Tremor Reduction by Deep Brain Stimulation Is Associated With Gamma Power Suppression in Parkinson's Disease. Issue 5 (16th April 2015)

• Record Type: Journal Article
• Authors: Beudel, Martijn; Little, Simon; Pogosyan, Alek; Ashkan, Keyoumars; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Bogdanovic, Marko; Cheeran, Binith; Green, Alexander L.; Aziz, Tipu; Thevathasan, Wesley; Brown, Peter
• Is Part Of: Neuromodulaton. Volume 18:Issue 5(2015:Sep./Oct.)
• Page Start: 349
• Page End: 354
• Publication Date: 2015-04-16
• Subjects: Central nervous system -- Physiology -- Periodicals; Central nervous system -- Diseases -- Periodicals; 616.8
• DOI: 10.1111/ner.12297
• Languages: English
• ISSNs: 1094-7159

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="ner12297-sec-0001" sec-type="section"> <title>Objectives</title> <p>Rest tremor is a cardinal symptom of Parkinson's disease (PD), and is readily suppressed by deep brain stimulation (DBS) of the subthalamic nucleus (STN). The therapeutic effect of the latter on bradykinesia and rigidity has been associated with the suppression of exaggerated beta (13–30 Hz) band synchronization in the vicinity of the stimulating electrode, but there is no correlation between beta suppression and tremor amplitude. In the present study, we investigate whether tremor suppression is related to suppression of activities at other frequencies.</p> </sec> <sec id="ner12297-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>We recorded hand tremor and contralateral local field potential (LFP) activity from DBS electrodes during stimulation of the STN in 15 hemispheres in 11 patients with PD. DBS was applied with increasing voltages starting at 0.5 V until tremor suppression was achieved or until 4.5 V was reached.</p> </sec> <sec id="ner12297-sec-0003" sec-type="section"> <title>Results</title> <p>Tremor was reduced to 48.9% ± 10.9% of that without DBS once stimulation reached 2.5–3 V (t14 = −4.667, <italic>p</italic> < 0.001). There was a parallel suppression of low gamma (31–45 Hz) power to 92.5% ± 3% (t14 = −2.348, <italic>p</italic> = 0.034). This was not seen over a band containing tremor frequencies and their harmonic (4–12 Hz), or over the beta band. Moreover, low gamma power correlated with tremor severity (mean <italic>r</italic> = 0.43 ± 0.14, <italic>p</italic> = 0.008) within subjects. This was not the case for LFP power in the other two bands.</p> </sec> <sec id="ner12297-sec-0004" sec-type="section"> <title>Conclusions</title> <p>Our findings support a relationship between low gamma oscillations and PD tremor, and reinforce the principle that the subthalamic LFP is a rich signal that may contain information about the severity of multiple different Parkinsonian features.</p> </sec> </abstract>