Clinical characterization of unknown/cryptogenic status epilepticus suspected as encephalitis: A multicenter cohort study

Seizure burden and neuropsychological outcomes of new-onset refractory status epilepticus: Systematic review

Background

Long-term sequelae of the new onset refractory status epilepticus (NORSE) include the development of epilepsy, cognitive deficits, and behavioral disturbances. The prevalence of these complications has been previously highlighted in case reports and case series: however, their full scope has not been comprehensively assessed.

Methods

We conducted a systematic review of the literature (PROSPERO ID CRD42022361142) regarding neurological and functional outcomes of NORSE at 30 days or longer following discharge from the hospital. A systematic review protocol was developed using guidance from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Results

Of the 1,602 records for unique publications, 33 reports on adults and 52 reports on children met our inclusion criteria. They contained the description of 280 adults and 587 children of whom only 75.7 and 85% of patients, respectively had data on long-term follow-up. The mean age of adult and pediatric patients was 34.3 and 7.9 years, respectively; and the longest duration of follow up were 11 and 20 years, respectively. Seizure outcomes received major attention and were highlighted for 93.4 and 96.6% of the adult and pediatric NORSE patients, respectively. Seizures remained medically refractory in 41.1% of adults and 57.7% of children, while seizure freedom was achieved in only 26 and 23.3% of these patients, respectively. The long-term cognitive outcome data was provided for just 10.4% of the adult patients. In contrast, cognitive health data were supplied for 68.9% of the described children of whom 31.9% were moderately or severely disabled. Long-term functional outcomes assessed with various standardized scales were reported in 62.2 and 25.5% of the adults and children, respectively with majority of patients not being able to return to a pre-morbid level of functioning. New onset psychiatric disorders were reported in 3.3% of adults and 11.2% of children recovering from NORSE.

Conclusion

These findings concur with previous observations that the majority of adult and pediatric patients continue to experience recurrent seizures and suffer from refractory epilepsy. Moderate to severe cognitive disability, loss of functional independence, and psychiatric disorders represent a hallmark of chronic NORSE signifying the major public health importance of this disorder.

Seizure outcome-related factors in autoimmune encephalitis: A systematic review and meta-analysis

Background

Identifying the predictors for seizure outcome in autoimmune encephalitis (AE) and investigating how to prevent persistent seizures would have major clinical benefits effectively. Thus, we aimed to perform a systematic review and meta-analysis to examine seizure outcome-related factors in AE patients.

Methods

PubMed and EMBASE were systematically searched from inception to 10 June 2022 for studies investigating seizure outcome-related factors in AE. The pooled effect estimates, including standardized mean differences (SMDs) and odds ratios (ORs) with 95% confidence intervals (CIs), were calculated to estimate the effect of each included factor on the seizure outcome.

Results

A total of 10 studies were included in the meta-analysis. Our pooled results of this meta-analysis showed that five factors were found to increase the risk of persistent seizures in AE patients, including onset with seizures (OR = 2.106, 95% CI = 1.262–3.514, p = 0.004), status epilepticus (OR = 3.017, 95% CI = 1.995–4.563, p < 0.001), EEG abnormalities (OR = 1.581, 95% CI = 1.016–2.46, p = 0.042), MRI abnormalities (OR = 1.554, 95% CI = 1.044–2.283, p = 0.03), and longer time from clinical onset to immunotherapy (SMD = 1.887, 95% CI = 0.598–3.156, p = 0.004).

Conclusion

Our meta-analysis indicated that onset with seizures, status epilepticus, EEG abnormalities, MRI abnormalities, and longer time from clinical onset to immunotherapy were risk factors for persistent seizures in AE patients.

Association between autoimmune encephalitis and epilepsy: Systematic review and meta-analysis

BACKGROUND

Diverse neuronal antibodies are related to autoimmune encephalitis (AE) and AE-related epilepsy. However, the epidemiological characteristics of AE, AE-associated antibodies, and AE-related seizures are still unclear.

AIMS

This research evaluated the relationship between AE, AE-related seizures, and neuronal antibodies, as well as the morbidity of AE with early incidence.

