Functional magnetic resonance imaging study of
central neural system control of voice, with emphasis
on phonation in women with muscle tension dysphonia
M. Kryshtopava1, K. Van Lierde2,3, I. Meerschman2, E. D’Haeseleer2, G.
Vingerhoets4, S. Claeys1
1The
2The
Department of Otorhinolaryngology, University Hospital Ghent, Ghent, Belgium;
Department of Speech, Language and Hearing Sciences, University Hospital Ghent, Ghent,
Belgium;
3Department
of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria,
South Africa
4Faculty
of Psychology and Educational Sciences, Ghent University, Belgium
Introduction and aim:
The prevalence of functional dysphonia in the working-age population (25 – 64 years) seeking
consultation in an ENT department is 41% and female professional voice users are
predominantly affected (43% women vs. 36% men). The term muscle tension dysphonia (MTD)
is often used to describe functional voice disorders with vocal hyperfunction that can be defined
as the involvement of too much muscle force and physical effort during phonation. It is caused
by incoordination of muscles, or excessive muscle usage in phonation. The neurophysiological
mechanism of laryngeal tension in MTD remains unexplored. Neuroimaging techniques are
becoming important objective tool to describe neural networks associated with laryngeal control
of phonation. This study aims to investigate the neural control of phonation and exhalation in
women with MTD in comparison with healthy controls using the proposed fMRI protocol.
Material and methods:
Ten women with MTD and fifteen healthy women participated in this study. The fMRI
experiment was carried out using a block design paradigm. Brain activation during phonation
and exhalation was analyzed using Brain Voyager software.
Results
The statistical analysis of fMRI data has demonstrated that MTD patients control phonation by
use of the auditory, motor, frontal, parietal, and subcortical areas similar to phonation control by
healthy people. Comparison of phonation tasks in the two groups revealed higher brain activities
in the precentral gyrus, inferior, middle and superior frontal gyrus, lingual gyrus, insula,
cerebellum, midbrain, and brainstem as well as lower brain activities in the cingulate gyrus,
superior and middle temporal gyrus, and inferior parietal lobe in the MTD group. No differences
were found between two groups regarding exhalation control.
Conclusions
The findings in this study provide insight into phonation and exhalation control in patients with
MTD. The imaging results demonstrated that in patients with MTD, altered (higher/lower) brain
activities may result in laryngeal tension and vocal hyperfunction.