This research aims to observe the efficacy and safety of surgery compared with traditional medical treatment for moderate to severe dementia in Alzheimer's disease. This is a prospective multicenter RCT clinical research, involving a total of 3 research centers.Patients diagnosed with Alzheimer's disease accompanied by moderate to severe cognitive dysfunction in these three hospitals from January 2025 to January 2027 were included. This research is expected to recruit a total of 186 patients with moderate to severe Alzheimer's disease.93patients received conventional medical treatment, Deep cervical lymphatic-venous anastomosis was performed in 93 patients.Comprehensively evaluate the efficacy and safety of the patients within 48 weeks after treatment.

Alzheimer's disease is a degenerative disorder of the central nervous system characterized by progressive cognitive dysfunction and behavioral impairment. At present, the treatment strategies for Alzheimer's disease include drug therapy, non-drug therapy and some emerging treatment methods. However, clinical evidence has confirmed that the effects of these treatment measures are limited. In recent years, Some neurosurgeons in China have begun to attempt to improve the disease progression of severe Alzheimer's disease through the innovative microscopic surgical method of deep jugular lymphovenous anastomosis. The therapeutic principle is Lymph node reconstruction is carried out using microsurgical techniques to improve the lymphatic circulation and return of the brain, accelerate the excretion of pathological proteins, the metabolic products of the brain, thereby delaying the degenerative changes of the brain and the progression of Alzheimer's disease. To verify the above assumption, this study will collaborate with a total of three institutions, namely Ruijin Hospital, Luwan Branch and Wuxi Branch. It is estimated that 186 patients with moderate to severe dementia of Alzheimer's disease will be included. They were randomly divided into the surgical treatment group (93 cases) and the traditional medical treatment group (93 cases). Cognitive function assessment, PETMR imaging examination, cerebrospinal fluid/blood testing and quality-adjusted life years were analyzed respectively at the 1st week, 4th week, 12th week, 24th week and 48th week after conservative treatment or surgery. To observe the efficacy and safety of surgery compared with traditional medical treatment for moderate to severe dementia in Alzheimer's disease.

Inclusion Criteria:

1. The patient was clinically diagnosed with Alzheimer's disease and had a moderate to severe cognitive function score.
2. Age: 30-80 years old.
3. Gender is not limited.
4. The patient or their family members authorize their willingness to participate in this clinical trial and sign the informed consent form.
5. no contraindications for surgery.

Exclusion Criteria:

1. A history of radiotherapy or surgery for the head and neck.
2. Patients or their families with poor compliance who cannot strictly follow the rules.
3. Patients who cannot tolerate surgery.
4. Patients with other diseases that affect cognitive function.
5. Patients who cannot tolerate donepezil drug treatment.