In 6 patients with Parkinson's disease (PD) and 6 age-matched controls, transcranial magnetic stimulation was applied at 56 regions over the motor cortex and premotor cortex of each hemisphere, with the first dorsal interosseous (FDI) muscle of both hands activated at 15% maximum voluntary contraction during stimulation. For each site, motor evoked potential (MEP) landmarks were recovered, including MEP amplitude, MEP onset latency, and silent period duration. Scaled MEP amplitudes were used to construct individual cortical maps of the FDI muscles. The maps revealed an anterior displacement of the muscle representation in PD patients. This anterior shift over motor cortical areas may reflect increased contributions of corticocortical connections between motor cortex and premotor cortical areas, possibly enhanced by the visual feedback aspect of the task. These alterations may reflect adaptations to the impairments in striatocortical circuits in PD. © 2003 Movement Disorder Society.

Item Type:	Refereed Article
Research Division:	Medical and Health Sciences
Research Group:	Neurosciences
Research Field:	Neurology and Neuromuscular Diseases
Objective Division:	Health
Objective Group:	Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:	Nervous System and Disorders
UTAS Author:	Kagerer, FA (Dr Florian Kagerer)
UTAS Author:	Summers, JJ (Professor Jeffery Summers)
UTAS Author:	Taylor, B (Professor Bruce Taylor)
ID Code:	27772
Year Published:	2003
Web of Science® Times Cited:	10
Deposited By:	Medicine
Deposited On:	2003-08-01
Last Modified:	2011-08-03
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