A localized pallidal physiomarker in cervical dystonia

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Deep brain stimulation (DBS) enables direct neuronal recordings in the human basal ganglia.
• A disease-specific physiomarker is utilized for adaptive closed-loop stimulation in Parkinson's disease.
• A similar biomarker is currently lacking for dystonia.

Purpose of the Study:

• To identify a potential physiomarker for dystonia using pallidal oscillations.
• To investigate the correlation between oscillatory amplitudes and dystonic symptom severity.
• To determine if theta oscillations can guide adaptive DBS in dystonia.

Main Methods:

• Recorded pallidal oscillations from 153 contact pairs in 27 dystonia patients.
• Analyzed theta and beta band power amplitudes for correlation with symptom severity.
• Mapped theta power to subcortical anatomy to define a 'theta hot spot' and assessed proximity for clinical improvement.

Main Results:

• Dystonic symptom severity significantly correlated with theta oscillations (ρ=0.4, p=0.009) and interhemispheric coherence (ρ=0.5, p=0.002).
• A 'theta hot spot' localized to the posterior internal pallidum, with proximity correlating to theta power (ρ=0.23, p=0.002).
• Motor improvement from chronic DBS correlated with theta peak amplitude (ρ=0.38, p=0.018).

Conclusions:

• Theta oscillations in the internal pallidum are strongly associated with dystonic symptoms.
• These oscillations may serve as a biomarker for adaptive closed-loop stimulation in cervical dystonia.
• Theta activity shows predictive value for DBS clinical benefit, potentially improving target mapping.