[Aging of brain and the maintenance of the function].

Some diseases develop dementia, but they may be dementia-like-situation, such as depression and drugs induced one. There are many causes as an etiology of dementia. Among them a lots of diseases are treatable dementia, like chronic subdural hematoma, normal pressure hydrocephalus, brain abscess, syphilis, herpetic encephalitis, Wilson's disease, hypothyroidism, parathyroid disease, vitamin B12 deficiency, pellagra etc. In examination of patients with dementia, exact history taking, physical examination and laboratory examination should be done carefully. In the patients with Alzheimer's dementia and cerebrovascular disease's dementia, as many risk factors are known, we must try to treat and exclude each risk factor and protect the dementia. Inactivity of physical and mental function is reported to induce the dementia, so activation of them could prevent the development and the progression of dementia. In future the methods of the prevention of apoptosis and cell death would be found in order to prevent the dementia. Free radical scavenger, nerve trophic factor, cytokine, antagonist of glutamate etc. will have the possibility to become the medicine for the dementia. The nerve transplantation, nerve transmitter, nerve peptide etc. might serve as the allopathic treatment for the dementia.