Vocal tremor involves an unstable voice. It can occur in isolation or in combination with other neurological disorders such as, for example, laryngeal dystonia.
WHAT IS VOCAL TREMOR?
Vocal tremor may occur alone or in combination with other neurologic conditions, particularly laryngeal dystonia. About 10% of patients with laryngeal dystonia or spasmodic dysphonia also have vocal tremor. A general sense I have about vocal tremor is that typically, patients are not bothered by their unsteady voice. More commonly someone they know, friend or family, inquires about their unsteady voice. Typically, to the patient, speaking is not effortful. This is in contrast to laryngeal dystonias, where quite often, the patient senses a great deal of effort to speak, when others may not even notice the change of quality in their voice.
WHAT ARE THE CAUSES?
The cause of vocal tremor is unknown, but is inherited in almost half of the cases.
WHAT ARE THE RISK FACTORS?
Vocal tremor is often inherited and gets worse with age.
HOW ABOUT THE EXAMINATION?
The voice organ and its function are examined by an ENT doctor and a speech therapist. The voice has 3 functions: breathing, protecting the airway while swallowing and speaking. Every person is dependent on these 3 functions every moment of the day.
In addition to a thorough survey and a clinical examination of the neck, an inspection of the vocal cords (laryngoscopy) takes place at rest and during vocalization. This is supplemented by a stroboscopy, research in which through short flashes of light, the vibration pattern of the vocal cords is delayed and thus displayed in more detail.
Then, the voice and voice capacity is listened to. One can often hear the nature of the voice problem while speaking. Sliding, softer or louder voices, soft singing can help to find the right cause of the weak or painful voice.
In addition, a voice examination usually takes place, including aerodynamic parameters (the maximum phonation time), acoustically perceptual parameters (e.g. habitual speech pitch, voice quality in function of the change intensity and pitch) and the vocal range (intensity and frequency dynamics).
If the cause or complete diagnosis is not yet clear, additional studies may be appropriate. Percutaneous electromyography (E.M.G.) can provide additional information about muscle activity and innervation of laryngeal muscles. Radiological examinations (e.g. RX of the lungs or CT neck) can demonstrate a local cause of vocal cord paralysis.
Vocal tremor can often be treated through medication. Regular monitoring by the doctor for adjusting the correct (quantity and type specific per individual) is recommended. Often, the medication does not completely suppress the vocal tremor but does reduce it severely.