Movement Disorders and Voice.

The primary movement disorders affecting the voice are laryngeal dystonia (including spasmodic dysphonia), essential voice tremor, and Parkinson disease. Diagnosis of these conditions is clinical and based on a detailed history, voice evaluation, and physical and laryngoscopic examination. Laryngeal dystonia and essential voice tremor are hyperfunctional disorders and are treated most commonly with botulinum toxin injections. Parkinson disease is a hypofunctional disorder that may affect the voice and most commonly is treated with Lee Silverman Voice Treatment.