Study Safety and Efficacy of Deep Brain Stimulation (DBS) and Cervical Deep Lymphoid-venous Anastomosis (LVA) in Alzheimer's Disease

Study Safety and Efficacy of Deep Brain Stimulation (DBS) and Cervical Deep Lymphoid-venous Anastomosis (LVA) in Patients With Severe Alzheimer's Disease

To investigate the safety of deep brain stimulation (DBS) and cervical deep lymphoid-venous anastomosis (LVA) in the treatment of severe Alzheimer's disease (AD); to investigate the effectiveness of DBS and LVA in the treatment of severe AD, i.e., effects of deep brain stimulation on cognitive function, emotion and life quality in patients with severe AD.

Inclusion Criteria:

• Meeting the diagnostic criteria for dementia formulated by the National Institute on Aging-Alzheimer's Association (NIA-AA).
• Clinical Dementia Rating (CDR) score of 3 points.
• Ability to ambulate independently or with the aid of a walker/cane.
• Adequate visual and auditory capacity to cooperate with examinations and treatment.
• Voluntary participation with written informed consent provided by both the subject and their legal guardian.

Exclusion Criteria:

• Pre-existing abnormal brain structure (e.g., tumor, cerebral infarction, hydrocephalus, or intracranial hemorrhage).
• Comorbidity with other neurological disorders such as multiple sclerosis, epilepsy, or Parkinson's disease.
• Psychiatric disorders: e.g., anxiety, depression, other affective disorders, or drug-induced psychosis.
• Severe internal diseases, currently using respiratory/cardiovascular/anticonvulsant/psychotropic drugs, or clinically significant gastrointestinal, renal, hepatic, respiratory, infectious, endocrine, or cardiovascular diseases, cancer, alcoholism, or substance addiction.
• Severe auditory or visual impairment.
• Clinical comorbidities with life expectancy <2 years.
• History of cranial surgery.
• Contraindications to MRI or transcranial alternating current stimulation (tACS) (e.g., cardiac pacemaker, post-deep brain stimulation surgery).
• Eczema or sensitive skin.
• Familial Alzheimer's disease.
• Other types of dementia: e.g., vascular dementia, Lewy body dementia, frontotemporal dementia, or infectious dementia;
• Any other condition deemed by the investigator as unsuitable for the study