Citations

Objective To characterize regional brain atrophy patterns, evaluate their association with regional leucine‐rich glioma‐inactivated‐1 ( LGI1 ) gene expression, and identify clinical predictors of hippocampal atrophy in LGI1 autoimmune encephalitis (AE). Methods This study compared regional brain volumes in LGI1‐AE patients versus age‐ and sex‐matched healthy controls (HC) and Alzheimer's disease (AD) patients. LGI1 gene expression was derived from the Allen Human Brain Atlas. Multivariable linear regression and generalized linear models were utilized. Results A total of 55 LGI1‐AE patients were included. Median age was 68 years (IQR 62.5–74.2 years) at volumetric analysis, after 19 months (IQR 11–45 months) from symptom onset. Compared with HC ( n = 55) and AD patients ( n = 55), LGI1‐AE patients had greater regional atrophy of the hippocampus, insula, caudate, and putamen ( p < 0.002). Longitudinal analyses demonstrated hippocampal and pallidal atrophy after covariate adjustment. Among those who did not fulfill limbic encephalitis criteria and/or had non‐lesional magnetic resonance imaging, limbic and striatal atrophy were identified compared with HC ( p < 0.01). Regions with the greatest differential atrophy corresponded to higher LGI1 gene expression (Spearman ρ = 0.7, p = 0.005). Severe cognitive deficits at diagnosis ( β = −0.56; p = 0.002) and longer disease duration ( β = −0.01; p = 0.001) independently predicted total hippocampal volume ( R 2 = 0.31). Interpretation LGI1‐AE demonstrates a distinct pattern of limbic and striatal atrophy that differs from AD and aligns with regional LGI1 expression, supporting a model of selective network vulnerability. Greater baseline cognitive impairment and longer disease duration independently associated with hippocampal atrophy, underscoring the potential importance of early diagnosis and treatment to limit structural brain injury. ANN NEUROL 2026

Immune-mediated epilepsies represent an etiologically unique category defined by immune activation within the central nervous system that initiates a pathophysiological cascade resulting in seizures, encephalopathy, and sometimes epileptogenesis with long-term epilepsy. Once considered rare and largely confined to paraneoplastic or postinfectious syndromes, immune-mediated and inflammatory mechanisms are now recognized across a broad spectrum ranging from acute autoimmune encephalitis with reversible seizures, new-onset refractory status epilepticus, or febrile illness-related refractory status epilepticus, to chronic autoimmune-associated epilepsy and drug-refractory structural epilepsies. This review integrates historical perspectives, mechanistic insights from animal and human studies, and contemporary clinical frameworks. It synthesizes advances in neuroimmunology, clinical phenotyping, diagnostics, immunomodulatory and antiseizure therapies, neuromodulation, and patient and family centered outcomes, and outlines future directions focused on biomarker-driven precision medicine, disease-modifying strategies, and interdisciplinary care models.

This Viewpoint discusses the discovery of numerous neuronal autoantibodies and how autoimmune encephalitis is diagnosed and treated.

Leucine-rich glioma-inactivated-1 (LGI1) IgG-associated autoimmune encephalitis typically presents with faciobrachial dystonic seizures, hyponatremia, and temporal lobe MRI abnormalities. However, the clinical spectrum of LGI1 IgG-associated AE extends beyond these classical features, with reports of diverse seizure semiologies and atypical presentations challenging traditional diagnostic paradigms. This study reports a male in his late 60s presenting with recurrent episodes of right foot cramping and electric shock-like pain, progressing to generalized tonic-clonic seizures. Initial workup suggested chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), but LGI1 IgG antibodies were subsequently detected. Despite treatment with intravenous immunoglobulin (IVIG), the seizures persisted. This case highlights the heterogeneity in LGI1 encephalitis presentations. The patient’s proprioceptive-induced reflex seizures represent a rare manifestation of the disease. Treatment with rituximab, a B-cell depleting therapy, resulted in significant improvement, suggesting its potential effectiveness in LGI1 encephalitis with a resistant seizure course. The case also emphasizes the intricate interplay between the mesial temporal lobe, basal ganglia, and frontal regions in LGI1 encephalitis pathophysiology.

Objective: To describe cochlear implant outcomes in a patient with bilateral rapidly progressive hearing loss secondary to Kelch-like protein–11 (KLHL11) IgG rhombencephalitis. Patient: A 26-year-old male presenting to neurotology clinic at a tertiary care center for evaluation of bilateral rapidly progressive sensorineural hearing loss, unresponsive to systemic corticosteroid therapy. Interventions: Bilateral simultaneous cochlear implantation. Main Outcome Measures: Postimplant speech testing (CNC word, AzBio sentence scoring), and changes to hearing function with fluctuations in systemic disease symptomatology. Results: Preoperative testing demonstrated poor speech perception (bilateral AzBio sentence in quiet: 43%, right-sided CNCw score: 38%, and left-sided CNCw score: 0%). Despite systemic disease progression of KLHL11-IgG rhombencephalitis, including worsening cerebellar ataxia and dysarthria, cochlear implant performance did not decrease at the time of last follow-up. At 1-year, binaural and monaural speech testing were both significantly improved compared with the 1-month testing (bilateral AzBio sentence in quiet: 91%, right-sided CNCw score: 70%, and left-sided CNCw score: 32%). Conclusions: Cochlear implantation may offer meaningful auditory rehabilitation in patients with KLHL11-IgG associated rhombencephalitis with relative auditory nerve sparing, despite ongoing disease progression. Further studies are required to evaluate the durability and generalizability of cochlear implantation across the spectrum of disease-related hearing loss.

Gephyrin is a postsynaptic scaffold protein essential for inhibitory neurotransmission. Gephyrin‐immunoglobulin G (IgG) was reported, decades ago, in a single case of paraneoplastic stiff‐person‐like syndrome, but its broader clinical relevance remains unknown. While investigating unclassified synaptic IgGs mimicking amphiphysin‐IgG, we identified gephyrin‐IgG in 3 patients using human protein microarray. Gephyrin specificity was confirmed using confocal tissue‐based immunofluorescence assay, cell‐based assay, and Western blot. The 3 patients, all female, had: encephalitis (2) and myeloneuropathy and breast cancer (1). All had inflammatory cerebrospinal fluid and abnormal magnetic resonance imaging, and improved following immunotherapy. Gephyrin‐IgG is associated with a treatable autoimmune neurological disease, sometimes paraneoplastic. ANN NEUROL 2026