56. Neurophysiological features of motor cortex excitability and plasticity in subcortical ischemic vascular dementia: A TMS mapping study.

Motor cortex hyperexcitability as a possible reflection of restorative plasticity is a well defined neurophysiological feature of Alzheimer’s disease (AD), probably related to its severity and progression. Vascular Dementia is the second most common type of dementia and it is mainly represented by an homogeneous subtype that is the Subcortical Ischemic Vascular Dementia (SIVD). To date, only few studies investigating motor cortex functionality in SIVD have been published and in none of them the TMS motor cortex mapping technique was used. The aim of this investigation was then test and better characterize neurophysiological features of motor cortex excitability and plasticity in SIVD by means of a TMS mapping study. Results showed that even though in SIVD the motor cortex was found to be hyperexcitable and functionally rearranged however the neurophysiological profile identified did not lead to a clear distinction between vascular and neurodegenerative dementia. On the other hand, in the examined population a significant direct correlation was seen between parameters associated to cortical excitability and those related to cortical plasticity, supporting the idea that cortical hyperexcitability can promote cortical plasticity and shading light on possible rehabilitative strategies. [ABSTRACT FROM AUTHOR]