Citations

Background Data regarding long-term recovery from autoimmune encephalitis (AE) remain limited. Methods This retrospective observational study investigated outcomes in 182 patients who met the 2016 criteria for definite AE. Recovery data were available in 172 patients. Follow-up data at ≥24 months post-attack were available for 119. Recovery trajectory, residual symptoms, outcome predictors and causes of post-AE death were assessed. Results Of 172 patients, 138 (80%) achieved good recovery (modified Rankin Scale (mRS) ≤2) with a median recovery time of 4 months (95% CI: 2 to 6 months). Recovery varied by associated neural antibody, with the best recovery observed in leucine-rich glioma-inactivated 1 (97% good recovery, median recovery time 0 (0 to 2) months). Paraneoplastic AE (p=0.007), severe attacks (eg, mRS ≥4 at attack, p=0.007) and cerebrospinal fluid pleocytosis (p=0.005) were associated with a lower likelihood of good recovery, while seizure presentation (p=0.026) was associated with better recovery. Despite good recovery, several residual symptoms persisted ≥24 months post-AE, including cognitive deficits (53%), seizures (26%), depression (23%), sleep disorders (25%), brainstem/cerebellar symptoms (13%), other movement disorders (14%) and autonomic symptoms (12%). Predictors of long-term sequelae included disabling cognitive deficit at onset and delayed immunotherapy for post AE-dementia, and medial temporal atrophy as well as escalation to cyclophosphamide therapy for both drug-resistant epilepsy and chronic depression. Of 182 patients, 20 (11%) died; the most common cause of death was progression of AE (6/20 (30%)). Conclusion While the majority of patients achieved functional independence after AE, several residual symptoms persisted. Several clinical and paraclinical features were associated with long-term sequelae.

AbstractThe aim of this study is to report three cases of epilepsy with eyelid myoclonia (EEM) with CHD2 pathogenic variants. A database of 134 patients with EEM evaluated at Mayo Clinic sites was searched to identify patients with CHD2 variants. The medical records of those identified were reviewed to describe their presentation, treatment, and clinical course. Three patients (2 males, 1 female) with EEM were found to harbor de novo CHD2 pathogenic variants (c.2636C>T p.(Ala879Val), c.3734delA p. (Lys1245Asnfs*4), and c.3896delTinsCG p. (Val1299Alafs*5)). All three patients had comorbid autism spectrum disorder (ASD), intellectual disability (ID), and attention deficit disorder (ADHD). Eyelid myoclonia was a prominent seizure type that persisted in the three patients despite trials of multiple antiseizure medications. Generalized tonic–clonic seizures occurred in two of the patients but were controlled with antiseizure medications. Genetic testing should be considered in patients presenting with EEM, especially when ADHD, ID, ASD, and drug‐resistant seizures are present. Further understanding of the relationship between CHD2 variants and epileptogenesis may provide important insights into the pathogenesis of EEM.

AbstractEpilepsy associated with high‐titer glutamic acid decarboxylase 65 (GAD65) IgG is often refractory to immunotherapies and antiseizure medication. This study sought to determine the efficacy of vagus nerve stimulation (VNS) and surgical resection in patients with drug‐resistant epilepsy associated with GAD65‐IgG. We retrospectively identified 15 patients with drug‐resistant epilepsy and high serum GAD65 antibody titers (>20 nmol·L−1) who underwent VNS implantation (n = 6), surgical resection (n = 7), or both (n = 2). A responder to VNS was defined as someone with a ≥50% reduction in seizure frequency, and a favorable surgical outcome was defined as Engel I–II. Of the eight patients who underwent VNS implantation, three (37.5%) were initially responders, but this was not sustained in two. Of the nine patients who underwent surgical resection, three (33.3%) had a favorable outcome; however, only one patient was seizure‐free at last follow‐up. Pathology was available in six patients, and only one had evidence of inflammation; this patient had seizure onset 1 year prior to surgery. Favorable seizure outcome correlated with older age at time of resective surgery, with a trend favoring later age of seizure onset. Taken together, surgical resection and VNS implantation may have limited efficacy in this patient population but can be considered in carefully selected cases.

AbstractWith the discovery of an expanding number of neural autoantibodies, autoimmune etiologies of seizures have been increasingly recognized. Clinical phenotypes have been identified in association with specific underlying antibodies, allowing an earlier diagnosis. These phenotypes include faciobrachial dystonic seizures with LGI1 encephalitis, neuropsychiatric presentations associated with movement disorders and seizures in NMDA‐receptor encephalitis, and chronic temporal lobe epilepsy in GAD65 neurologic autoimmunity. Prompt recognition of these disorders is important, as some of them are highly responsive to immunotherapy. The response to immunotherapy is highest in patients with encephalitis secondary to antibodies targeting cell surface synaptic antigens. However, the response is less effective in conditions involving antibodies binding intracellular antigens or in Rasmussen syndrome, which are predominantly mediated by cytotoxic T‐cell processes that are associated with irreversible cellular destruction. Autoimmune encephalitides also may have a paraneoplastic etiology, further emphasizing the importance of recognizing these disorders. Finally, autoimmune processes and responses to novel immunotherapies have been reported in new‐onset refractory status epilepticus (NORSE) and febrile infection‐related epilepsy syndrome (FIRES), warranting their inclusion in any current review of autoimmune‐associated seizure disorders.