Vocal Fold Tremor or Benign Essential Tremor is a neurologic disease that involves abnormal muscle contraction. The involuntary movements of the muscles result in a tremor or shake. Benign Essential Tremor causes the affected body part to shake while a person is attempting to perform an activity using that body part. It often affects the hands, thus making it difficult to grip utensils, write or perform other activities using the hands. Benign Essential Tremor can also involve the vocal folds, causing changes in the voice. The cause of this disease is not clearly comprehended.
Patients with Vocal Fold Tremor are unable to keep their voice steady. The sound of the voice has a rhythmic wobble, quavering or shake. The voice changes are not task specific and are always present with any type of vocalization. It is common for patients with Voice Tremor to adopt whispering as a standard mode of speaking, since it masks the symptoms.
There is no cure for Vocal Fold Tremor; the goal of treatment is to reduce the symptoms. In addition, there is not a universally accepted treatment method for Vocal Fold Tremor. Although medications have been very beneficial in treating Benign Essential Tremors involving other parts of the body, they have not proved as successful in Vocal Fold Tremor patients.
In severe cases, Botulinum toxin (Botox) injection into the vocal folds, through the skin of the neck, reduce the involuntary movement of the vocal folds by partially weakening them. By doing this, the abnormal contraction can be reduced, making speaking easier. The effects typically last several months and therefore, patients require lifelong injections to reduce the symptoms. The frequency of injections, as well as the dose given each time, varies for each patient. Voice therapy offers little relief, since the vocal fold motion is involuntary.