Reliability of the early syndromic diagnosis in adults with new-onset epileptic seizures: A retrospective study of 116 patients attended in the emergency room

Prognosis of adults and children following a first unprovoked seizure

BACKGROUND

Epilepsy is clinically defined as two or more unprovoked epileptic seizures more than 24 hours apart. Given that, a diagnosis of epilepsy can be associated with significant morbidity and mortality, it is imperative that clinicians (and people with seizures and their relatives) have access to accurate and reliable prognostic estimates, to guide clinical practice on the risks of developing further unprovoked seizures (and by definition, a diagnosis of epilepsy) following single unprovoked epileptic seizure.

OBJECTIVES

1. To provide an accurate estimate of the proportion of individuals going on to have further unprovoked seizures at subsequent time points following a single unprovoked epileptic seizure (or cluster of epileptic seizures within a 24-hour period, or a first episode of status epilepticus), of any seizure type (overall prognosis). 2. To evaluate the mortality rate following a first unprovoked epileptic seizure.

SEARCH METHODS

We searched the following databases on 19 September 2019 and again on 30 March 2021, with no language restrictions. The Cochrane Register of Studies (CRS Web), MEDLINE Ovid (1946 to March 29, 2021), SCOPUS (1823 onwards), ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). CRS Web includes randomized or quasi-randomized, controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups including Epilepsy. In MEDLINE (Ovid) the coverage end date always lags a few days behind the search date.

SELECTION CRITERIA

We included studies, both retrospective and prospective, of all age groups (except those in the neonatal period (< 1 month of age)), of people with a single unprovoked seizure, followed up for a minimum of six months, with no upper limit of follow-up, with the study end point being seizure recurrence, death, or loss to follow-up. To be included, studies must have included at least 30 participants. We excluded studies that involved people with seizures that occur as a result of an acute precipitant or provoking factor, or in close temporal proximity to an acute neurological insult, since these are not considered epileptic in aetiology (acute symptomatic seizures). We also excluded people with situational seizures, such as febrile convulsions.

DATA COLLECTION AND ANALYSIS

Two review authors conducted the initial screening of titles and abstracts identified through the electronic searches, and removed non-relevant articles. We obtained the full-text articles of all remaining potentially relevant studies, or those whose relevance could not be determined from the abstract alone and two authors independently assessed for eligibility. All disagreements were resolved through discussion with no need to defer to a third review author. We extracted data from included studies using a data extraction form based on the checklist for critical appraisal and data extraction for systematicreviews of prediction modelling studies (CHARMS). Two review authors then appraised the included studies, using a standardised approach based on the quality in prognostic studies (QUIPS) tool, which was adapted for overall prognosis (seizure recurrence). We conducted a meta-analysis using Review Manager 2014, with a random-effects generic inverse variance meta-analysis model, which accounted for any between-study heterogeneity in the prognostic effect. We then summarised the meta-analysis by the pooled estimate (the average prognostic factor effect), its 95% confidence interval (CI), the estimates of I² and Tau² (heterogeneity), and a 95% prediction interval for the prognostic effect in a single population at three various time points, 6 months, 12 months and 24 months. Subgroup analysis was performed according to the ages of the cohorts included; studies involving all ages, studies that recruited adult only and those that were purely paediatric.

