COMPREHENSIVE ASSESSMENT OF VOICE DISORDERS IN PARKINSON’S DISEASE USING THE VOICE HANDICAP INDEX AND ACOUSTIC VOICE ANALYSIS

Abstract

Parkinson’s disease (PD) and Parkinsonian syndromes are progressive neurodegenerative disorders associated with both motor and non-motor manifestations, including speech and voice impairment. Dysphonia and motor speech disorders significantly reduce communication abilities, social adaptation, and quality of life in affected patients. Early identification of phonatory dysfunction remains an important clinical challenge because voice abnormalities may appear at the initial stages of neurodegenerative disease progression. The aim of this study was to evaluate the diagnostic significance of the Voice Handicap Index (VHI) questionnaire and acoustic voice analysis in patients with Parkinson’s disease and Parkinsonian syndromes. The study included 120 participants, including 100 patients diagnosed with Parkinson’s disease or Parkinsonian syndromes and 20 healthy individuals who formed the control group. All participants underwent neurological, otorhinolaryngological, and phoniatric examination. Subjective evaluation of voice disorders was performed using the Uzbek-adapted version of the Voice Handicap Index questionnaire (VHI-uz). Acoustic voice analysis included evaluation of dysdiadochokinesis, shimmer, jitter, tremor characteristics, phonatory stability, vocal intensity, articulation disturbances, respiratory coordination, and frequency variability. Patients with Parkinson’s disease demonstrated significant motor speech impairment characterized by hypophonia, monotony, impaired articulation, reduced phonatory stability, and decreased speech intelligibility. Acoustic analysis revealed pathological changes in shimmer and jitter parameters reflecting instability of vocal fold vibration and impaired neuromuscular control of phonation. Dysdiadochokinetic testing showed impaired coordination and reduced speech motor speed in patients with Parkinsonian syndromes compared with healthy individuals. According to VHI assessment, patients with Parkinson’s disease had significantly more severe functional and emotional disturbances compared with the control group. Functional impairment included reduced communicative ability and vocal efficiency, whereas emotional disturbances included anxiety, frustration, embarrassment, and social discomfort associated with voice disorders. The combined application of VHI and acoustic voice analysis is a sensitive, objective, and non-invasive diagnostic approach that may improve early diagnosis, differential assessment, and monitoring of Parkinsonian syndromes.