Dubey, Divyanshu

Background Patients with anti-leucine-rich glioma-inactivated 1 (anti-LGI1) autoimmune encephalitis (AIE) frequently present with faciobrachial dystonic seizures (FBDS), which are often under-detected due to their subtle motor features and lack of consistent EEG correlates. Conventional in-hospital monitoring and patient-reported seizure diaries are limited, particularly during nocturnal periods. In this pilot feasibility study, we evaluated the use of a wearable device (Empatica E4) to objectively monitor FBDS-related motor and autonomic activity in seven patients with anti-LGI1 AIE and four control subjects. Methods Wearable recordings included accelerometry (ACC), electrodermal activity (EDA), photoplethysmography (PPG) and skin temperature. A support vector machine-based algorithm was developed to identify disorder-related events using ACC and EDA features. Analyses were restricted to sleep periods to minimise confounding from voluntary movements. Results Pretreatment recordings from two patients (P1 and P2) showed significantly elevated motor event frequency, ACC magnitude and EDA activity compared to controls. Post-treatment recordings demonstrated marked reductions in these metrics, consistent with patient-reported clinical improvement. Other patients showed variable results depending on treatment timing and signal quality. Conclusion Our pilot study demonstrates the feasibility of using wearable technology for objective, real-world monitoring and assessment of patient status in anti-LGI1 AIE. Nocturnal monitoring offers a low-noise baseline for detecting seizure-related activity and may support earlier diagnosis, more accurate evaluation of treatment response and reduced reliance on resource-intensive inpatient evaluations. Future studies should expand monitoring to daytime periods and validate findings against conventional modalities such as video-EEG and electromyography polygraphy.

Abstract High‐titer glutamic acid decarboxylase 65 (GAD65) antibodies (>20 nmol/L) are linked to chronic focal epilepsy, usually of temporal regional onset. Identification of these antibodies has treatment and prognostic implications. We compared patients with drug‐resistant epilepsy and high‐titer GAD65 antibodies to an age‐ and sex‐matched control group with drug‐resistant GAD65 antibody–negative temporal lobe epilepsy. From 1432 patients presented at a single‐center surgical epilepsy conference (2007–2024), we identified 15 patients (1% from surgical epilepsy conference: 13 female, 86.7%) with high‐titer serum GAD65 antibodies (median serum titer = 960 nmol/L; range 34–4678). The median age at epilepsy onset was 25 years (range 4–44). All had temporal regional‐onset epilepsy; 53% had bitemporal seizures. Three patients had limbic encephalitis, and three developed mesial temporal sclerosis. Those with GAD65 antibody–associated epilepsy were more likely to have depression and/or anxiety and less likely to undergo resection after evaluation than those in the control group. Although seizure types, electroencephalography (EEG), imaging, and autoimmune history were not statistically significantly different from the control group, we found that musicogenic seizures, limbic encephalitis, and type 1 diabetes occurred only in GAD65‐positive patients. These features, when present, may suggest an autoimmune etiology and warrant antibody testing. Identifying patients with GAD65 antibody–associated epilepsy is important due to its drug resistance, lower rate of satisfactory surgical outcomes, and potential responsiveness to immunotherapy. Further research is needed to define the optimal treatment and distinguish this subgroup from other causes of drug‐resistant epilepsy.