Recently, the rivastigmine patch demonstrated efficacy comparable to the highest doses of rivastigmine capsules, with markedly improved tolerability profile. The investigators hypothesized that rivastigmine patch will provide benefits to AD patients with white matter changes compared to those without any white matter changes. Possible explanation about favorable benefits for AD with white matter changes is that rivastigmine may act on both Alzheimer's and vascular pathologies contributing to dementia, providing additive treatment effects in patients suffering from both conditions concurrently. To our Knowledge, there was no study or clinical trial to compare the changes of cognitive function, ADL, BPSD and caregiver burden in two groups of patient with Alzheimer's disease associated with or without white matter changes after rivastigmine transdermal patch therapy.