Due to increase of population of elderly patients, dramatic increase of patients with dementia is becoming a serious social problem in Japan. At the moment it is being estimated that more than one million patients suffer from dementia in Japan. Among the patients with dementia, Alzheimer's disease and cerebrovascular dementia are the leading cause for dementia. In clinical practice, it is important to make a correct diagnosis for dementia. Special attention should be made not to misdiagnose “treatable dementia”.
On the basis of a genetic view point, Alzheimer's disease can be classified into familial Alzheimer's disease as a single gene disease, and sporadic Alzheimer's disease as a polygenic disease. The causative genes for familial Alzheimer's disease have been found to be amyloidprecursor protein gene on chromosome 21, presenilin I on chromosome 14 and presenilin II on chromosome 1. As a genetic risk factor for sporadic Alzheimer's disease as well as late-onset Alzheimer's disease, an isoform of apolipoprotein E (ApoE4) has been found to play an important role for the pathogenesis of Alzheimer's disease. Given the genes which are involved in the pathogenesis of Alzheimer's disease, the elucidation of the mechanisms of Alzheimer's disease and the development of strategies for the treatment of Alzheimer's disease should become a reality in the near future.

Clinical case studies and reporting are important to the discovery of new disorders and the advancement of medical sciences. Both clinicians and basic scientists play equally important roles leading to treatment discoveries for both cures and symptoms. In the field of movement disorders, exceptional observation of patients from clinicians is imperative, not just for phenomenology but also for the variable occurrences of these disorders, along with other signs and symptoms, throughout the day and the disease course. The Movement Disorders in Asia Task Force (TF) was formed to help enhance and promote collaboration and research on movement disorders within the region. As a start, the TF has reviewed the original studies of the movement disorders that were preliminarily described in the region. These include nine disorders that were first described in Asia: Segawa disease, PARK-Parkin, X-linked dystonia-parkinsonism, dentatorubral-pallidoluysian atrophy, Woodhouse-Sakati syndrome, benign adult familial myoclonic epilepsy, Kufor-Rakeb disease, tremulous dystonia associated with mutation of the calmodulin-binding transcription activator 2 gene, and paroxysmal kinesigenic dyskinesia. We hope that the information provided will honor the original researchers and help us learn and understand how earlier neurologists and basic scientists together discovered new disorders and made advances in the field, which impact us all to this day.