Motor cortex hyperexcitability in subcortical ischemic vascular dementia

To study whether in subcortical ischemic vascular dementia (SIVD) the changes of motor cortexexcitability are due to the dementing process or to the cerebrovascular lesions, we examined 20 SIVDpatients, 20 patients with subcortical ischemic disease without dementia (SIDWD) and 20 controlsubjects who underwent transcranial magnetic stimulation (TMS). Motor threshold (MT), amplitudes ofmotor evoked potentials (MEPs) and silent period (SP) were considered. MT in SIVD patients(32.7 2.6%) was significantly lower (p < 0.001) than in SIDWD patients (47.9 3.4%) and in controls(49.1 4.2%). MEP amplitude was larger in SIVD patients (6.8 1.7 mV) than in the other groups(5.7 1.9 mV and 5.2 1.8 mV, p < 0.02). Motor cortex excitability is enhanced in SIVD. Our data, takentogether with previous results in Alzheimer disease (AD), indicate that motor cortex hyperexcitability is acommon finding in different dementing illnesses.