The goal of this clinical trial is to learn if ultrasound-guided stellate ganglion block (SGB), added to standard drug treatment, can improve thinking and memory in people with Alzheimer's disease. It will also learn about the safety of SGB.

The main questions this study aims to answer are:

Do people who receive SGB plus standard drug treatment have better global cognition, measured by the Mini-Mental State Examination (MMSE), 1 month after finishing the treatment course compared with people who receive standard drug treatment alone? How do anxiety, depression, quality of life, and ability to live independently change over 1 month, 3 months, and 6 months after treatment? What medical problems, if any, occur during or after SGB?

Researchers will compare two groups:

SGB plus standard drug treatment Standard drug treatment alone

Participants will:

Be randomly assigned to one of the two groups Receive the assigned treatment Complete study visits and assessments at baseline and at 1 month, 3 months, and 6 months after finishing the treatment course

This is a randomized, parallel-group clinical trial in people with Alzheimer's disease. Participants are assigned to receive either ultrasound-guided stellate ganglion block (SGB) in addition to standard drug treatment or standard drug treatment alone. SGB is a procedure performed under ultrasound guidance in the neck region to temporarily block the stellate ganglion, which may influence autonomic nervous system activity.

The primary outcome is global cognition measured by the Mini-Mental State Examination (MMSE). The prespecified primary endpoint is 1 month after completion of the treatment course to capture a relatively stable post-treatment effect. Secondary outcomes include anxiety symptoms measured by the Zung Self-Rating Anxiety Scale (SAS), depressive symptoms measured by the Zung Self-Rating Depression Scale (SDS), quality of life measured by the Alzheimer's Disease Quality of Life scale (QoL-AD), and independent living ability measured by the Lawton-Brody Instrumental Activities of Daily Living scale (IADL). Outcomes are assessed at baseline and at 1 month, 3 months, and 6 months after completion of the treatment course.

Safety is evaluated by monitoring and recording adverse events related to the procedure and study participation throughout the treatment period and follow-up.

Inclusion Criteria:

1. Age 55 to 85 years.
2. Diagnosis of Alzheimer's disease (AD) based on the 2011 NIA-AA criteria.
3. Mild to moderate cognitive impairment assessed by the Mini-Mental State Examination (MMSE).
4. Ability to understand study procedures and provide written informed consent by the participant or a legally authorized representative.
5. Ability to complete scheduled follow-up assessments.

Exclusion Criteria:

1. Known allergy to lidocaine, coagulation disorders, or other contraindications to stellate ganglion block (SGB).
2. Severe cardiac, hepatic, or renal disease that could compromise safety.
3. Cranial surgery or major head trauma within the past 6 months.
4. Participation in other interventional trials that could affect study outcomes.
5. Cognitive impairment primarily due to other neurodegenerative diseases or psychiatric disorders.

Individual participant data (IPD) will not be shared because the dataset contains sensitive clinical information, and public or external sharing is not permitted under the informed consent, ethics approval requirements, and institutional policies. To protect participant privacy and confidentiality, only aggregated, de-identified results will be reported.

Outcome assessors were blinded to group assignment.