, and incidence was 27.52/1000PY. Those with none of selected risk factors had an overall incidence of 12.45/1000PY.

CONCLUSIONS AND IMPLICATIONS

The incidence of epi/sz in older individuals after admission to a NH is high. There is a need to develop practice approaches to best manage this large cohort. There does not appear to be a uniform approach to managing new onset epilepsy in NHs at this time. Studies to develop evidence for practice guidelines are needed.

Clinical outcome of recurrent afebrile seizures in children with benign convulsions associated with mild gastroenteritis

PURPOSE

To assess the clinical outcome and evolution of recurrent afebrile seizures in children initially diagnosed with benign convulsions associated with mild gastroenteritis (CwG).

METHODS

We reviewed and analyzed the medical records of 37 patients who were diagnosed as CwG at onset, followed by recurrent afebrile seizures and followed up for at least 24 months.

RESULTS

The follow-up period ranged from 2 to 7 years (median, 40.1 months).Three patterns of recurrent afebrile seizures were recorded: afebrile seizures associated with gastrointestinal infection (AS-GI, n = 25), afebrile seizures associated with non-gastrointestinal infection (AS-nGI, n = 9), and unprovoked seizures (US, n = 3). Twenty eight patients (75.7%) had a second episode within 6 months after the first seizures. Five cases (13.5%) suffered three episodes of afebrile seizures. Seizure characteristics of the three patterns were similar, manifesting as clustered seizures in the majority. Focal epileptic activities in interictal EEG were found in 3 cases (9.4%) at onset, 10 cases (28.6%) at the second episode, respectively. Six patients were prescribed anti-epileptic drugs with apparently good responses. During at least 2 years' follow-up, all the cases showed normal psychomotor development. Only one patient was diagnosed with epilepsy.

CONCLUSIONS

All the recurrent afebrile seizures initially diagnosed as CwG, irrespective of the kinds and frequency of relapses, showed favorable prognoses. CwG maybe falls within the category of situation-related seizures, rather than epilepsy.

Antiseizure, antidepressant, and antipsychotic medication prescribing in elderly nursing home residents

OBJECTIVE

The incidence of epilepsy is highest in the elderly and the prevalence of epilepsy is higher in nursing home residents than in other cohorts. Co-medications that act in the central nervous system (CNS) are frequently prescribed in this population. The objective was to identify the most commonly prescribed antiseizure drugs (ASDs) and determine the frequency of use of antipsychotic and antidepressant medications in elderly nursing home residents receiving ASDs.

METHODS

Data were obtained from a pharmacy database serving 18,752 patients in Minnesota and Wisconsin nursing homes. Prescribing information was available on ASD, antidepressant, and antipsychotic drugs on one day in October 2013. The frequency distribution by age, formulation, trademarked/generic drugs, route of administration, and multiple drug combinations were determined.

RESULTS

Overall, 66.8% of 18,752 residents received at least one CNS-active drug as classified by the Generic Product Identifier classification system. For those 65years and older, ASDs were prescribed for 14.3% residents. Gabapentin comprised 7.3%; valproate 3.0%; levetiracetam 1.8%; and phenytoin 0.9%. An antidepressant was used in 64.2% of persons prescribed an ASD. Antidepressant use varied for specific ASDs and ranged from 50 to 75%. An antipsychotic medication was used in 30% of persons prescribed an ASD and ranged from 16.8 to 54.2% for specific ASDs. Both antidepressant and antipsychotic use occurred in 22.2% of persons prescribed an ASD, respectively.

SIGNIFICANCE

The pattern of CNS-active drug use has changed from previous years in this geographic region. Use of phenytoin has declined markedly, but antidepressant use has increased substantially. The CNS side effect profile of these medications and the possible long-term consequences in this population can greatly complicate their therapy.

Prevalence of epilepsy/seizures as a comorbidity of neurologic disorders in nursing homes

OBJECTIVE

To determine the prevalence of epilepsy/seizure (epi/sz) comorbid with other neurologic disorders in elderly nursing home residents and to examine demographic and regional variability and associations with clinical characteristics.

METHODS

We studied 5 cross-sectional cohorts of all residents in any Medicare/Medicaid-certified nursing home in the United States on July 15 of each year from 2003 to 2007. Epi/sz was identified by ICD-9 codes (345.xx or 780.39) or check box (Minimum Data Set). Epi/sz prevalence was stable across all years, so only 2007 data were examined further. Logistic regression with generalized estimating equations was used to model cross-sectional prevalence of epi/sz as a function of demographics and neurologic comorbidities of interest, with adjustment for clinical characteristics, including cognitive status, comorbidity burden, medication burden, and activities of daily living.

