An Exploratory Study to Confirm Efficacy of Modified Deep Cervical Lymphovenous Anastomosis (LVA) in Alzheimer's Disease/ Parkinson's Disease

This study tests a new surgical procedure — a small operation on lymphatic vessels in the neck — to see if it can improve symptoms in people with Alzheimer's disease or Parkinson's disease by helping the brain clear waste more effectively. **You may be eligible if (Alzheimer's):** - You are between 50 and 75 years old - You have mild memory loss or early dementia caused by Alzheimer's disease - You have a positive amyloid brain scan - You are in a stable enough condition for minor surgery **You may be eligible if (Parkinson's):** - You are between 50 and 80 years old - You have been diagnosed with Parkinson's disease for 2–5 years - You are in an early to moderate stage of the disease **You may NOT be eligible if:** - You have contraindications to MRI scans, PET scans, or lumbar puncture - You have serious heart, lung, kidney, or liver disease - You have poorly controlled thyroid problems, high blood pressure, or active infections (including HIV) - You have a history of significant bleeding disorders or recent brain injury - You have severe psychiatric illness or recent substance abuse - You are currently enrolled in another clinical trial Talk to your doctor to see if this trial is right for you.