Salzburg consensus criteria are associated with long-term outcome after non-convulsive status epilepticus

Postictal Encephalopathy After Status Epilepticus: Outcome and Risk Factors

BACKGROUND

Postictal encephalopathy is well known after status epilepticus (SE), but its prognostic impact and triggers are unknown. Here, we aimed to establish risk factors for the development of postictal encephalopathy and to study its impact on survival after discharge.

METHODS

This retrospective cohort study comprised adult patients diagnosed with first nonanoxic SE at Odense University Hospital between January 2008 and December 2017. Patients with ongoing SE at discharge or unknown treatment success were excluded. Postictal symptoms of encephalopathy were estimated retrospectively using the West Haven Criteria (WHC). WHC grade was determined for postictal day 1 to 14 or until the patient died or was discharged from the hospital. Cumulative postictal WHC during 14 days after SE-cessation was used to quantify postictal encephalopathy. Clinical characteristics, patient demographics, electroencephalographic and imaging features, and details on intensive care treatment were assessed from medical records.

RESULTS

Of all eligible patients (n = 232), 198 (85.3%) had at least WHC grade 2 postictal encephalopathy that lasted for > 14 days in 24.5% of the surviving patients. WHC grade at discharge was strongly associated with poor long-term survival (p < 0.001). Postictal encephalopathy was not associated with nonconvulsive SE, postictal changes on magnetic resonance imaging, or distinct ictal patterns on electroencephalography. Although duration of SE and treatment in the intensive care unit showed an association with cumulative postictal WHC grade, they were not independently associated with the degree of encephalopathy when controlling for confounders. In a linear regression model, etiology, duration of sedation, age, and premorbid modified Rankin Scale were significant and consistent predictors for higher cumulative postictal WHC grade. Exploratory analyses showed an association of a cumulative midazolam dosage (mg/kg/h) with higher cumulative postictal WHC grade.

DISCUSSION

In this cohort, postictal encephalopathy after SE was common and associated with poor long-term survival. Seizure characteristics were not independently associated with postictal encephalopathy; the underlying etiology, long (high-dose midazolam) sedation, high age, and poor premorbid condition were the major risk factors for its development.

Prognostic value of Salzburg nonconvulsive status epilepticus criteria: The SACE score

OBJECTIVE

This study was undertaken to investigate the association between the Salzburg nonconvulsive status epilepticus (NCSE) criteria and in-hospital outcome, to determine the predictive accuracy of the Status Epilepticus Severity Score (STESS), modified STESS (mSTESS), Epidemiology-Based Mortality Score in Status Epilepticus (EMSE), and END-IT (encephalitis, NCSE, diazepam resistance, imaging features, and tracheal intubation) in NCSE patients, and to develop a new prognostic score specifically designed for NCSE patients.

METHODS

Clinical and electroencephalographic (EEG) data of adult patients treated for NCSE from 2020 to 2023 were retrospectively assessed. Age, sex, modified Rankin Scale at admission, comorbidities, history of seizures, etiology, status epilepticus type, and outcome were collected from the patients' digital charts. EEG data were assessed and categorized applying the Salzburg NCSE criteria. In-hospital death was defined as the primary outcome.

RESULTS

A total of 116 NCSE patients were included. Multivariable logistic regression revealed that Salzburg NCSE criterion A2 (ictal morphological, spatial, and temporal evolution) was associated with in-hospital survival. The best STESS cutoff was ≥4 (sensitivity = .62, specificity = .69, accuracy = 67%). mSTESS ≥ 5 reached a sensitivity of .68, a specificity of .57, and an overall accuracy of 60%, EMSE ≥ 64 a sensitivity of .82, a specificity of .39, and an overall accuracy of 52%, and END-IT ≥ 3 a sensitivity of .65, a specificity of .44, and an overall accuracy of 50%. Through a hypothesis-generating approach, we developed the SACE score, which integrates EEG features (criterion A2) with patient age (with a 75-year cutoff), history of seizures, and level of consciousness. With a cutoff of ≥3, it had a sensitivity of .77, a specificity of .74, and an overall accuracy of 76%, performing better than other prognostic scores.

SIGNIFICANCE

We developed a new user-friendly scoring system, the SACE score, which integrates EEG features with other established outcome-related variables assessable in early stages, to assist neurologists and neurointensivists in making more tailored prognostic decisions for NCSE patients.

Focal nonconvulsive status epilepticus with impaired consciousness in older adults: Prognosis-related variables

OBJECTIVE

To assess the prognosis-related clinical-EEG characteristics in older adults with focal nonconvulsive status epilepticus with impaired consciousness (focal NCSE).

METHODOLOGY

We prospectively assessed clinical variables and EEG data at diagnosis and after an initial pharmacological protocol (within 24 hours) and their relationship with prognosis in older adults with focal NCSE treated at the emergency room.

RESULTS

The clinical presentation of focal NCSE in 45 adults (mean age 73.5 ± 9.1 years) was characterized by decreased consciousness and the presence of subtle ictal phenomena in 24 cases. On the initial EEG, there were lateralized periodic discharges (LPDs) and lateralized rhythmic delta activity (RDA) in 25 cases and epileptiform discharges (EDs > 2.5 Hz) in 32 cases. After the drug protocol, 33 (73.3%) cases had effective clinical improvement. Death after 30 days occurred in 10 (22.2%) cases. In simple and multiple logistic regression, it was observed that older adults with a history of epilepsy/seizures have a greater chance of clinical improvement. The occurrence of death was associated with the presence of RDA in the initial EEG and its subsequent disappearance (OR 6.93, 95% CI 1.20-46.01, p = 0.033). Higher mortality was associated with the presence of LPDs in the initial EEG and with the presence of LPDs/EDs > 2.5 Hz in the EEG after treatment.

