Parkinsons Disease With Dementia (PDD)

This clinical trial aims to evaluate the clinical efficacy and safety of Deep Cervical Lymphaticovenous Anastomosis (DLVA) in patients aged 50-80 with moderate to severe neurodegenerative dementia. Participants will undergo surgical treatment, followed by cognitive assessments, PET/MRI scans, lymph fluid/cerebrospinal fluid collection, and blood tests. Additionally, the study will perform an in-depth analysis of DLVA's therapeutic mechanisms using multimodal imaging and molecular biology experiments.