Related Experiment Video
Updated: May 29, 2026
Standardized Induction and Assessment of Long-term Potentiation-like Cortical Plasticity Using Transcranial Magnetic Stimulation
Published on: November 7, 2025
Effects of theta burst stimulation on motor cortex excitability in Parkinson's disease
Orit Zamir1, Carolyn Gunraj, Zhen Ni
1Division of Neurology, Department of Medicine, University of Toronto and Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada.
Objective:
Long-term potentiation (LTP)-like plasticity induced by paired associative stimulation (PAS) is impaired in Parkinson's disease (PD). Intermittent theta burst stimulation (iTBS) is another rTMS protocol that produces LTP-like effects and increases cortical excitability but its effects are independent of afferent input. The aim of the present study was to examine the effects of iTBS on cortical excitability in PD.
Methods:
iTBS was applied to the motor cortex in 10 healthy subjects and 12 PD patients ON and OFF dopaminergic medications. Motor evoked potential (MEP) before and for 60 min after iTBS were used to examine the changes in cortical excitability induced by iTBS. Paired-pulse TMS was used to test whether intracortical circuits, including short interval intracortical inhibition, intracortical facilitation, short and long latency afferent inhibition, were modulated by iTBS.
Results:
After iTBS, the control, PD ON and OFF groups had similar increases in MEP amplitude compared to baseline over the course of 60 min. Changes in intracortical circuits induced by iTBS were also similar for the different groups.
Conclusions:
iTBS produced similar effects on cortical excitability for PD patients and controls.
Significance:
Spike-timing dependent heterosynaptic LTP-like plasticity induced by PAS may be more impaired in PD than frequency dependent homosynaptic LTP-like plasticity induced by iTBS.
More Related Videos
12:13Assessing Primary Motor Cortex Excitability and Excitability Modulation by Pairing Transcranial Magnetic Stimulation with Electromyography
Published on: October 7, 2025
06:42Continuous Theta Burst Stimulation of the Posterior Medial Frontal Cortex to Experimentally Reduce Ideological Threat Responses
Published on: September 28, 2018