Investigating the effect of STN-DBS stimulation and different frequency settings on the acoustic-articulatory features of vowels

• Published in: Neurological sciences Vol. 39; no. 10; pp. 1683 - 1689
• Main Authors: Yilmaz, Atilla, Sarac, Elif Tuğba, Aydinli, Fatma Esen, Yildizgoren, Mustafa Turgut, Okuyucu, Emine Esra, Serarslan, Yurdal
• Format: Journal Article
• Language: English
• Published: Milan Springer Milan 01-10-2018; Springer Nature B.V
• Subjects: Acoustics; Adult; Aged; Articulation Disorders - etiology; Articulation Disorders - physiopathology; Articulation Disorders - therapy; Deep brain stimulation; Deep Brain Stimulation - methods; Dopamine; Female; Follow-Up Studies; Humans; Magnetic resonance imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Movement disorders; Neurodegenerative diseases; Neurology; Neuroradiology; Neurosciences; Neurosurgery; Original Article; Otolaryngology; Parkinson Disease - physiopathology; Parkinson Disease - therapy; Parkinson's disease; Patients; Phonetics; Psychiatry; Software; Solitary tract nucleus; Speech; Speech Acoustics; Speech disorders; Statistical analysis; Subthalamic Nucleus - physiopathology; Surgery; Treatment Outcome; Variance analysis; Speech; Subthalamic nucleus; Acoustic-articulatory features; DBS; Deep brain stimulation; Parkinson’s disease
• ISSN: 1590-1874; 1590-3478
• DOI: 10.1007/s10072-018-3479-y

Introduction
Parkinson’s disease (PD) is the second most frequent progressive neuro-degenerative disorder. In addition to motor symptoms, nonmotor symptoms and voice and speech disorders can also develop in 90% of PD patients. The aim of our study was to investigate the effects of DBS and different DBS frequencies on speech acoustics of vowels in PD patients.
Methods
The study included 16 patients who underwent STN-DBS surgery due to PD. The voice recordings for the vowels including [a], [e], [i], and [o] were performed at frequencies including 230, 130, 90, and 60 Hz and off-stimulation. The voice recordings were gathered and evaluated by the Praat software, and the effects on the first (F1), second (F2), and third formant (F3) frequencies were analyzed.
Results
A significant difference was found for the F1 value of the vowel [a] at 130 Hz compared to off-stimulation. However, no significant difference was found between the three formant frequencies with regard to the stimulation frequencies and off-stimulation. In addition, though not statistically significant, stimulation at 60 and 230 Hz led to several differences in the formant frequencies of other three vowels.
Conclusion
Our results indicated that STN-DBS stimulation at 130 Hz had a significant positive effect on articulation of [a] compared to off-stimulation. Although there is not any statistical significant stimulation at 60 and 230 Hz may also have an effect on the articulation of [e], [i], and [o] but this effect needs to be investigated in future studies with higher numbers of participants.