Session Information
Date: Tuesday, June 6, 2017
Session Title: Parkinson's Disease: Pathophysiology
Session Time: 1:45pm-3:15pm
Location: Exhibit Hall C
Objective: To check whether hand dexterity in Parkinson’s disease (PD) patients is linked with motor cortex excitability and plasticity.
Background: Hand dexterity is impaired in PD patients. Primary motor cortex (M1) shows number of impairments in excitability and plasticity. There has been scarce attempts to check whether there is a link between impaired neurophysiological measures and impaired hand dexterity.
Methods: Measures of M1 excitability, short latency intracortical inhibition (SICI) and intracortical facilitation (ICF), and plasticity, relative increase in size of motor evoked potentials (MEP) elicited by transcranial magnetic stimulation (TMS) following paired associative stimulation (PAS) protocol, were collected in a group of 29 PD patients (Hoehn & Yahr stage range 1 – 4). They were correlated with results on the Perdue pegboard task (PPT), as a measure of hand dexterity, carried out with the worst affected hand, as well as with scores on standards clinical scale, motor section of the Unified Parkinson’s Disease Scale (UPDRS). Patients were tested off medication, after an overnight withdrawal.
Results: Increase in MEP size immediately after and 30 minutes after the PAS protocol did not correlate with either PPT score or UPDRS motor cores and two derived scores, lateralised UPDRS and bradykinesia score (for the worst affected side). Same was with ICF. However, there was a significant correlation between amount of SICI and PPT score (Spearman R=0.42, p=0.023) – the larger the inhibition the higher the PPT scores; SICI did not correlate with other clinical measures.
Conclusions: Hand dexterity in untreated PD patients seems to be associated with intracortical inhibition. Lack of adequate short-latency intracortical inhibition most likely interferes with fine selection of movements which is of crucial importance for hand dexterity.
To cite this abstract in AMA style:
S. Filipović, A. Kačar, S. Milanović, M. Ljubisavljević, V. Kostić. Impaired intracortical inhibition is associated with reduced hand dexterity in Parkinson’s disease patients [abstract]. Mov Disord. 2017; 32 (suppl 2). https://www.mdsabstracts.org/abstract/impaired-intracortical-inhibition-is-associated-with-reduced-hand-dexterity-in-parkinsons-disease-patients/. Accessed June 15, 2025.« Back to 2017 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/impaired-intracortical-inhibition-is-associated-with-reduced-hand-dexterity-in-parkinsons-disease-patients/