MAIN RESULTS

Fifty-eight studies (involving 54 cohorts), with a total of 12,160 participants (median 147, range 31 to 1443), met the inclusion criteria for the review. Of the 58 studies, 26 studies were paediatric studies, 16 were adult and the remaining 16 studies were a combination of paediatric and adult populations. Most included studies had a cohort study design with two case-control studies and one nested case-control study. Thirty-two studies (29 cohorts) reported a prospective longitudinal design whilst 15 studies had a retrospective design whilst the remaining studies were randomised controlled trials. Nine of the studies included presented mortality data following a first unprovoked seizure. For a mortality study to be included, a proportional mortality ratio (PMR) or a standardised mortality ratio (SMR) had to be given at a specific time point following a first unprovoked seizure. To be included in the meta-analysis a study had to present clear seizure recurrence data at 6 months, 12 months or 24 months. Forty-six studies were included in the meta-analysis, of which 23 were paediatric, 13 were adult, and 10 were a combination of paediatric and adult populations. A meta-analysis was performed at three time points; six months, one year and two years for all ages combined, paediatric and adult studies, respectively. We found an estimated overall seizure recurrence of all included studies at six months of 27% (95% CI 24% to 31%), 36% (95% CI 33% to 40%) at one year and 43% (95% CI 37% to 44%) at two years, with slightly lower estimates for adult subgroup analysis and slightly higher estimates for paediatric subgroup analysis. It was not possible to provide a summary estimate of the risk of seizure recurrence beyond these time points as most of the included studies were of short follow-up and too few studies presented recurrence rates at a single time point beyond two years. The evidence presented was found to be of moderate certainty.

AUTHORS' CONCLUSIONS

Despite the limitations of the data (moderate-certainty of evidence), mainly relating to clinical and methodological heterogeneity we have provided summary estimates for the likely risk of seizure recurrence at six months, one year and two years for both children and adults. This provides information that is likely to be useful for the clinician counselling patients (or their parents) on the probable risk of further seizures in the short-term whilst acknowledging the paucity of long-term recurrence data, particularly beyond 10 years.

Seizures in the Emergency Department: clinical and diagnostic data from a series of 153 patients

INTRODUCTION

Seizures are a frequent reason for admission to emergency departments and require early, precise diagnosis and treatment. The objective of this study was to describe the clinical and prognostic characteristics of a series of patients with seizures attended at our hospital's emergency department.

METHODS

We performed a retrospective, observational study of all patients with seizures who were admitted to our hospital's emergency department and attended by the on-call neurology service between February and August 2017.

RESULTS

We included 153 patients, representing 9.9% of all neurological emergency department admissions. The median age was 58 years, 52.3% of patients were women, and 51% had history of epilepsy. Onset was focal in 82.4% of cases, and the most frequent aetiology was cerebrovascular disease (24.2%). Twelve patients (7.8%) developed status epilepticus, which was associated with higher scores on the ADAN scale (P < .001) and with history of refractory epilepsy (P = .002). The in-hospital mortality rate was 3.7%, and in-hospital mortality was associated with older age (P = .049) and status epilepticus (P = .018). Eighty percent of patients with no history of epilepsy were diagnosed with epilepsy at the emergency department; all started treatment. The kappa coefficient for epilepsy diagnosis in the emergency department compared to diagnosis after one year of follow-up by the epilepsy unit was 0.45 (diagnosis was modified in 20% of patients).

CONCLUSIONS

Seizures are a frequent neurological emergency with potential complications and considerable morbidity and mortality rates. In patients with no known history of epilepsy, the condition may be diagnosed in the emergency department, but follow-up at specialised epilepsy units is recommended.

Neuroimaging for differential diagnosis of transient neurological attacks

BACKGROUND

Rapid yet comprehensive neuroimaging protocols are required for patients with suspected acute stroke. However, stroke mimics can account for approximately one in five clinically diagnosed acute ischemic strokes and the rate of thrombolyzed mimics can be as high as 17%. Therefore, to accurately determine the diagnosis and differentiate mimics from true transient ischemic attacks, acute ischemic stroke is a challenge to every clinician.

DISCUSSION

Medical history and neurological examination, noncontract head computed tomography, and routine magnetic resonance imaging play important roles in the assessment and management of patients with transient neurological attacks in the emergency department. This review attempts to summarize how neuroimaging can be utilized to help differentiate the most common mimics from transient ischemic attack and acute ischemic stroke.

CONCLUSION

Although imaging can help direct critical triage decisions for intravenous thrombolysis or endovascular therapy, more detailed medical history and neurological examination are crucial for making a prompt and accurate diagnosis for transient neurological attack patients.

[Inferior temporal electrodes in 24-h EEG]

BACKGROUND

To improve the sensitivity of the EEG in the diagnosis and classification of seizures or epilepsy, long-term recording with inferior temporal electrodes are recommended.

