Category: Parkinson's Disease: Surgical Therapy
Objective: To explore the presence and significance of finely tuned gamma in the globus pallidus internus (GPi) in Parkinson’s disease (PD).
Background: PD is a progressive neurodegenerative disease, and motor fluctuations such as wearing-off and dyskinesia are problematic in the advanced stages. Recently, local field potential (LFP) oscillations in the finely tuned gamma (FTG, 60-90 Hz) band recorded in subthalamic nucleus after deep brain stimulation (DBS) have been correlated with dyskinesias and the ‘on state’, but little is known about FTG activity in GPi.
Method: We present a case report of a 67-year-old man with PD who underwent staged bilateral GPi-DBS for the management of dyskinesias and motor fluctuations. The patient was implanted with a DBS device that allows chronic brain sense (Percept, Medtronic, Minneapolis, MN). Since the DBS implanted, the patient attended nine times in-clinic visits for DBS programming, during which LFPs were recorded. The raw time series LFPs were converted into spectral features using power spectral density estimation methods. The spectral features were then used to identify the presence of FTG. In addition, the severity of the symptoms, the presence of dyskinesia, and the therapeutic conditions (medication and stimulation state) were collected from each DBS programming visit.
Results: FTG was present in all recordings done in the on-medication state but were absent when in the off-medication state. The patient was documented to have dyskinesias in clinic during most on-medication visits. The mean frequency of FTG was 73.8 (70.0 – 77.0) Hz in left GPi and 75.9 (74.0 – 79.0) Hz in right GPi and shifted to half the stimulation frequency when the DBS was turned on.
Conclusion: We report for the first time the presence of FTG in the GPi in a patient with PD. Similar to what has been observed in the STN and motor cortex, GPi FTG might be a marker of ‘on state’ or dyskinesia and is entrained by stimulation. Future studies exploring the prevalence of FTG in GPi is needed to fully understand its significance and role in dyskinesia.
To cite this abstract in AMA style:
H. Kamo, J. Cagle, K. Johnson, M. Eisel, J. Wong, C. Hemptinne. Exploring pallidal gamma oscillations in Parkinson’s disease: A case report [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/exploring-pallidal-gamma-oscillations-in-parkinsons-disease-a-case-report/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/exploring-pallidal-gamma-oscillations-in-parkinsons-disease-a-case-report/