This situation primarily arises from brain atrophy causing Alzheimer's disease, which is a very common neurodegenerative disorder. In the middle and late stages, patients may exhibit significant personality changes, becoming irritable, easily angered, and paranoid, often engaging in behaviors such as hitting or cursing others. They may also experience hallucinations, such as vivid visual and auditory hallucinations. The disease is mainly due to the degeneration and death of neurons in the temporal lobe and hippocampus, leading to the atrophy of the cerebral cortex. This causes the release of some of the patient's primitive instincts, leading to a series of clinical manifestations, which can be symptomatically managed.