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

Inclusion Criteria:

• Meeting the diagnostic criteria for dementia formulated by the National Institute onAging-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 subjectand 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, ordrug-induced psychosis.

• Severe internal diseases, currently usingrespiratory/cardiovascular/anticonvulsant/psychotropic drugs, or clinicallysignificant gastrointestinal, renal, hepatic, respiratory, infectious, endocrine, orcardiovascular 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, frontotemporaldementia, or infectious dementia;

• Any other condition deemed by the investigator as unsuitable for the study