Eight cylindrical contact lead recordings in the subthalamic region localize beta oscillations source to the dorsal STN

Idit Tamir; Doris Wang; Witney Chen; Jill L. Ostrem; Philip A. Starr; Coralie de Hemptinne

Neurobiology of Disease (Dec 2020)

Eight cylindrical contact lead recordings in the subthalamic region localize beta oscillations source to the dorsal STN

Idit Tamir,
Doris Wang,
Witney Chen,
Jill L. Ostrem,
Philip A. Starr,
Coralie de Hemptinne

Affiliations

Idit Tamir: Philip Starr Laboratory, Department of Neurosurgery, University of California, San Francisco, California, USA; Corresponding author at: Department of Neurosurgery, Rabin Medical Center, 39 Zabotinski St., Petach Tikva, Israel.
Doris Wang: Philip Starr Laboratory, Department of Neurosurgery, University of California, San Francisco, California, USA
Witney Chen: Philip Starr Laboratory, Department of Neurosurgery, University of California, San Francisco, California, USA
Jill L. Ostrem: Department of Neurology, University of California, San Francisco, California, USA
Philip A. Starr: Philip Starr Laboratory, Department of Neurosurgery, University of California, San Francisco, California, USA
Coralie de Hemptinne: Philip Starr Laboratory, Department of Neurosurgery, University of California, San Francisco, California, USA

Journal volume & issue: Vol. 146
p. 105090

Abstract

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Background: In Parkinson's disease (PD) patients, the subthalamic nucleus (STN) has prominent oscillatory activity in the beta band, which may be related to the motor symptoms severity. Local field potential (LFP) studies using standard four-contact deep brain stimulation (DBS) leads indicate that the source of beta activity in the STN region is the dorsolateral segment of the nucleus. However, these leads have few contacts outside of the STN, making the source localization of beta activity around the STN region uncertain. Objective: This study aimed to investigate the electrophysiological characteristics of the STN and the surrounding area in PD to better locate the source of these oscillations and their clinical relevance. Methods: Eight PD patients were bilaterally implanted in the STN with the eight ring-contact DBS lead (Boston Scientific Corporation). LFPs were recorded intra-operatively from each DBS contact in the off medication state at rest. Each contact location was normalized relative to the STN borders based on microelectrode recordings. For each recording, power spectral density was computed, averaged over multiple frequency bands and phase reversal analysis was used to localize the source of oscillatory activity. Beta burst, high-frequency activity (HFA), and phase-amplitude coupling (PAC) were also computed. Neurophysiological signatures were correlated with hemibody symptoms severity and clinical outcomes. Results: Beta band power and phase reversal localized the beta oscillator to the dorsal STN and correlated with pre-operative off medication hemibody bradykinesia and rigidity score.The contact along the electrode with the largest beta oscillatory power co-localized with the independently chosen optimized contact used for long-term chronic DBS. Lastly, beta bursting, HFA, and Beta-HFA PAC co-localized with the beta oscillator at the dorsal STN, and Beta-HFA PAC correlated with DBS effect. Conclusions: Our findings support the hypothesis that the primary source of beta oscillations is located in dorsal STN, and argue against the alternative hypothesis that beta activity in the STN region arises from volume conduction from other sources. We demonstrate intrinsic STN beta-HFA PAC as an independent marker of DBS effect.

Published in Neurobiology of Disease

ISSN: 0969-9961 (Print); 1095-953X (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry
Website: https://www.journals.elsevier.com/neurobiology-of-disease

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