Clinical Course and Features of Seizures Associated With LGI1-Antibody Encephalitis

Abstract

Objective:To determine risk factors associated with clinical relapses and development of chronic epilepsy in patients with anti-leucine-rich glioma-inactivated 1 (LGI1) IgG encephalitis.Methods:Patients with seizures related to LGI1-antibody encephalitis with ≥ 24 months of follow-up from disease onset were identified in the Mayo Clinic electronic medical record and Neuroimmunology lab records. Charts were reviewed to determine clinical factors, seizure types, imaging, treatment, occurrence of relapse, and outcome. Binary logistic regression analysis was performed to identify predictors of the development of chronic epilepsy. Univariate Cox proportional hazards regression was used to examine the influence of baseline characteristics on relapse risk.Results:Forty-nine patients with LGI1-antibody encephalitis and acute symptomatic seizures were identified. Almost all patients (n=48, 98%) were treated with immunotherapy. Eight had definite, and two had possible chronic epilepsy at last follow-up (10/49, 20.4%). Female sex (P=0.048) and younger age at disease onset (P=0.02) were associated with development of chronic epilepsy. Relapses occurred in 20 (40.8%), with a median time to first relapse of 7.5 months (range 3-94 months). Initial treatment with chronic steroid sparing immunotherapy was associated with reduced risk of relapse (hazards ratio=0.28, 95% CI 0.11-0.73, P=0.009).Conclusions:Chronic epilepsy occurred in 20.4% of our patients with LGI1-antibody encephalitis despite aggressive immunotherapy. Risk factors for chronic epilepsy were female sex and earlier age of onset. Relapses occurred in 40.8% of patients with prolonged follow-up, and chronic steroid sparing immunotherapy was associated with a lower relapse rate.

Long‐term seizure outcomes in patients with autoimmune encephalitis: A prospective observational registry study update

“…Our results are similar to those of a previous study with median follow‐up of 27 months in which 1.1% of patients developed epilepsy after encephalitis resolved, although that study did not clearly define epilepsy 15 . Several studies showed that 20%–37% of patients with anti‐NMDAR, anti‐LGI1, or anti‐GABA B R encephalitis developed persistent seizures or autoimmune epilepsy 13,14,30 …”

All’s well that ends well? Long-term course of a patient with anti-amphiphysin associated limbic encephalitis

“…One explanation for the atypical memory profile could be the crowding hypothesis which describes sacrificing right hemisphere functions in favor of a relative sparing of left-hemispheric functions [12] , [13] . Another explanation might relate to the recurring right mesial temporal lobe inflammation, as indicated by an MRI in 2020.…”

“…Together with the frontotemporal focal EEG slowing since 2018, accentuated anxiety and depressive symptoms, persisting subjective cognitive and sleep problems, we cannot fully exclude a clinical relapse at this point, even though the patient has reported no seizures. Even in so-called monophasic non-paraneoplastic anti-LGI-1 encephalitis, between 35% and 40% of patients relapsed [12] , [13] . Since visual memory is dependent on the functional and structural integrity of the right temporal lobe, the described impairment can indicate a disruption of these structures [14] .…”

Autoimmune Neurological Disorders with IgG4 Antibodies: a Distinct Disease Spectrum with Unique IgG4 Functions Responding to Anti-B Cell Therapies

“…Although some LGI1 antibody-positive patients with epilepsy and especially pain respond to immunotherapies [25,64], greater residual patient-rated impairment was more prominent in CASPR2 antibody patients [63]. In one retrospective series, rituximab was used in some patients with worse outcome and, although used only as second-line therapy, 3 of 4 patients reported improvement [65]. However, the noted increase of LGI1-specific plasmablasts/plasma cells in the CSF of these patients [63] justifies anti-CD19/ CD20-specific immunotherapies.…”