A patient’s brain atrophy is not necessarily Alzheimer’s disease. Brain atrophy may cause memory function decline and cognitive dysfunction in severe cases, and is a neurodegenerative disease. The chance of brain atrophy increases significantly with age and is caused by the degeneration of brain cells. A deepening of the sulci and narrowing of the gyrus may be seen on brain MRI or brain CT. Dementia can be seen for a variety of reasons, with Alzheimer’s disease being the most common disease, but also dementia with Lewy bodies, multi-system atrophy, and more. Pre-dementia can also appear memory function decline, mainly for near memory decline obviously, with the aggravation of the disease, may appear cognitive dysfunction, can apply some drugs to improve brain metabolism, can also apply donepezil, may improve the symptoms.