From the Guidelines
Laryngeal tremor is a neurological condition characterized by involuntary movements of the vocal folds and surrounding laryngeal muscles, often presenting as a voice tremor, and can be associated with other neurological disorders such as essential tremor syndrome, Parkinson's disease, or dystonia.
Definition and Presentation
This condition typically causes shakiness or quivering in the voice during speech, and patients may experience voice breaks, difficulty maintaining steady phonation, and increased vocal effort. According to 1, the diagnosis can be subtle and may masquerade as other forms of dysphonia, leading to significant delays in diagnosis.
Pathophysiology and Diagnosis
The underlying mechanism involves abnormal neural signals from the central nervous system that affect the laryngeal motor control. Diagnosis typically requires laryngoscopic examination during various vocal tasks to differentiate it from other voice disorders, as noted in 1.
Treatment Options
Treatment options for laryngeal tremor include voice therapy to improve vocal technique and reduce strain, and botulinum toxin (Botox) injections into the laryngeal muscles to reduce tremor amplitude. The use of botulinum toxin is supported by a high level of evidence, with a preponderance of benefit over harm, as stated in 1.
- Key considerations for treatment include:
- The potential need for repeated treatments with botulinum toxin
- The importance of patient preferences in treatment decisions
- The exclusion of patients with an allergy to botulinum toxin
- The condition is often progressive but can be managed effectively with appropriate interventions, as noted in 1.
From the Research
Definition and Characteristics of Laryngeal Tremor
- Laryngeal tremor, also known as essential vocal tremor, is a neurologic disorder that affects the voice, causing tremors or shaking in the laryngeal muscles 2, 3, 4, 5.
- The condition is characterized by kinetic laryngeal tremor, which can extend beyond the larynx to involve the phonatory apparatus globally 5.
- Essential vocal tremor can be classified into different types, including horizontal and vertical laryngeal tremor, and can co-occur with other conditions such as spasmodic dysphonia and laryngopharyngeal reflux disease 2, 3, 4.
Clinical Features and Diagnosis
- The clinical features of essential voice tremor include a mean Vocal Tremor Scoring System (VTSS) score of 7.7 +/- 3.3, and a mean Voice Handicap Index (VHI) score of 71 +/- 28 5.
- The condition typically begins in the seventh decade of life, and has been present for a mean of 6.7 +/- 13.4 years at the time of presentation 5.
- Diagnosis can be challenging, and many cases are undiagnosed or misdiagnosed, often as spasmodic dysphonia 5.
Treatment Options
- Treatment options for essential vocal tremor include botulinum toxin injections, which can be effective in reducing tremor amplitude and improving voice quality 3, 4, 5.
- Other treatment options, such as primidone therapy, have also been explored, but the evidence is limited and inconclusive 2.
- The effectiveness of treatment can vary depending on the individual patient and the specific characteristics of their tremor, such as the presence of horizontal and vertical components 4.