Classification of vocal tremor using updated consensus-based tremor classification criteria

Area of Science:

• Neurology
• Otolaryngology
• Speech-Language Pathology

Background:

• Vocal tremor (VT) diagnosis relies on specific clinical features.
• Standardized classification criteria are essential for accurate diagnosis and research.

Purpose of the Study:

• To characterize the clinical phenotypes of individuals with vocal tremor (VT).
• To assess the utility of International Parkinson and Movement Disorder Society (IPMDS) and American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria for VT classification.

Main Methods:

• Retrospective review of medical records (2017-2019) for 179 individuals with VT.
• Extraction of phenotypic descriptors including demographics, tremor characteristics, and comorbidities.
• Descriptive statistical analysis of collected data.

Main Results:

• 2/3 of participants were female; tremor onset affected voice (43%) or extremity (32%).
• Inadequate documentation of tremor features (e.g., observed condition, laryngeal features, frequency) was common (64-92%).
• 49% of VT classifications relied on comorbidities (essential tremor, dystonia, Parkinson's disease); 32% had insufficient data for classification.

Conclusions:

• Most individuals with VT could not be classified due to incomplete clinical documentation.
• Consistent, multidisciplinary assessment is crucial for evaluating tremors affecting speech structures.
• Commonly classified VT categories included essential tremor (47%), dystonia (28%), Parkinsonism (7%), and isolated VT (19%).