RESULTS

Point prevalence of epi/sz in 2007 was 7.7% (n = 91,372 of N = 1,186,579) differing by geographical region, race/ethnicity, age group, and sex. Neurologic conditions having the highest association with epi/sz were brain tumor (epi/sz prevalence 23.4%-35.2%), head injury (17.9%), hemiplegia (17.7%), and stroke (13.7%). Epi/sz comorbid with stroke or dementia had a strong decreasing association with age (65-74 years had ≈3.8-times higher odds of epi/sz than 85+ years). Activities of daily living, comorbidity burden, and cognition scores were worse in persons with than without epi/sz.

CONCLUSIONS

The prevalence of epi/sz in the elderly nursing home population is >7-fold higher compared to community-dwelling elderly and is 7 to 30 times higher among those with certain comorbid neurologic conditions. Demographics and clinical characteristics had weaker associations with epi/sz prevalence.

Neuroactive compounds obtained from arthropod venoms as new therapeutic platforms for the treatment of neurological disorders

The impact of neurological disorders in society is growing with alarming estimations for an incidence increase in the next decades. These disorders are generally chronic and can affect individuals early during productive life, imposing real limitations on the performance of their social roles. Patients can have their independence, autonomy, freedom, self-image, and self-confidence affected. In spite of their availability, drugs for the treatment of these disorders are commonly associated with side effects, which can vary in frequency and severity. Currently, no effective cure is known. Nowadays, the biopharmaceutical research community widely recognizes arthropod venoms as a rich source of bioactive compounds, providing a plethora of possibilities for the discovery of new neuroactive compounds, opening up novel and attractive opportunities in this field. Several identified molecules with a neuropharmacological profile can act in the central nervous system on different neuronal targets, rendering them useful tools for the study of neurological disorders. In this context, this review aims to describe the current main compounds extracted from arthropod venoms for the treatment of five major existing neurological disorders: stroke, Alzheimer’s disease, epilepsy, Parkinson’s disease, and pathological anxiety.

Long-term follow-up in children with benign convulsions associated with gastroenteritis

BACKGROUND

The outcome of benign convulsions associated with gastroenteritis (CwG) has generally been reported as being excellent. However, these data need to be confirmed in studies with longer follow-up evaluations.

AIM

To assess the long-term neurological outcome of a large sample of children presenting with CwG.

METHODS

We reviewed clinical features of 81 subjects presenting with CwG (1994-2010) from three different Italian centers with a follow-up period of at least 3 years.

RESULTS

Follow-up period ranged from 39 months to 15 years (mean 9.8 years). Neurological examination and cognitive level at the last evaluation were normal in all the patients. A mild attention deficit was detected in three cases (3.7%). Fourteen children (17.3%) received chronic anti-epileptic therapy. Interictal EEG abnormalities detected at onset in 20 patients (24.7%) reverted to normal. Transient EEG epileptiform abnormalities were detected in other three cases (3.7%), and a transient photosensitivity in one (1.2%). No recurrence of CwG was observed. Three patients (3.7%) presented with a febrile seizure and two (2.5%) with an unprovoked seizure, but none developed epilepsy.

CONCLUSIONS

The long-term evaluation of children with CwG confirms the excellent prognosis of this condition, with normal psychomotor development and low risk of relapse and of subsequent epilepsy.

Are afebrile seizures associated with minor infections a single seizure category? A hospital-based prospective cohort study on outcomes of first afebrile seizure in early childhood

OBJECTIVE

To explore if afebrile seizures associated with minor infections are a single category of seizure, or a set of different kinds of seizures.

METHODS

We conducted this prospective cohort study on three kinds of first afebrile seizure: first afebrile seizure associated with gastrointestinal infection (AS-GI), first afebrile seizure associated with nongastrointestinal infection (AS-nGI), and first unprovoked seizure (US). The Kaplan-Meier estimate risks of recurrent seizures were analyzed and compared pairwise. The characteristics of recurrent seizures were also compared pairwise.

