Association of ictal imaging changes in status epilepticus and neurological deterioration

Seizure recurrences in generalized convulsive status epilepticus under sedation: What are its predictors and its impact on outcome?

BACKGROUND

Management of status epilepticus (SE) is focused on the early seizure termination. Refractory SE is an indication for sedation in patients with SE, but up to 75% of patients may be ventilated due to a neurological or respiratory failure. In patients requiring sedation, the clinical assessment is not sufficient to assess seizure control. Identifying those at risk of recurrent seizures could be useful to adapt their management. On the other hand, patients with low risk could benefit from an early withdrawal of sedation to avoid the impact of inappropriate sedation on outcome.

OBJECTIVE

To determine the prevalence and the predictors of uncontrolled SE and its impact on outcome in patients with generalized convulsive SE (GCSE) requiring mechanical ventilation (MV).

METHODS

We retrospectively included patients admitted to the intensive care unit with GCSE requiring MV. Uncontrolled SE was defined as persistent or recurrent seizures during sedation or within 24hours following withdrawal. A multivariable logistic regression model was used to assess the associated factors.

RESULTS

Uncontrolled SE occurred in 37 out of 220 patients (17%). Persistent seizures at admission, higher SAPS II and central nervous system infection were associated with a higher risk of uncontrolled SE. Acute toxic or metabolic etiologies were associated with a decreased risk of uncontrolled SE. In a supplementary analysis, decrease of albumin blood levels was associated with uncontrolled SE. Uncontrolled SE was associated with a poor functional outcome and mortality at 90 days.

CONCLUSIONS

Seventeen percent of patients with a GCSE requiring MV suffered from uncontrolled SE. Etiology and persistent seizures at admission were the main predictors of uncontrolled SE. Patients with uncontrolled SE had a longer duration of sedation and MV, a poor functional outcome and a higher mortality. Further studies are required to determine the impact of continuous electroencephalogram monitoring on the clinical course.

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.

Brain MRI in status epilepticus: Relevance of findings

Status epilepticus (SE) represents one of the most common neurological emergencies, associated with high mortality and an important risk of functional sequelae in survivors. Magnetic resonance imaging (MRI) offers the possibility of early and noninvasive observation of seizure-induced parenchymal disturbances secondary to the epileptic process. In the present review, we propose a descriptive and comprehensive understanding of current knowledge concerning seizure-induced MRI abnormalities in SE, also called peri-ictal MRI abnormalities (PMAs). We then discuss how PMAs, as a noninvasive biomarker, could be helpful to optimize patient prognostication in SE management. Finally, we discuss alternative promising MRI approaches, including arterial spin labeling (ASL), susceptibility-weighted imaging (SWI), dynamic contrast-enhanced (DCE) MRI and dynamic susceptibility contrast (DSC) MRI that could refine our understanding of SE, particularly in non-convulsive form.

Status epilepticus in BRAF-related cardio-facio-cutaneous syndrome: Focus on neuroimaging clues to physiopathology

OBJECTIVE

Cardio-facio-cutaneous syndrome (CFC) is a genetic disorder due to variants affecting genes coding key proteins of the Ras/MAPK signaling pathway. Among the different features of CFC, neurological involvement, including cerebral malformations and epilepsy, represents a common and clinically relevant aspect. Status epilepticus (SE) is a recurrent feature, especially in a specific subgroup of CFC patients with developmental and epileptic encephalopathy (DEE) and history of severe pharmacoresistant epilepsy. Here we dissect the features of SE in CFC patients with a particular focus on longitudinal magnetic resonance imaging (MRI) findings to identify clinical-radiological patterns and discuss the underlying physiopathology.

METHODS

We retrospectively analyzed clinical, electroencephalogram (EEG), and MRI data collected in a single center from a cohort of 23 patients with CFC carrying pathogenic BRAF variants who experienced SE during a 5-year period.

RESULTS

Seven episodes of SE were documented in 5 CFC patients who underwent EEG and MRI at baseline. MRI was performed during SE/within 72 hours from SE termination in 5/7 events. Acute/early post-ictal MRI findings showed heterogenous abnormalities: restricted diffusion in 2/7, focal area of pcASL perfusion change in 2/7, focal cortical T2/FLAIR hyperintensity in 2/7. Follow-up images were available for 4/7 SE. No acute changes were detected in 2/7 (MRI performed 4 days after SE termination).

SIGNIFICANCE

Acute focal neuroimaging changes concomitant with ictal EEG focus were present in 5/7 episodes, though with different findings. The heterogeneous patterns suggest different contributing factors, possibly including the presence of focal cortical malformations and autoinflammation. When cytotoxic edema is revealed by MRI, it can be followed by permanent structural damage, as already observed in other genetic conditions. A better understanding of the physiopathology will provide access to targeted treatments allowing to prevent long-term adverse neurological outcome.

PLAIN LANGUAGE SUMMARY

Cardio-facio-cutaneous syndrome is a genetic disorder that often causes prolonged seizures known as status epilepticus. This study has a focus on electroclinical and neuroimaging patterns in patients with cardio-facio-cutaneous syndrome. During these status epilepticus episodes, we found different abnormal brain imaging patterns in patients, indicating various causes like brain malformations and inflammation. Understanding these patterns could help doctors find specific treatments, protecting cardio-facio-cutaneous syndrome patients from long-term brain damage.

Magnetic Resonance Imaging in Status Epilepticus: Useful Scrying Board or Expensive Stopwatch?

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Clinical scores and clusters for prediction of outcomes in status epilepticus

Status epilepticus (SE) is a life-threatening condition and may have long-term negative sequelae. Short- and long-term outcomes encompass mortality, deterioration of functional status compared to baseline, refractoriness to treatment, recurrence of SE, and development of epilepsy, cognitive impairment, and behavioral disturbances. So far, the greatest amount of evidence is available for the prediction of short-term mortality. Conversely, the knowledge regarding long-term consequences among SE survivors is still scarce and several issues have not yet been resolved. The heterogeneity of SE renders the prognostication of outcomes challenging. Although aetiology is the main determinant of the outcome, different prognostic predictors have been identified. In this regard, data on group effects need to be integrated into prognostic scores to allow individual risk stratification. Importantly, many of the present scores are not designed to enable repetition to follow patient evolution. A new paradigm for the assessment of SE outcomes should consider variables that become available and/or can be retested during the course of SE. Neuroimaging findings, serum biomarkers, treatment characteristics, complications during SE, peri-ictal and postictal characteristics after SE cessation look as promising determinants of outcome and are suitable for inclusion in future models to enhance the quality and increase the reliability of prediction. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.