Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of the central nervous system. It remains unclear whether pathological changes in ALS can lead to abnormalities in neural dynamics and how these abnormalities relate to key clinical characteristics of ALS. Nonlinear neural dynamics analyses of electroencephalography (EEG) sensorimotor channels were conducted using recurrence quantification analysis (RQA), permutation Lempel-Ziv complexity (PLZC), shannon entropy (ShannonE) and permutation entropy (PermEn). Whole-brain spatiotemporal topological dynamics were assessed using microstate analysis. The study shows that the nonlinear neural dynamics across all frequency bands in the sensorimotor channels of ALS patients are impaired (reduction in Shannon Entropy of Diagonal Line Length Distribution [ENTR]). Frequency-specific nonlinear neural dynamics indicate increased nonlinear neural dynamics in high-frequency bands (with increases in PLZC in beta2 (20-25 Hz)). Nonlinear neural dynamics in low-frequency bands decreases (with decreases in ShannonE in theta (4-7 Hz)) and is negatively correlated with disease duration. ENTR across all frequency bands and ShannonE in the theta band of the sensorimotor channels are potential protective factors for ALS. Furthermore, sensorimotor channel analysis shows a close relationship with whole-brain spatiotemporal topological neural dynamics. Duration A is positively correlated with RR, DET and ENTR, while Occurrence B is negatively correlated with it. The study demonstrates widespread abnormalities in the neural dynamics of ALS, which are closely related to clinical characteristics of ALS. There is also a close relationship between the neural dynamics of sensorimotor channels and whole-brain spatiotemporal topological dynamics in ALS patients.

Objective: This study aimed to investigate the EEG microstate characteristics in patients with persistent Omicronrelated Psychiatric Symptoms (ORPS) as well as their correlations with the severity of ORPS. Methods: This study included 31 patients with ORPS, and they were divided into remission group (n=19) and non-remission group (n=12) according to the decrease of Brief Psychiatric Rating Scale (BPRS) at discharge. Multivariate logistic models were applied to analyze the risk features associated with non-remission of ORPS at discharge, and the Spearman rank correlation was adopted to analyze the correlation between the occurrence of microstate class B and BPRS score at admission. Results: The analysis revealed that an increased occurrence of EEG microstate class B was significantly associated with a higher likelihood of non-remission of ORPS at discharge (p < 0.05). Furthermore, a moderate positive correlation was observed between the occurrence of microstate class B and BPRS scores at admission (r = 0.390, p = 0.030), indicating that patients with more frequent microstate class B tended to exhibit more severe psychiatric symptoms at onset. Conclusions: The findings suggest that an increased occurrence of EEG microstate class B is an independent risk factor for non-remission of ORPS at discharge. Additionally, the positive correlation between microstate class B and BPRS scores underscores the potential of microstate class B as a biomarker for the severity of psychiatric symptoms in ORPS patients. Significance: Identifying the increased occurrence of microstate class B at admission could serve as a novel marker for early assessment of ORPS severity and prognostic evaluation.