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. 2022 Apr;37(4):734-744.
doi: 10.1002/mds.28914. Epub 2022 Jan 9.

Motor Cortical Network Excitability in Parkinson's Disease

Giorgio Leodori  1   2 , Maria Ilenia De Bartolo  1 , Andrea Guerra  1 , Andrea Fabbrini  2 , Lorenzo Rocchi  3   4 , Anna Latorre  3 , Giulia Paparella  1 , Daniele Belvisi  1   2 , Antonella Conte  1   2 , Kailash P Bhatia  3 , John C Rothwell  3 , Alfredo Berardelli  1   2
Affiliations

Motor Cortical Network Excitability in Parkinson's Disease

Giorgio Leodori et al. Mov Disord. 2022 Apr.

Abstract

Background: Motor impairment in Parkinson's disease (PD) reflects changes in the basal ganglia-thalamocortical circuit converging on the primary motor cortex (M1) and supplementary motor area (SMA). Previous studies assessed M1 excitability in PD using transcranial magnetic stimulation (TMS)-evoked electromyographic activity. TMS-evoked electroencephalographic activity may unveil broader motor cortical network changes in PD.

Objective: The aim was to assess motor cortical network excitability in PD.

Methods: We compared TMS-evoked cortical potentials (TEPs) from M1 and the pre-SMA between 20 PD patients tested off and on medication and 19 healthy controls (HCs) and investigated possible correlations with bradykinesia.

Results: Off PD patients compared to HCs had smaller P30 responses from the M1s contralateral (M1+) and ipsilateral (M1-) to the most bradykinetic side and increased pre-SMA N40. Dopaminergic therapy normalized the amplitude of M1+ and M1- P30 as well as pre-SMA N40. We found a positive correlation between M1+ P30 amplitude and bradykinesia in off PD patients.

Conclusions: Changes in M1 P30 and pre-SMA N40 in PD suggest that M1 excitability is reduced on both sides, whereas pre-SMA excitability is increased. The effect of dopaminergic therapy and the clinical correlation suggest that these cortical changes may reflect abnormal basal ganglia-thalamocortical activity. TMS electroencephalography provides novel insight into motor cortical network changes related to the pathophysiology of PD. © 2022 International Parkinson and Movement Disorder Society.

Keywords: Parkinson's disease; bradykinesia; motor cortex; supplementary motor area; transcranial magnetic stimulation-electroencephalography.

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References

    1. DeLong MR. Primate models of movement disorders of basal ganglia origin. Trends Neurosci 1990;13:281-285.
    1. Wichmann T. Changing views of the pathophysiology of parkinsonism. Mov Disord 2019;34:1130-1143.
    1. Underwood CF, Parr-Brownlie LC. Primary motor cortex in Parkinson's disease: functional changes and opportunities for neurostimulation. Neurobiol Dis 2021;147:105159
    1. Pasquereau B, Turner RS. Primary motor cortex of the parkinsonian monkey: differential effects on the spontaneous activity of pyramidal tract-type neurons. Cereb Cortex 2011;21:1362-1378.
    1. Pasquereau B, DeLong MR, Turner RS. Primary motor cortex of the parkinsonian monkey: altered encoding of active movement. Brain 2016;139:127-143.

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