Identifying subtypes of treatment effects of subthalamic nucleus deep brain stimulation on motor symptoms in patients of late-stage Parkinson’s disease with cluster analysis

Parkinson's disease (PD) presents clinical heterogeneity in late-stage patients who show a varied responsivity to subthalamic nucleus deep brain stimulation (STN-DBS) on motor symptoms. To explore the heterogeneity of STN-DBS effect on motor symptoms in late-stage PD patients and to categorize the patients, basic characteristics, preoperative motor symptoms, and motor symptoms one month and one year after the operation of 28 late-stage PD patients were collected and analyzed with agglomerative hierarchical clustering. Preoperative motor complications, non-motor symptoms, and late-stage related manifestations were also collected and compared among the clusters. The analysis revealed three patient clusters with different motor features: 1) high response; 2) low response, and 3) moderate response with fast progression. Clinical characteristics showed significant differences in disease duration, postoperative UPDRS-III, decrease in UPDRS-III, and index of progression. Patterns of the six major motor symptoms can clearly differentiate the three clusters. Preoperative dyskinesia, memory decline, and visual hallucination were also found to differ in the three clusters. The current study identified three clusters of late-stage PD patients showing distinct responses to STN-DBS on motor symptoms. These clustering patterns may relate with diverse dopaminergic/non-dopaminergic impairments and hopefully help to categorize late-stage PD patients and to select adequate STN-DBS candidates.