CONCLUSION

The presence of ED > 2.5 Hz in the initial EEG was the most frequent pattern at focal NCSE. Clinical improvement was associated with a history of epilepsy/seizures. Mortality in the focal NCSE was high and was associated with the presence of RDA in the initial EEG and the occurrence of LPDs/ED > 2.5 Hz after treatment.

Nonconvulsive status epilepticus characteristics in glioma patients: a retrospective study

PURPOSE

Epilepsy is a common complication of gliomas. The diagnosis of nonconvulsive status epilepticus (NCSE) is challenging because it causes impaired consciousness and mimics glioma progression. NCSE complication rate in the general brain tumor patient population is approximately 2%. However, there are no reports focusing on NCSE in glioma patient population. This study aimed to reveal the epidemiology and features of NCSE in glioma patients to enable appropriate diagnosis.

METHODS

We enrolled 108 consecutive glioma patients (45 female, 63 male) who underwent their first surgery between April 2013 and May 2019 at our institution. We retrospectively investigated glioma patients diagnosed with tumor-related epilepsy (TRE) or NCSE to explore disease frequency of TRE/NCSE and patient background. NCSE treatment approaches and Karnofsky Performance Status Scale (KPS) changes following NCSE were surveyed. NCSE diagnosis was confirmed using the modified Salzburg Consensus Criteria (mSCC).

RESULTS

Sixty-one out of 108 glioma patients experienced TRE (56%), and five (4.6%) were diagnosed with NCSE (2 female, 3 male; mean age, 57 years old; WHO grade II 1, grade III 2, grade IV 2). All NCSE cases were controlled by stage 2 status epilepticus treatment as recommended in the Clinical Practice Guidelines for Epilepsy by the Japan Epilepsy Society. The KPS score significantly decreased after NCSE.

CONCLUSION

Higher prevalence of NCSE in glioma patients was observed. The KPS score significantly decreased after NCSE. Actively taking electroencephalograms analyzed by mSCC may facilitate accurate NCSE diagnosis and improve the activities of daily living in glioma patients.

Do acute EEG findings add to clinical features in predicting outcomes after status epilepticus and acute symptomatic seizures?

Status epilepticus is a potentially life-threatening medical emergency associated with poor functional outcomes. Improving our ability to accurately predict functional outcomes is beneficial to optimizing treatment strategies. Currently, there are four published status epilepticus scores in adults: STESS (Status Epilepticus Severity Score), EMSE (Epidemiology-Based Mortality Score in Status Epilepticus), END-IT (Encephalitis-Nonconvulsive-Diazepam resistance-Imaging-Tracheal intubation), and recently published ACD (Age-level of Consciousness-Duration of status epilepticus) score. The only available scale in the pediatric population is PEDSS (Pediatric CPC scale-EEG (normal vs abnormal)-Drug refractoriness-critical Sickness-Semiology). While these scores are useful research tools, currently there is little evidence to suggest their utility during real-time clinical care. Except for EMSE, none of the scores incorporate EEG findings for prognostication. Adding EEG features improves prognostic accuracy, as has been shown with the EMSE scale with and without the EEG component. Acute symptomatic seizures (AsyS) and early epileptiform abnormalities, especially nonconvulsive seizures, and periodic discharges, markedly increase the risk for subsequent unprovoked seizures. However, many of these patients may not need lifelong anti-seizure medications (ASMs). Continuous EEG monitoring shows that the majority of ASyS are nonconvulsive and can identify epileptic patterns. Dedicated specialty clinics for these patients, known as Post Acute Symptomatic Seizure (PASS) clinics, already exist in the United States. Post Acute Symptomatic Seizure clinics are ideal for both long-term clinical care and answering important research questions related to epileptogenesis, duration of ASM treatment required, and evolution of EEG findings. This topic was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Association of ictal imaging changes in status epilepticus and neurological deterioration

OBJECTIVE

In patients with status epilepticus (SE), the clinical significance of ictal changes on magnetic resonance imaging (MRI) is insufficiently understood. We here studied whether the presence of ictal MRI changes was associated with neurological deterioration at discharge.

METHODS

The retrospective cohort comprised all identifiable patients treated at Odense University Hospital in the period 2008-2017. All amenable MRIs were systemically screened for ictal changes. Patient demographics, electroencephalography, seizure characteristics, treatment, and SE duration were assessed. Neurological status was estimated before and after SE. The predefined endpoint was the association of neurological deterioration and ictal MRI changes.

RESULTS

Of 261 eligible patients, 101 received at least one MRI during SE or within 7 days after cessation; 43.6% (44/101) had SE due to non- or less brain-damaging etiologies. Patients who received MRI had a longer duration of SE, less frequently had a history of epilepsy, and were more likely to have SE due to unknown causes. Basic characteristics (including electroencephalographic features defined by the Salzburg criteria) did not differ between patients with (n = 20) and without (n = 81) ictal MRI changes. Timing of MRI was important; postictal changes were rare within the first 24 h and hardly seen >5 days after cessation of SE. Ictal MRI changes were associated with a higher risk of neurological deterioration at discharge irrespective of etiology. Furthermore, they were associated with a longer duration of SE and higher long-term mortality that reached statistical significance in patients with non- or less brain-damaging etiologies.

SIGNIFICANCE

In this retrospective cohort, ictal changes on MRI were associated with a higher risk of neurological deterioration at discharge and, possibly, with a longer duration of SE and poorer survival.