A sagittal gradient of pathological and compensatory effects of neurophysiological slowing in Parkinson’s disease

Abstract

Using magnetoencephalographic imaging and extensive clinical and neuropsychological assessments, we show that patients with Parkinson's disease (PD; N = 79) exhibit a slowing of neurophysiological activity relative to healthy adults (N = 65), which relates to motor and cognitive abilities. Importantly, the association between neurophysiological slowing and PD clinical features varies systematically across the cortex along a sagittal gradient: cortical slowing is associated with worse impairment in dorsal-posterior cortices, and this association is reversed in ventral-anterior cortical regions. This pathological-to-compensatory anatomical gradient is sensitive to differences in patients' individual clinical profiles, and co-localizes with normative atlases of neurotransmitter receptor/transporter density. Long-range functional connectivity between posterior regions and parietal and frontal cortices is also significantly shifted towards lower frequencies in PD, demonstrating a novel network-level slowing effect. Taken together, these findings demonstrate the multifaceted nature of neurophysiological slowing in patients with PD, with anatomically-dependent clinical relevance to motor and cognitive symptoms.

Cortex-wide topography of 1/f-exponent in Parkinson’s disease

“…19.524792 doi: bioRxiv preprint power in sensorimotor regions of PD patients. In a more recent study, Wiesman et al 12 estimated the aperiodic activity on four different frequency bands showing a neurophysiological slowingdecrease through frequency of the λ deviation from HC. Finally, Wang et al 13 studied low-spatial resolution EEG from PD-ON and OFF medication showing that there is a significant increase of the offset and exponent power law parameters from OFF to ON medication in some of the sensors.…”

Spectral slowing in chronic stroke reflects abnormalities in both periodic and aperiodic neural dynamics

“…With this more complete characterization of electrophysiological abnormalities in terms of underlying dynamics, we are better situated to investigate the potential physiological causes and clinical consequences of spectral slowing in stroke. Furthermore, a similar approach can further our understanding of other patient groups known to show spectral slowing, such as those with dementia ( Moretti, 2004 , Neto et al, 2015 ), Parkinson’s disease ( Wiesman et al, 2022 ), brain tumor ( Bosma et al, 2008 ), and multiple sclerosis ( Kim et al, 2019 ).…”

Theta oscillations and minor hallucinations in Parkinson’s disease reveal decrease in frontal lobe functions and later cognitive decline

“…with vs. without dementia) (e.g. Hassan et al, 2017; Morita et al, 2011; Soikkeli et al, 1991; Stoffers et al, 2007; Wiesman et al, 2022). Accordingly, it is not known whether these previous oscillatory differences are only present in patients with cognitive deficits due to advanced PD, whether they depend on differences in disease duration or medication, or other clinical variables likely differing between previously tested groups.…”