From the Guidelines
Prevalence of Vocal Tremor
The prevalence of vocal tremor is not explicitly stated in the provided evidence, but it can be estimated to be a subset of the prevalence of hoarseness, which has a lifetime prevalence of 29.9 percent and a point prevalence of 6.6 percent in adults aged 65 years or under 1. Vocal tremor can be a symptom of various conditions, including essential tremor, Parkinson's disease, and other neurological disorders.
- The evidence suggests that hoarseness, which includes vocal tremor, has significant public health implications, with patients suffering from social isolation, depression, and reduced disease-specific and general quality of life 1.
- Older adults are at particular risk, with a point prevalence of 29 percent and a lifetime incidence up to 47 percent of hoarseness 1.
- The treatment approach for vocal tremor depends on the underlying cause and severity of the condition, and may include medications such as beta blockers or botulinum toxin injections.
- However, the diagnostic validity of laryngeal electromyography (LEMG) for vocal tremor is unknown, and further studies are needed to determine its validity and reliability as a diagnostic tool 1.
From the Research
Prevalence of Vocal Tremor
- The prevalence of essential tremor (ET) is estimated to be around 0.9% in the general population, with a significant increase in prevalence with age, especially in those over 65 years old 2.
- Approximately 25% of patients with ET have vocal tract involvement, referred to as essential tremor of voice (ETV) 3.
- The prevalence of vocal tremor in the elderly population is not well established, but it is estimated to range from 4.8 to 29.1% in population-based studies 4.
- A study on essential voice tremor found that 93% of patients were female, and the average age of onset was 62.9 years old 5.
- Another study on isolated vocal tremor as a focal phenotype of essential tremor found that 89% of patients were female, and the average age of onset was 64 years old 6.
Characteristics of Vocal Tremor
- Vocal tremor is often characterized by kinetic laryngeal tremor that extends beyond the larynx to involve the phonatory apparatus globally 5.
- Patients with vocal tremor may experience significant physical and psychosocial disability, and the condition can be misdiagnosed or underdiagnosed 5, 6.
- A family history of tremor and improvement in tremor after consuming alcohol can often be elicited on history in patients with vocal tremor 6.
- The Vocal Tremor Scoring System (VTSS) is a tool used to assess the severity of vocal tremor, and it has been shown to be reliable and effective in predicting treatment outcomes 3.