Cognitive Impairment is Associated with Longitudinal Disability in LGI-1-IgG Encephalitis
Albert Aboseif1, Yadi Li2, Moein Amin3, Brittany Lapin2, Justin Abbatemarco3, Alexander Rae-Grant3, Vineet Punia4, Rachel Galioto3, Amy Kunchok3
1Department of Neurology, 2Center for Outcomes Research and Evaluation, 3Mellen Center for Multiple Sclerosis Treatment and Research, 4Epilepsy Center, Cleveland Clinic Foundation
Objective:
To determine predictors of longitudinal clinical outcomes in leucine-rich glioma inactivated-1 immunoglobulin G (LGI-1)-IgG autoimmune encephalitis (AE).
Background:

Longitudinal studies prognosticating outcomes in LGI-1-IgG AE are needed to identify key drivers of disability. We examine disability utilizing modified Rankin Scale (mRS) and an AE specific scale, the clinical assessment scale in AE (CASE).

Design/Methods:

A retrospective observational study of seropositive LGI-1-IgG AE patients was conducted between 2013-2022. Clinical predictors included demographics, clinical and paraclinical data, magnetic resonance imaging (MRI), and Montreal Cognitive Assessment (MoCA). Clinical outcomes included mRS and CASE scores. Logistic and linear regressions were used for modeling mRS and CASE, respectively. Baseline clinical characteristics were included as independent variables in the regression models.

Results:

Thirty patients (60% male, median age=69.5; IQR=63.0-76.0) were included, with a median follow-up time of 8.7 months (IQR=4.3-24.1). Seizures (29, [96.7%]), and cognitive impairment (CI) (30, [100%]) were present in the majority. Median initial MoCA was 23/30 (IQR=21.0-25.0). The majority received acute immunotherapy (27, [90%]), and maintenance immunotherapy, (26 [86.7%]). Baseline mRS (median=2.0, IQR=2.0-3.0) and CASE (mean=4.3, SD=3.7) correlated with each other (r=0.58, P<.001) and with initial MoCA score (mRS r=-0.60, P=.009, CASE r=-0.51, P=.031). After 12 months from symptom onset, mRS (OR=0.88, [CI=0.82-0.94], P<.001) and CASE (β=-0.03, [SE=0.01], P<.001) decreased significantly. Temporal lobe(s) Fluid Attenuation Inversion Recovery (FLAIR) hyperintensity correlated with higher mRS longitudinally (OR=17.49, [CI=2.37, 129.05], P=.005). Higher initial MOCA was associated with lower mRS (OR=0.66, [CI=0.45-0.98], P=.04) and CASE (β=-0.24, [SE=0.13], P=.061) longitudinally. At last follow-up, most patients had ongoing cognitive symptoms (25, [83.3%]), while few had ongoing seizure activity (3, [10%]).  

Conclusions:

CI is associated with disability at baseline and long-term follow up, underscoring cognition as an important determinant of disability outcomes in LGI-1-IgG AE. Severity of CI on baseline MoCA may offer prognostic information on long-term disability.

10.1212/WNL.0000000000203346