Stimulation-related increases in power spectral density covary with clinical evidence of overstimulation during deep brain stimulation for pediatric dystonia.

Background: Dystonia patients undergoing deep brain stimulation (DBS) often require individualized stimulation settings. While effective settings reduce dystonia, excessive stimulation can worsen symptoms. Assessing DBS effects during office visits is challenging, as clinical changes can be delayed hours to days.

Objective: We evaluated whether local field potentials (LFPs) could serve as an acute biomarker of excessive stimulation in dystonia patients.

Methods: Real-time LFP band power and dystonia severity were quantified and compared during sequential changes in stimulation amplitude.

Results: Dystonia worsening was temporally associated with clinically evident and statistically significant increases in LFP band power during in-office DBS programming sessions.

Conclusions: Although increased LFP band power correlated with clear clinical worsening in these patients, we anticipate that not all patients with dystonia will have such immediate signs of worsening. Increased LFP band power during incremented stimulation amplitude may represent a biomarker for patients at-risk of manifesting delayed clinical worsening.