Life Neuroscience

Parkinson’s disease (PD) is a degenerative movement disorder, resulting in tremors, rigidity, bradykinesia, posture instability, and even dementia. Medical therapy (MT), or dopaminergic medications are the first line of treatment. Surgical deep brain stimulation (DBS) is becoming the preferable treatment approach. This review was done to compare the clinical, functional, and other main outcomes between DBS and MT in PD, focusing also on globus pallidus internus (Gpi) and subthalamic nucleus (STN) stimulation. PubMed was searched for articles that compare between DBS and MT, using keywords such as “parkinson’s disease”, “medical therapy”, and “deep brain stimulation”. Analysis was performed synthesizing data from 21 studies, 6 of which are randomized clinical trials (2017-2021). Of the 21 included studies, deep brain stimulation plus medical therapy achieved superior efficacy compared with medical therapy alone, in terms of quality of life, functional and motor outcomes. DBS plus best medical therapy yielded clinically significant improvements in the Parkinson's Disease Questionnaire (PDQ-39) Summary Index, reporting a mean improvement of 4.7 points compared to MT. Both STN and Gpi stimulation provided comparable long-term motor benefits, GPi-DBS was better with neurocognitive function and motor complications, while STN-DBS was better with medication outcomes. DBS is a highly effective treatment that should be considered when there are motor deficits to maximize quality of life and functional independence. The choice of target should be individualized; STN-DBS is better for patients prioritizing maximal medication reduction, while GPi-DBS is preferable for patients with pre-existing cognitive or mood concerns.