Abnormal intrinsic neural timescale and reduced grey matter volume in Parkinson’s disease

Abstract

Background: The intrinsic neural timescale in a local brain area has been specialized, and the sensory and prefrontal areas have shorter and longer timescales, respectively. Parkinson's disease (PD) is a progressive neurological disorder that also exhibits with abnormal neural activity in sensorimotor, visual, and cognitive-related areas. However, it was unclear whether PD patients exhibited abnormal intrinsic timescales and whether PD patients exhibited different temporal feature at different stages. Methods: Here, we estimated the intrinsic timescales using the magnitude of the autocorrelation of intrinsic neural signals by resting state functional magnetic resonance imaging data in 74 PD patients, including 44 patients in the early stage (PD-ES) and 30 patients in the late stage (PD-LS), and 73 healthy controls (HC). Results: We identified that the PD group had shorter timescales in bilateral lingual and calcarine gyri, bilateral postcentral and precentral gyri, and the right middle cingulum gyrus than the HC group, which correlated with the age, but not in the HC group. Moreover, shorter timescales in the PD group also correlated with the symptom severity and reduced grey matter volume (GMV). Longer timescale in the right middle frontal gyrus was also found in the PD group than that in the HC group. Increasingly, compared to the HC group, the PD-ES group had longer timescales in the anterior cortical regions, including the left superior and inferior frontal gyri, and the right middle frontal gyrus, whereas the PD-LS group had shorter timescales in the posterior cortical regions, including bilateral calcarine and lingual gyri, which accompanied with more serious cognitive impairments and reduced GMV. Conclusions: Our findings suggest that PD patients exhibit abnormal intrinsic timescales in visual, sensorimotor, and cognitive systems, which might provide new insights for the neural substrate of PD. Distinct patterns of intrinsic timescales in cerebral cortex between the PD-LS and PD-ES groups indicate that intrinsic timescale might be a new neuroimaging biomarker across disease stage in PD.