Abstract
OBJECTIVE: Clinical rating scales often fail to capture the full spectrum of dystonic symptoms. Deep brain stimulation of the globus pallidus interna (GPi-DBS) effectively treats dystonia, but response variability necessitates a reliable biomarker. Intermuscular coherence (4-12 Hz) has been linked to abnormal activity in the cortico-basal ganglia-thalamo-cortical (CBGTC) loop and may serve as an objective measure of dystonia and GPi-DBS effectiveness.
METHODS: A retrospective cohort study included 12 dystonia patients undergoing GPi-DBS implantation. Clinical rating scales and a neurophysiological assessment were performed before and one year post-DBS. Coherence in the 4-12 Hz range was analyzed from electromyography (EMG) of antagonistic arm muscles. Comparisons were made between patients with and without arm dystonia, t-tests evaluated the differences between pre- and post-DBS, and correlations between coherence and clinical scales were performed.
RESULTS: Seven patients with arm dystonia appeared to have higher pre-operative intermuscular coherence compared to those without. Coherence was significantly decreased after GPi-DBS in the arm dystonia group. No strong correlations were found between coherence and clinical rating scales.
CONCLUSION: Intermuscular coherence is present in dystonic muscles and decreases following GPi-DBS. Correlations with motor scores were inconclusive due to patient heterogeneity and ill-fitting clinical scales.
SIGNIFICANCE: Intermuscular coherence has potential to aid GPi-DBS patient selection and optimization but larger studies are needed to validate its use.
Original language | English |
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Pages (from-to) | 70-79 |
Number of pages | 10 |
Journal | Clinical Neurophysiology |
Volume | 170 |
Early online date | 14-Dec-2024 |
DOIs | |
Publication status | Published - Feb-2025 |
Keywords
- Biomarker
- DBS efficacy
- Dystonia
- GPi-DBS
- Intermuscular coherence