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. 2025 Jul 30;11(1):223.
doi: 10.1038/s41531-025-01090-0.

Effect of high, low, and asymmetric frequency subthalamic stimulation on speech and voice in Parkinson's disease: a randomized trial

Zhitong Zeng #  1 , Mei Yang #  1   2 , Zhengyu Lin #  1 , Peng Huang  1 , Yixin Pan  1 , Chencheng Zhang  3 , Bomin Sun  1 , Dianyou Li  4
Affiliations

Effect of high, low, and asymmetric frequency subthalamic stimulation on speech and voice in Parkinson's disease: a randomized trial

Zhitong Zeng et al. NPJ Parkinsons Dis. .

Abstract

While bilateral high-frequency subthalamic nucleus stimulation (Bi-HFS) frequently worsens speech in Parkinson's disease (PD), low-frequency stimulation (LFS) may alleviate gait deficits but lacks robust evidence for speech benefits. This randomized trial compared Bi-LFS (60 Hz) and Bi-HFS (130 Hz) in 33 PD patients with postural instability/gait difficulty (PIGD), and evaluated asymmetric frequency stimulation (AFS) in 20 patients. Bi-LFS significantly improved dysphonia severity index (DSI, FDR-p = 0.024), maximum phonation time (MPT, FDR- p = 0.025), and subjective speech ratings compared to Bi-HFS. Left-LFS/right-HFS (L-LFS/R-HFS) matched Bi-LFS efficacy and surpassed Bi-HFS in objective measures (FDR-p ≤ 0.021). Speech improvements correlated with motor/gait gains, independent of tremor. Findings suggest Bi-LFS mitigates speech dysfunction in PIGD-PD, with left-sided LFS potentially driving benefits, while AFS provides comparable outcomes. These data support tailored stimulation protocols to optimize speech in PD. The National Medical Research Registration and Information System of China (MR-31-23-036810).

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Conflict of interest statement

Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1. Flowchart of study design.
Stim-off, stimulation turned off; Bi, bilateral; HFS, high frequency stimulation; LFS, low frequency stimulation; AFS, asymmetric frequency stimulation; L left; R, right; ES, Evaluation session.
Fig. 2
Fig. 2. Voice and speech outcomes across Stim-off, Bi-HFS, and Bi-LFS conditions in Experiment Part I.
Stim-off, stimulation turned off; Bi, bilateral; HFS, high frequency stimulation; LFS, low frequency stimulation.
Fig. 3
Fig. 3. Voice and speech outcomes across Stim-off, Bi-HFS, Bi-LFS and AFS conditions in Experiment part II.
Stim-off, stimulation turned off; Bi, bilateral; HFS, high frequency stimulation; LFS, low frequency stimulation; AFS, asymmetric frequency stimulation; L left; R, right.
Fig. 4
Fig. 4. Correlation between motor and acoustic parameter changes across different stimulation conditions.
*, p < 0.05; ** p < 0.01; ***, p < 0.001; ****, p < 0.0001.
See this image and copyright information in PMC

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