1. Cognitive function symptoms 1. Memory impairment: It is often a prominent symptom in the early stage of dementia, and initially mainly involves recent memory, difficulty in memory preservation and learning new knowledge. The symptoms include forgetfulness, forgetting things that have just been used, losing everyday objects, not being able to remember the names of people or places that have recently come into contact with them, saying the same things or asking the same questions over and over again. Often forget important appointments. As the disease progresses, distant memory is also impaired, and one cannot recall one’s work experience and life experience. In severe cases, one cannot even recall accurately how many people are in the family, one’s name, age and occupation. In order to compensate for the memory deficit, some patients fill in the memory gaps with fiction or misrepresentation. 2. Visuospatial dysfunction: It is also one of the early symptoms of dementia, manifested as getting lost in a familiar environment, not being able to find the door of one’s home, or even going to the wrong room in one’s own home or not being able to find the toilet. In simple drawing experiments, patients cannot accurately copy cube diagrams and often cannot copy simple figures. 3, abstract thinking disorder: cognitive functions such as understanding, reasoning, judgment, generalization and calculation are impaired in patients with dementia. First of all, it is difficult to calculate and cannot perform complex arithmetic. Patients gradually appear to be slow and slow in thinking, their abstract thinking ability decreases, they cannot distinguish the similarities and differences of things, and they cannot make analysis and generalization. They can’t read novels and movies, can’t understand other people’s conversation, can’t complete or be competent in their familiar work and technology, and finally lose their ability to live completely. 4, language disorder: language disorder is a more sensitive indicator of cortical dysfunction, the specific pattern of language disorder helps the diagnosis of this disease, in dementia patients, the earliest language abnormalities are spontaneous speech hollow, difficulty in finding words, improper use of words, redundant, not to be understood, can not list the names of similar items, followed by naming can not, can also appear sensory aphasia, can not carry on a conversation, can have imitation language, stereotyped The patient can only make ah-energy sounds, or be silent. 5. Aphasia: The most common form of aphasia in dementia patients is the inability to recognize faces, the inability to recognize relatives and friends, and even the loss of the ability to recognize oneself. 6. Disuse: The disuse of dementia is manifested by the inability to make complex movements correctly and continuously, such as brushing teeth, putting on clothes in the wrong order of inside and outside, front and back, left and right, and not being able to use chopsticks and spoons to eat, but often grabbing food with hands. 7. Personality changes: coldness to people, selfishness, reduced interest in the surrounding environment, lack of enthusiasm for people, instinctive activity, public nudity, and even abnormal sexual activity. Decline in living ability Patients with dementia have a significant decline in daily living ability due to the decline in memory, judgment, thinking and other abilities, and gradually need to be taken care of by others, and their dependence on others is increasing, and in severe cases, they are completely unable to take care of themselves. Mental behavior abnormalities include hallucinations, delusions, mistaken identity, depression, mania-like, agitation, aimless wandering, wandering, physical and verbal aggression, shouting, open defecation and sleep disorders, etc.