Laryngeal Tremor Clinical Presentation

Updated: Apr 06, 2021
  • Author: Thomas L Carroll, MD; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Often, the voice disorder present is diagnosed based on history findings alone. Onset of vocal tremor, aggravating and alleviating factors, associated neurologic symptoms, medications, and family history are important components of the patient history. A history of multiple neurologic findings may suggest that the laryngeal tremor is secondary to another disease. The patient should be asked about specific vocal symptoms, such as the following:

  • Tremor

  • Vocal fatigue

  • Pain with speaking

  • Increased effort

  • Hoarseness

  • Pitch breaks

Patients who are seen with concerns for vocal tremor may in fact have symptoms of adductor or abductor spasmodic dysphonia or a combination of ETV and spasmodic dysphonia. Adductor dysphonia is characterized by phonatory breaks, hoarseness, monotonal pitch, and a strained voice quality. A breathy voice quality and trouble with voiceless consonants (/p/, /t/, /l/, /h/, /f/, /s/) are associated with abductor dysphonia. This distinction must be made, as treatment and prognosis are different.

Essential tremor is often seen alongside systemic manifestations of the disease characterized by postural or kinetic tremor of the upper extremities and head. Symptoms in patients with ETV slowly worsen over months and years. Voice tremor increases with anxiety and improves after alcohol ingestion. A study by Paige et al found the median frequency of ETV to be between 4 and 5 Hz, as measured with three different techniques (the perceptual, computerized peak detection, and laryngeal electromyography methods). [11]

Patients with Parkinson disease may experience the following symptoms in addition to a soft, breathy voice with or without a laryngeal tremor:

  • Limb tremor

  • Bradykinesia

  • Rigidity

  • Poor articulation

  • Difficulty initiating speech


Physical Examination

A thorough physical examination, including otolaryngologic and neurologic components, should be performed, with special attention paid to the neurologic examination of the mouth, pharynx, and larynx, as well as the evaluation of the voice. The assessment of vocal quality during conversational speech may enable the examiner to make a working diagnosis based only on the history and the sound of the patient’s voice. [12]

A neurolaryngeal examination, at rest and during phonation, is performed with a flexible laryngoscope (see Dynamic Voice Evaluation Using Flexible Endoscopy). Spontaneous rhythmic muscular activity of the laryngeal, supraglottic, and pharyngeal muscles while at rest is characteristic of tremor due to both Parkinson disease and ETV. However, tremor may also occur during sustained phonation in the case of ETV. Tremor should be differentiated from myoclonus, which is jerky and arrhythmic.

Full evaluation of the voice should include measures of fluidity, articulation, and voice quality (raspiness, breathlessness, strain). Phonatory tasks that isolate the abductor, adductor, and tensor muscle groups of the larynx allow the examiner to assess for paralysis, fatigability, and agility.

Bove et al developed a vocal tremor scoring system that standardized the evaluation and scaling of vocal tremor. [13] Furthermore, this system determined which patients were likely to benefit from botulinum toxin A (BTA) injection therapy. BTA injections are most helpful if the muscles causing the tremor are few and the injection would be focused. Global tremor involving the pharynx, tongue, and larynx is not often helped by BTA injections.