EEG Microstate Characteristics of Emotional Activation in Tremor Variability in Wilson’s Disease Patients

Objective To investigate the neural mechanisms underlying emotion-induced tremor variability in Wilson’s disease (WD) patients via electroencephalography (EEG) microstate analysis. Methods Forty-five tremor-dominant WD patients and 20 healthy controls underwent assessments with the Body Image Disturbance Questionnaire (BIDQ), Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS), Self-Assessment Manikin (SAM) and Facial Expression Recognition (FER) tasks. Tremor kinematics were quantified via Kinovea, and EEG microstates were analyzed during emotion induction. Structural magnetic resonance imaging (MRI) was used to evaluate brain atrophy patterns. Results WD patients exhibited greater social avoidance ( Z = -5.721, p < 0.05), prolonged FER reaction times (1.78 s vs. 1.05 s, p < 0.001), and increased negative face selections (6 vs. 5, p = 0.036). Negative emotional states amplified tremor amplitude (3.79 px vs. 3.16 px , p = 0.012). EEG microstates revealed elevated microstate C (salience network) frequency (4.74/min vs. 3.41/min, p < 0.001) and coverage (16% vs. 13%, p < 0.001) during negative emotion, which was correlated with tremor severity ( ρ = 0.319, p = 0.039). Regression identified lentiform nucleus damage ( β =0.361), cerebellar atrophy ( β = 0.300) and frontal atrophy ( β = −0.386) as predictors of emotional arousal ( R² = 0.277, p = 0.042). Conclusion Emotion–tremor coupling in WD involves dysregulated salience networks and cerebellar–frontal–lentiform circuits, with EEG microstate C as a potential marker for targeted interventions.