Flexible brain dynamics underpins complex behaviours as observed in Parkinson’s disease

Abstract

Rapid reconfigurations of brain activity support efficient neuronal communication and flexible behaviour. Suboptimal brain dynamics is associated to impaired adaptability, possibly leading to functional deficiencies. We hypothesize that impaired flexibility in brain activity can lead to motor and cognitive symptoms of Parkinson’s disease (PD). To test this hypothesis, we studied the ‘functional repertoire’—the number of distinct configurations of neural activity—using source-reconstructed magnetoencephalography in PD patients and controls. We found stereotyped brain dynamics and reduced flexibility in PD. The intensity of this reduction was proportional to symptoms severity, which can be explained by beta-band hyper-synchronization. Moreover, the basal ganglia were prominently involved in the abnormal patterns of brain activity. Our findings support the hypotheses that: symptoms in PD relate to impaired brain flexibility, this impairment preferentially involves the basal ganglia, and beta-band hypersynchronization is associated with reduced brain flexibility. These findings highlight the importance of extensive functional repertoires for correct behaviour.

Dysfunctional Brain Dynamics of Parkinson's Disease and the Effect of Acute Deep Brain Stimulation

“…Furthermore, in agreement with previous studies (Kim et al, 2017 ; Schumacher et al, 2019 ; Sorrentino et al, 2021 ), we also found that the reduced brain dynamic changes were significantly associated with clinical symptoms, indicating that longer mean duration correlated with a more severe movement disorder. In addition, we found the occurrences per second of microstates were negatively correlated with neural function, in agreement with former results.…”

“…Schumacher et al (2019) examined the brain dynamic changes of Lewy body dementia (including PD dementia) using the EEG microstate analysis and found obvious decreases compared with controls. Coincidentally, Kim et al (2017) (Sorrentino et al, 2021). In our results, the longer mean duration of a microstate is parallel to the longer mean dwell time and fewer occurrences in each microstate, which means reduced flexibility of the brain.…”

“…PD is a disabling neurodegenerative disease characterized by reduced ability to move and slowing of cognitive processes. Such degenerative changes in PD may derive from a decline in the flexibility of the brain (Sorrentino et al, 2021 ). In our results, the longer mean duration of a microstate is parallel to the longer mean dwell time and fewer occurrences in each microstate, which means reduced flexibility of the brain.…”

The structural connectome constrains fast brain dynamics

“…MEG pre-processing and source reconstruction were performed as in (22). The MEG system was equipped with magnetometers, and was developed by the National Research Council of Italy at the Institute of Applied Sciences and Intelligent Systems (ISASI).…”

“…2.5 and 3.5) were tested. An avalanche was defined as starting when any region is above threshold, and finishing when no region is active, as in (22). Avalanches shorter than 10 time bins (~30 msec) were excluded.…”