METHODS

The PubMed, Embase, Cochrane, and Web of Science databases were searched. Pooled estimates and 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

Of the 4,869 citations identified, 100 articles were reviewed in full, and 42 subgroups were analyzed. The overall incidence of AE patients with seizures was 42% (95% CI: 0.40-0.44), and among them, the incidence of epilepsy in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis patients was 73% (95% CI: 0.70-0.77). Subsequently, we found that the prevalence of AE as the cause of epilepsy within the pooled period was 1% (95% CI: 0.01-0.02), while the overall positive rate of neuronal antibodies in epilepsy patients was 4% (95% CI: 0.03-0.05). Additionally, the detection rates of different antibodies among epilepsy patients were as follows: anti-NMDAR, 1%; anti-leucine-rich glioma inactivated 1 (LGI1), 1%; anti-contactin-associated protein-like 2 (CASPR2), 2%.

CONCLUSION

Based on our findings, neuronal antibodies may serve as a bridge to study AE and immune-related epilepsy. To further understand the differences in outcomes following different treatment measures, and to provide more information for public health policy and prevention, more research is needed to improve the accuracy of estimations.

Characteristics and outcome-related factors of seizure at the first onset of autoimmune encephalitis: A retrospective study

Aims

Seizure outcome of autoimmune encephalitis (AE) varies from seizure‐free to refractory epilepsy, and the associated factors remain unclear. We aimed to describe seizure characteristics, identify seizure outcome‐related factors, and discuss the medication strategy of antiepileptic drugs (AEDs) at the first onset of AE.

Methods

We retrospectively studied the data of 86 patients with clinically diagnosed AE. The clinical characteristics were described using a chi‐square test. Seizure outcome‐related factors were assessed using multivariable logistic regression analysis.

Results

56 patients were finally enrolled, with antibodies to N‐methyl‐D‐aspartate receptor found in 29, to γ‐aminobutyric acid receptor B found in 13, and to leucine‐rich glioma‐inactivated protein 1 found in 14. Status epilepticus occurrence and onset with seizure lead to a poor seizure outcome, while administration of human gamma globulin and a low antibody titer contributed to a good seizure outcome.

Conclusions

In the acute phase, seizure characteristics may be considered in the utilization of AEDs. For patients with seizure‐free status in the acute phase, clinical manifestation (onset with seizure or not, whether status epilepticus occurs or not), therapy regimen (human gamma globulin administered or not), and antibody titer may be considered when formulating the strategy for withdrawal of AEDs post‐acute phase.

Autoantibody-Mediated Encephalitis

BACKGROUND

Acute and subacute disturbances of wakefulness and cognitive function are common neurological manifestations in the hospital and in outpatient care. An important element of the differential diagnosis was described only a few years ago: autoimmune encephalitis, a condition whose diagnosis and treatment pose an interdisciplinary challenge.

METHODS

This review is based on pertinent publications from the years 2005-2017 that were retrieved by a selective search in PubMed, and on the authors' personal experience and case reports.

RESULTS

The incidence of autoimmune encephalitis in Germany is estimated at 8-15 cases per million persons per year. In some patients with psychotic manifestations or impaired consciousness of acute or subacute onset, an autoimmune patho - genesis can be demonstrated by the laboratory detection of autoantibodies against neuronal target antigens (e.g., glutamate receptors). Testing of this type should be performed in patients with inflammatory changes in the cerebrospinal fluid or on magnetic resonance imaging (MRI), or those who have had an otherwise unexplained first epileptic seizure or status epilepticus. The cumulative sensitivity of testing for all potentially causative antineuronal antibodies in patients with clinically defined autoimmune encephalitis is estimated at 60-80 %. Figures on cumulative specificity are currently unavailable.

CONCLUSION

The detection of antineuronal antibodies in patients with the corresponding appropriate symptoms implies the diagnosis of autoimmune encephalitis. Observational studies have shown that rapidly initiated immunosuppressive treatment improves these patients' outcomes. Further studies are needed to determine the positive predictive value of antineuronal antibody detection and to develop further treatment options under randomized and controlled conditions.

