Dementia Progressive exacerbation, myoclonus, ataxia, visual impairment, pyramidal and extrapyramidal signs. Electroencephalogram (EEG) periodic high amplitude spike-slow waves (typical triphasic waves). MRI white matter degeneration. Biopsy confirms the diagnosis. Creutzfeldt-Jabob disease is characterized by a history of stroke and cognitive deficits occurring within 3 months of stroke, either suddenly or in a stepwise slow progression. Neurologic focal signs. Imaging shows multiple infarct foci. Vascular dementia Progressive mental retardation, memory, cognitive impairment, and psychiatric symptoms. Extrapyramidal symptoms appear late. Imaging shows marked frontal and parietal atrophy. Alzheimer’s disease (AD) Early manifestations of personality changes, poor self-awareness and social behavior, amnesia, spatial orientation and cognitive impairment appear later. Imaging shows frontal and temporal lobe atrophy. Pathology shows neocortical or hippocampal neuronal cytoplasm with silver-stained inclusions of Pick’s vesicles. Pick’s disease Clinical manifestations are mainly progressive dementia, Parkinson’s syndrome and psychiatric symptoms highlighted by visual hallucinations Pathology shows Lewy inclusion bodies. Dementia occurs in early or old age, lasts for weeks or months, and is characterized by at least one of the following: 1. often accompanied by hallucinations or auditory hallucinations. 2. mild extrapyramidal features or sensitivity syndrome to neuroleptic drugs. 3. recurrent unexplained falls or transient blurring or loss of consciousness. Rule out other disorders, including stroke. Lewy inclusion body dementia Most common in the elderly, characterized by symptoms of both cortical and basal ganglia function, may be accompanied by Parkinson’s syndrome, symptoms are often very asymmetric, and the use of compound dopamine preparations is effective. The diagnosis is confirmed at autopsy. Corticobasal ganglia degeneration with dementia and Parkinson’s manifestations, resting tremor, muscle tone, bradykinesia, postural gait abnormalities, and levodopa treatment. Parkinson’s disease dementia Parkinson’s symptoms, visual hallucinations, fluctuating cognitive deficits, with memory and alertness abnormalities. Motor symptoms usually appear more than 1 year after the mental disorder, fall easily, and are sensitive to psychotropic drugs. Dementia with Lewy bodies (DLB) is easily confused with early mild cognitive impairment, the main difference being that amnesia improves with reminders. Neuropsychological scales show that his memory is normal both near and far, and he has no personality or psychiatric disorders. Amnesia in the elderly usually occurs after brain diseases, head trauma, or idiopathic, with the typical triad of dementia, gait disturbance, and dysuria. Dementia is mainly subcortical, with mild cognitive decline and reduced spontaneous activity. In the later stages, there is slowed emotional response and memory impairment. Anxiety, aggressive behavior and delusions may occur. Early incontinence, urinary frequency. Later, incomplete urination and dribbling after urination. Imaging shows enlarged ventricles. Cerebrospinal fluid pressure is normal.