MATERIAL AND METHODS

The spatial distribution of epileptiform discharges from 24‑h EEG with 25 electrodes (10-20, extended by F9/F10, T9/T10, P9/P10) was retrospectively analyzed in 25 cases.

RESULTS

Maximum negativity was located below the 10-20 electrodes in 84%. Epileptiform discharges were more clearly detected on inferior temporal electrodes in 64%. In the intention-to-test population of 77 patients the number needed to test with extra electrodes was estimated as 5.

CONCLUSION

Recording EEG with 25 electrodes for 24 h improves the detection and localization of temporal epileptiform discharges also in geriatric patients with suspected nonlesional epilepsy.

How soon should urgent EEG be performed following a first epileptic seizure?

PURPOSE

Patients with a first unprovoked epileptic seizure are often seen in emergency services. Electroencephalography (EEG) is indicated for diagnosing epilepsy, but the optimal time to perform this test has not been defined. This study aimed to determine the time interval following a seizure within which EEG has the greatest diagnostic yield.

METHODS

We conducted a retrospective study of all adult patients with a first unprovoked seizure who had undergone emergency EEG (July 2014-December 2019). Data collection included demographics, seizure type, time interval to EEG study, EEG pattern identified, and the prescription after emergency assessment. An optimal cut-off point for time to EEG was obtained, and an adjusted regression model was performed to establish associations with the presence of epileptiform abnormalities.

RESULTS

A total of 170 patients were included (mean age: 50.7 years, 40.6% women). Epileptiform discharges were identified in 34.1% of recordings, nonepileptiform abnormalities in 46.5%, and normal findings in 19.4%. A lower latency from seizure to EEG was associated with a higher probability of finding epileptiform discharges (median: 12.7 in the epileptiform EEGs vs. 20 h in the nonepileptiform EEGs, p < 0.001). The time interval associated with the highest probability of detecting an epileptiform EEG pattern was within the first 16 h after seizure onset: 52.1% of recordings performed before the 16-h cut-off showed these abnormal patterns compared with 20.2% performed after (p < 0.001). These findings were not related to the presence of an epileptogenic lesion in neuroimaging or to other clinical variables. The finding of epileptiform abnormalities was followed by a greater prescription of antiseizure drugs (96.4% vs. 66% in nonepileptiform patterns, p < 0.001).

CONCLUSION

The diagnostic yield of EEG following a first unprovoked epileptic seizure is highest when this test is performed within the first 16 h after onset of the event.

Seizures in the Emergency Department: Clinical and diagnostic data from a series of 153 patients

INTRODUCTION

Seizures are a frequent reason for admission to emergency departments and require early, precise diagnosis and treatment. The objective of this study was to describe the clinical and prognostic characteristics of a series of patients with seizures attended at our hospital's emergency department.

METHODS

We performed a retrospective, observational study of all patients with seizures who were admitted to our hospital's emergency department and attended by the on-call neurology service between February and August 2017.

RESULTS

We included 153 patients, representing 9.9% of all neurological emergency department admissions. The median age was 58 years, 52.3% of patients were women, and 51% had history of epilepsy. Onset was focal in 82.4% of cases, and the most frequent aetiology was cerebrovascular disease (24.2%). Twelve patients (7.8%) developed status epilepticus, which was associated with higher scores on the ADAN scale (P<.001) and with history of refractory epilepsy (P=.002). The in-hospital mortality rate was 3.7%, and in-hospital mortality was associated with older age (P=.049) and status epilepticus (P=.018). Eighty percent of patients with no history of epilepsy were diagnosed with epilepsy at the emergency department; all started treatment. The kappa coefficient for epilepsy diagnosis in the emergency department compared to diagnosis after one year of follow-up by the epilepsy unit was .45 (diagnosis was modified in 20% of patients).

CONCLUSIONS

Seizures are a frequent neurological emergency with potential complications and considerable morbidity and mortality rates. In patients with no known history of epilepsy, the condition may be diagnosed in the emergency department, but follow-up at specialised epilepsy units is recommended.