Autoimmune encephalitis: Early and late findings on serial MR imaging and correlation to treatment timepoints

Introduction

MRI is negative in a large percentage of autoimmune encephalitis cases or lacks findings specific to an antibody. Even rarer is literature correlating the evolution of imaging findings with treatment timepoints. We aim to characterize imaging findings in autoimmune encephalitis at presentation and on follow up correlated with treatment timepoints for this rare disease.

Methods

A full-text radiological information system search was performed for "autoimmune encephalitis" between January 2012 and June 2022. Patients with laboratory-identified autoantibodies were included. MRI findings were assessed in correlation to treatment timepoints by two readers in consensus. For statistical analysis, cell-surface vs intracellular antibody groups were assessed for the presence of early limbic, early extralimbic, late limbic, and late extralimbic findings using the χ2 test.

Results

Thirty-seven patients (female n = 18, median age 58.8 years; range 25.7 to 82.7 years) with 15 different autoantibodies were included in the study. Twenty-three (62%) patients were MRI-negative at time of presentation; 5 of these developed MRI findings on short-term follow up. Of the 19 patients with early MRI findings, 9 (47%) demonstrated improvement upon treatment initiation (7/9 cell-surface group). There was a significant difference (p = 0.046) between the MRI spectrum of cell-surface vs intracellular antibody syndromes as cell-surface antibody syndromes demonstrated more early classic findings of limbic encephalitis and intracellular antibody syndromes demonstrated more late extralimbic abnormalities.

Conclusion

MRI can be used to help narrow the differential diagnosis in autoimmune encephalitis and can be used as a monitoring tool for certain subtypes of this rare disease.

Association of Mortality and Risk of Epilepsy With Type of Acute Symptomatic Seizure After Ischemic Stroke and an Updated Prognostic Model

Importance

Acute symptomatic seizures occurring within 7 days after ischemic stroke may be associated with an increased mortality and risk of epilepsy. It is unknown whether the type of acute symptomatic seizure influences this risk.

Objective

To compare mortality and risk of epilepsy following different types of acute symptomatic seizures.

Design, Setting, and Participants

This cohort study analyzed data acquired from 2002 to 2019 from 9 tertiary referral centers. The derivation cohort included adults from 7 cohorts and 2 case-control studies with neuroimaging-confirmed ischemic stroke and without a history of seizures. Replication in 3 separate cohorts included adults with acute symptomatic status epilepticus after neuroimaging-confirmed ischemic stroke. The final data analysis was performed in July 2022.

Exposures

Type of acute symptomatic seizure.

Main Outcomes and Measures

All-cause mortality and epilepsy (at least 1 unprovoked seizure presenting >7 days after stroke).

Results

A total of 4552 adults were included in the derivation cohort (2547 male participants [56%]; 2005 female [44%]; median age, 73 years [IQR, 62-81]). Acute symptomatic seizures occurred in 226 individuals (5%), of whom 8 (0.2%) presented with status epilepticus. In patients with acute symptomatic status epilepticus, 10-year mortality was 79% compared with 30% in those with short acute symptomatic seizures and 11% in those without seizures. The 10-year risk of epilepsy in stroke survivors with acute symptomatic status epilepticus was 81%, compared with 40% in survivors with short acute symptomatic seizures and 13% in survivors without seizures. In a replication cohort of 39 individuals with acute symptomatic status epilepticus after ischemic stroke (24 female; median age, 78 years), the 10-year risk of mortality and epilepsy was 76% and 88%, respectively. We updated a previously described prognostic model (SeLECT 2.0) with the type of acute symptomatic seizures as a covariate. SeLECT 2.0 successfully captured cases at high risk of poststroke epilepsy.

Conclusions and Relevance

In this study, individuals with stroke and acute symptomatic seizures presenting as status epilepticus had a higher mortality and risk of epilepsy compared with those with short acute symptomatic seizures or no seizures. The SeLECT 2.0 prognostic model adequately reflected the risk of epilepsy in high-risk cases and may inform decisions on the continuation of antiseizure medication treatment and the methods and frequency of follow-up.

Prognostic value of self-reported subjective exercise capacity in patients with acute dyspnea

Background

Quantitative assessment of self-reported exercise capacity as provided by the Duke Activity Status Index (DASI) is a validated measure of exercise capacity in stable ambulatory patients.

Objectives

This study aimedto test whether the quantification of self-reported exercise capacityusing the DASI may aid physicians in the risk stratification of patients presenting with acute dyspnea to the emergency department (ED).

Methods

Basics in Acute Shortness of Breath EvaLuation (BASEL V) was a prospective cohort study recruiting dyspneic patients at the ED. The prognostic value and accuracy of theDASI assessed shortly after presentation were quantified using Cox regression analyses and the Area under the curve (AUC).

Results

Among 1019 patients eligible for this analysis 529 (51.9%) had an adjudicated final diagnosis of acute heart failure, 75 (7.4%) and 297 (29.1%) patients died within 90 and 720 days after presentation. Unadjusted hazard ratios (HR) and multivariable adjusted hazard ratios (aHR) for 90-day and 720-day mortality increased continuously from the fourth (best self-reported exercise capacity) to the first DASI-quartile (worst self-reported exercise capacity). For 720-day mortality in the first quartile theHR was 9.1 (95%-CI 5.5–14.9) (aHR 6.1 [95%-CI 3.7–10.1]), in the second quartile 6.4 (95%-CI 3.9–10.6) (aHR 4.4 [95%-CI 2.6–7.3]), while in the third quartile the HR was 3.2 (95%-CI 1.9–5.5) (aHR 2.4 [95%-CI 1.4–4.0]). The prognostic accuracy of the DASI was moderate-to-high and higher than that of B-type natriuretic peptide (BNP) and NT-proBNP (N-terminal pro-BNP) concentrations, e.g. for 720-day mortality prediction AUC 0.70 versus 0.64, p=0.020; 0.72 versus 0.68, p=0.074.

Conclusions

Quantification of self-reported subjective exercise capacityusing the DASI provides moderate-to-high prognostic accuracy in patients presenting with acute dyspnea to the ED and may aid physicians in further risk stratification.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union, the Swiss National Science Foundation. Duke Activity Status Index