RESULTS

The Kaplan-Meier estimate risks of recurrent seizure at 2 years of the AS-GI, AS-nGI, and US groups were 6.9%, 23.7%, and 37.8%, respectively. The pairwise differences were significant between the AS-GI and US groups (p < 0.001) and between the AS-GI and AS-nGI groups (p = 0.001), but not significant between the US and AS-nGI groups (p = 0.066). Among unprovoked subsequent seizures in patients with recurrence, the pairwise differences were significant between the AS-GI and US groups (p < 0.001) and between the AS-GI and AS-nGI groups (p = 0.005), but not significant between the US and AS-nGI groups (p = 0.417).

SIGNIFICANCE

Afebrile seizures associated with minor infections are indeed of two distinguishable kinds: AS-GI, if free of risk factors such as a family history of epilepsy, had a better prognosis and should be categorized as an acute symptomatic seizure, whereas patients with first AS-nGI, like patients with first US, may have recurrent unprovoked seizures, which suggests this category's essential difference from AS-GI.

Epilepsy in cats: theory and practice

The veterinary literature on epilepsy in cats is less extensive than that for dogs. The present review summarizes the most important human definitions related to epilepsy and discusses the difficulties in applying them in daily veterinary practice. Epileptic seizures can have a wide range of clinical signs and are not necessarily typical in all cases. Whether a seizure event is epileptic can only be suspected based on clinical, laboratory, and neuroimaging findings as electroencephalography diagnostic techniques have not yet been developed to a sufficiently accurate level in veterinary medicine. In addition, the present review aims to describe other diagnoses and nonepileptic conditions that might be mistaken for epileptic seizures. Seizures associated with hippocampal lesions are described and discussed extensively, as they seem to be a special entity only recognized in the past few years. Furthermore, we focus on clinical work‐up and on treatment that can be recommended based on the literature and summarize the limited data available relating to the outcome. Critical commentary is provided as most studies are based on very weak evidence.

On the midway to epilepsy: is cortical excitability normal in patients with isolated seizures?

Paired pulse transcranial magnetic stimulation was used to investigate differences in cortical excitability between patients with isolated (unrecurrent, unprovoked) seizures and those with epilepsy. Compared to controls, cortical excitability was higher in the isolated seizure group at 250-300 ms. Compared to epilepsy, cortical excitability was lower in patients with isolated seizures also at 250 and 300 ms. Lowered seizure threshold caused by disturbances within inhibitory circuits is present in patients who experience a seizure even if no further seizures occur.

Changes on D2-like receptor induced Gi protein activation and hippocampal dopamine release in kindled rats

The present study aimed to characterize dopamine release in the hippocampus and D2-like receptor-induced Gi protein activation in several brain areas of fully kindled rats. During the interictal period, kindled rats showed lower extracellular levels of dopamine when compared with those obtained in the control group under basal conditions, a situation that was not modified when an afterdischarge was evoked. Hippocampal perfusion of sulpiride, a D2 receptor antagonist, enhanced dopamine release, which was more evident when an afterdischarge was induced in kindled rats. In addition, sulpiride perfusion was associated with longer seizure duration. Functional autoradiography experiments revealed increased [(35)S]GTPγS incorporation as a consequence of D2-like receptor activation in different brain areas of fully kindled animals, including the ventral hippocampus. The present study reveals that hippocampal kindling is associated with alterations in dopamine release and D2-like receptor-induced neurotransmission.

Antiepileptic and antiepileptogenic performance of carisbamate after head injury in the rat: blind and randomized studies

Carisbamate (CRS) exhibits broad acute anticonvulsant activity in conventional anticonvulsant screens, genetic models of absence epilepsy and audiogenic seizures, and chronic spontaneous motor seizures arising after chemoconvulsant-induced status epilepticus. In add-on phase III trials with pharmacoresistant patients CRS induced < 30% average decreases in partial-onset seizure frequency. We assessed the antiepileptogenic and antiepileptic performance of subchronic CRS administration on posttraumatic epilepsy (PTE) induced by rostral parasaggital fluid percussion injury (rpFPI), which closely replicates human contusive closed head injury. Studies were blind and randomized, and treatment effects were assessed on the basis of sensitive electrocorticography (ECoG) recordings. Antiepileptogenic effects were assessed in independent groups of control and CRS-treated rats, at 1 and 3 months postinjury, after completion of a 2-week prophylactic treatment initiated 15 min after injury. The antiepileptic effects of 1-week CRS treatments were assessed in repeated measures experiments at 1 and 4 months postinjury. The studies were powered to detect ~50 and ~40% decreases in epilepsy incidence and frequency of seizures, respectively. Drug/vehicle treatment, ECoG analysis, and [CRS](plasma) determination all were performed blind. We detected no antiepileptogenic and an equivocal transient antiepileptic effects of CRS despite [CRS](plasma) comparable with or higher than levels attained in previous preclinical and clinical studies. These findings contrast with previous preclinical data demonstrating large efficacy of CRS, but agree with the average effect of CRS seen in clinical trials. The data support the use of rpFPI-induced PTE in the adolescent rat as a model of pharmacoresistant epilepsy for preclinical development.

