Subjective patient rating as a novel feedback signal for DBS programming in Parkinson's disease

Background

Deep brain stimulation of the subthalamic nucleus (STN-DBS) effectively alleviates motor fluctuations in Parkinson's disease (PD). Optimal electrode placement and effective programming significantly influence outcomes. From a patient's perspective, DBS should relieve motor symptoms while avoiding side effects. However, there is a lack of programming routines that consider patients' subjective feedback for parameter adjustment.

Objective

This study assessed the usefulness of patients' subjective ratings as feedback for DBS programming.

Methods

We analyzed 260 DBS settings from 11 STN-DBS patients, pairing each volume of tissue activated (VTA) with a subjective rating measured by a visual analogue scale (VAS). We performed sweet spot mapping and connectivity analyses, utilizing voxel-wise and nonparametric permutation statistics to identify neuroanatomical regions and connectivity profiles associated with the highest VAS ratings. To validate our findings, we cross-validated the results in an independent test dataset of 6 patients (189 settings) to determine if the sweet spot and connectivity profile could predict the subjective patient perception.

Results

VTAs with the highest VAS scores were localized to the dorsolateral STN, consistent with published sweet spots derived from clinical data. Connectivity with the supplementary motor area (SMA) and primary motor cortex (M1) was associated with a more positive subjective perception. Connectivity profiles derived from one dataset successfully predicted outcomes in an independent dataset, as validated through leave-one-cohort-out cross-validation.

Conclusions

Mapping patients' subjective perceptions using VAS yields conclusive anatomical results that align with objective clinical and imaging measures. VAS-guided programming could provide an additional feedback mechanism for both acute and chronic DBS parameter adjustments.