FEATURES OF BIOELECTRIC ACTIVITY OF THE BRAIN IN FUNCTIONAL DYSPHONIA AND ORGANIC PATHOLOGY OF THE LARYNX

Abstract

Abstract

Introduction. Voice disorders significantly reduce the quality of life and professional capabilities of voice-speech professionals. Phonation is maintained by an integrated system under the coordinating control of the central nervous system (CNS). Functional voice disorders are frequently associated with autonomic dysfunction and psychoemotional instability, which justifies the pathogenetic reason for neurophysiological monitoring via electroencephalography (EEG).

Objective. To investigate the features of brain bioelectric activity using electroencephalography data in patients with functional dysphonia and organic larynx pathology.

Materials and Methods. The study examined 120 patients with voice disorders divided into four clinical groups: Group 1 – 25 individuals with mild functional hypotonic dysphonia (FHD); Group 2 – 30 patients with moderate FHD; Group 3 – 34 patients with complicated FHD (pre-nodular state, vocal fold nodules, thinning of the medial edge); Group 4 – 31 patients with a combination of FHD, organic larynx pathology, and vestibular hypertonus. The control group consisted of 15 healthy individuals. EEG recording was performed using the international "10–20" system at rest and during functional trials (photostimulation, hyperventilation).

Results. Visual and quantitative EEG analysis revealed diffuse changes in cortical activity in all patients with FHD. In Groups 1 and 2, signs of cortical irritation prevailed (β-activity and bursts of disorganized α-rhythm with sharp wave contours). In Groups 3 and 4, the pathological process transformed into severe dysfunction of the deep diencephalic and diencephalic-brainstem structures, accompanied by paroxysmal bursts, "sharp wave — slow wave" complexes, and a significant (sometimes sharp) decrease in the EEG signal amplitude. Pathological patterns were registered even during the baseline recording and critically increased during the 3rd minute of hyperventilation, correlating with a high frequency of somatoform complaints (cephalgia, insomnia, irritability) in the advanced groups.

Conclusions. A direct relationship was established between the depth of CNS neurophysiological disorders and the severity of vocal apparatus impairment. The recorded EEG patterns demonstrate a transition from isolated cortical irritation to deep unbalancing of subcortical regulatory centers during disease chronization, serving as a prognostically significant criterion for optimizing customized medical, diagnostic, and rehabilitation protocols.