Impact of injury location and severity on posttraumatic epilepsy in the rat: role of frontal neocortex

Human posttraumatic epilepsy (PTE) is highly heterogeneous, ranging from mild remitting to progressive disabling forms. PTE results in simple partial, complex partial, and secondarily generalized seizures with a wide spectrum of durations and semiologies. PTE variability is thought to depend on the heterogeneity of head injury and patient's age, gender, and genetic background. To better understand the role of these factors, we investigated the seizures resulting from calibrated fluid percussion injury (FPI) to adolescent male Sprague-Dawley rats with video electrocorticography. We show that PTE incidence and the frequency and severity of chronic seizures depend on the location and severity of FPI. The frontal neocortex was more prone to epileptogenesis than the parietal and occipital, generating earlier, longer, and more frequent partial seizures. A prominent limbic focus developed in most animals, regardless of parameters of injury. Remarkably, even with carefully controlled injury parameters, including type, severity, and location, the duration of posttraumatic apnea and the age and gender of outbred rats, there was great subject-to-subject variability in frequency, duration, and rate of progression of seizures, indicating that other factors, likely the subjects' genetic background and physiological states, have critical roles in determining the characteristics of PTE.

Alcohol consumption, unprovoked seizures, and epilepsy: a systematic review and meta-analysis

PURPOSE

The purpose of this research was to analyze and quantify the association between alcohol consumption and epilepsy as an independent disease, in part operationalized by the occurrence of unprovoked seizures, as well as to examine causality.

METHODS

Systematic review, meta-analysis.

RESULTS

A strong and consistent association between alcohol consumption and epilepsy/unprovoked seizures was found with an overall relative risk (RR) of 2.19 [95% confidence interval (CI) 1.83-2.63]. There was a dose-response relationship between the amount of alcohol consumed daily and the probability of the onset of epilepsy. Individuals consuming an average of four, six, and eight drinks daily had RRs of 1.81 (95% CI 1.59-2.07), 2.44 (95% CI 2.00-2.97), and 3.27 (95% CI 2.52-4.26), respectively, compared to nondrinkers. Several pathogenic mechanisms for the development of epilepsy in alcohol users were identified. Most of the relevant studies found that a high percentage of alcohol users with epilepsy would qualify for the criteria of alcohol dependence. Data were inconclusive regarding a threshold for the effect of alcohol, but most studies suggest that the effect may only hold for heavy drinking (four and more drinks daily).

DISCUSSION

The relationship between alcohol consumption and epilepsy and unprovoked seizures was quantified and several pathogenic mechanisms were suggested, although none of them has been proven to be the unique causative pathway for epilepsy. Certain limitations underlying this study require further research to clarify the outstanding statistical issues and pathogenesis of epilepsy in heavy drinkers.

Epilepsy in the elderly

The elderly, often defined as those 65 years or older, are the most rapidly growing segment of the population, and onset of epilepsy is higher in this age group than in any other. This paper reviews recent developments, including a new proposed definition of epilepsy, a transgenic mouse model of Alzheimer's disease that exhibits complex partial seizures, evidence that the highest incidence of epilepsy may occur after admission to a nursing home, a challenge to the vitamin D hypothesis of osteoporosis associated with antiepileptic drugs (AEDs), evidence that the genetic complement of hepatic isoenzymes is more predictive of metabolic rate than age, and data showing that there is considerable variability in serum levels of AEDs in many nursing home residents during constant dosing conditions.

Significance of the EEG in the decision to initiate antiepileptic treatment in patients with epilepsy: a perspective on recent evidence

The significance of electroencephalography in the prediction of seizure recurrence after a first unprovoked seizure remains a topic of debate. Opinion on the initiation of antiepileptic treatment after a first seizure also remains divided. However, in view of recent evidence, this article is intended to highlight the significance of a properly performed EEG in the decision to initiate antiepileptic drug treatment as early as possible to prevent further morbidity and other consequences.