Prevention, Treatment, and Monitoring of Seizures in the Intensive Care Unit

The diagnosis and management of seizures in the critically ill patient can sometimes present a unique challenge for practitioners due to lack of exposure and complex patient comorbidities. The reported incidence varies between 8% and 34% of critically ill patients, with many patients often showing no overt clinical signs of seizures. Outcomes in patients with unidentified seizure activity tend to be poor, and mortality significantly increases in those who have seizure activity longer than 30 min. Prompt diagnosis and provision of medical therapy are crucial in order to attain successful seizure termination and prevent poor outcomes. In this article, we review the epidemiology and pathophysiology of seizures in the critically ill, various seizure monitoring modalities, and recommended medical therapy.

Seizure characteristics, treatment, and outcome in autoimmune synaptic encephalitis: A long-term study

OBJECTIVES

The objective of this study was to report seizure characteristics, long-term outcome, and potential factors associated with persistent seizures in patients with autoimmune synaptic encephalitis (ASE).

METHOD

Clinical data and courses of 52 patients with ASE who presented with seizures at the Department of Neurology of the First Hospital of Jilin University from January 2015 to August 2017 were reviewed. Seizure outcomes were assessed with a median follow-up duration of 30 months (8-40 months).

RESULTS

Most patients (71.2%) presented with seizure at initial consultation; focal to bilateral tonic-clonic seizures (50.0%) were the most common type. The temporal lobe (73.5%) was the prominent region of seizure origin, which was incident with hippocampal lesions on magnetic resonance imaging (MRI) in 62.1% of the patients. Status epilepticus, subclinical seizures, and nonepileptic events were observed in 28.9%, 36.8%, and 28.9% of the patients, respectively. Twenty-seven out of the 43 followed-up patients (62.8%) exhibited seizure remission after initial immunotherapy. Others (37.2%) developed persistent seizures to different extents. Six out of 9 patients experienced additional seizure freedom because of antiepileptic drugs (AEDs); however, the seizures of the other three patients, with serious conditions, showed poor response. Patients with anti-N-methyl-d-aspartate receptor antibodies had a lower risk of developing persistent seizures than those with anti-leucine-rich glioma-inactivated 1 (LGI1) or anti-γ-aminobutyric acid receptor type B receptor (GABA_BR) antibodies (P = 0.001).

CONCLUSIONS

A complex of clinical and subclinical seizures, and nonepileptic events characterize ASE. Patients with anti-LGI1 or anti-GABA_BR antibodies have a higher risk of developing persistent seizures; AEDs are suitable for achieving additional seizure freedom, but not for patients with serious conditions. A few patients present with super-refractory epilepsy despite multiple treatments.

The Different Clinical Features Between Autoimmune and Infectious Status Epilepticus

Objective: The prognosis of status epilepticus (SE) is highly related to the underlying etiology. Inflammation of the central nervous system (CNS), including infection and autoimmune encephalitis, is one of the treatable conditions causing SE. The initial presentation of infectious and autoimmune CNS disorders can be quite similar, which may be difficult to differentiate at the beginning. However, treatment for these entities can be quite different. In this study, we aim to identify the differences in clinical features among patients with infectious and autoimmune SE, which could help the clinicians to select initial investigation and ensuing therapies that may improve overall outcomes.

Methods: This was a retrospective study that included 501 patients with SE within a period of 10.5-years. Patients with inflammatory etiology were collected and separated into infectious and autoimmune SE. The symptoms at onset, SE semiology, status epilepticus severity score, and END-IT score at admission, treatment for SE, and outcome (modified Rankin Scale) on discharge and last follow-up were recorded. Data on the first cerebrospinal fluid, electroencephalography, and magnetic resonance imaging were also collected.

Results: Forty-six (9.2%) of the 501 patients had SE with inflammatory etiology. Twenty-five (5%) patients were autoimmune SE and 21 (4.2%) were infectious SE. Patients with autoimmune SE have younger age and female predominance. As for clinical presentations, psychosis, non-convulsive SE, and super refractory SE were more common in patients with autoimmune SE. Nevertheless, the prognosis showed no difference between the two groups.

Conclusion: The different initial clinical presentations and patient characteristics may provide some clues about the underlying etiology of SE. When inflammatory etiology is suspected in patients with SE, younger age, female sex, psychosis, non-convulsive SE, and super refractory SE are clinical features that suggest an autoimmune etiology.