Atypical somatosensory-motor cortical response during vowel vocalization in spasmodic dysphonia. Issue 6 (June 2019)

• Record Type: Journal Article
• Authors: Khosravani, Sanaz; Mahnan, Arash; Yeh, I-Ling; Watson, Peter J.; Zhang, Yang; Goding, George; Konczak, Jürgen
• Is Part Of: Clinical neurophysiology. Volume 130:Issue 6(2019:Jun.)
• Page Start: 1033
• Page End: 1040
• Publication Date: 2019-06
• Subjects: Dystonia -- Larynx -- Sensorimotor cortex -- Speech -- Voice disorder -- EEG coherence; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2019.03.003
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Inhibition of slow motor cortical rhythms during vocalization is reduced in spasmodic dysphonia. Somatosensory-motor cortical synchrony during vocalization is excessive in spasmodic dysphonia. Abnormal cortical processing in spasmodic dysphonia is mainly lateralized in the left hemisphere. Abstract: Objective: Spasmodic dysphonia (SD) is a debilitating voice/speech disorder without an effective cure. To obtain a better understanding of the underlying cortical neural mechanism of the disease we analyzed electroencephalographic (EEG) signals of people with SD during voice production. Method: Ten SD individuals and 10 healthy volunteers produced 50 vowel vocalization epochs of 2500 ms duration. Two EEG features were derived: (1) event-related change in spectral power during vocalization relative to rest, (2) inter-regional spectral coherence. Results: During early vocalization (500–1000 ms) the SD group showed significantly larger alpha band spectral power over the left motor cortex. During late vocalization (1000–2500 ms) SD patients showed a significantly larger gamma band coherence between left somatosensory and premotor cortical areas. Conclusions: Two atypical patterns of cortical activity characterize the pathophysiology of spasmodic dysphonia during voice production: (1) a reduced movement-related desynchronization of motor cortical networks, (2) an excessively large synchronization between left somatosensory and premotor cortical areas. Significance: The pathophysiology of SD is characterized by an abnormally high synchronous activity within and across cortical neural networks involved in voice production that is mainly lateralized in the left hemisphere.