Brain Mapping of Voice Control
Condition: Voice Disorders
MeSH terms: Voice Disorders
Study type: Observational

Summary: 
      Some voice disorders are caused by uncontrolled muscle actions that affect the larynx or
      voice box.

      The purpose of this study is to understand 1) how the brain controls voice production; 2) how
      changes in sensation within the voice box affect brain control of the voice box; 3) how the
      central nervous system is affected when people have motor or sensory abnormalities that
      affect the voice box; and 4) whether patients with voice disorders differ from people without
      voice disorders in the way the brain controls the voice box. By better understanding these
      concepts, researchers hope to develop improved treatments for patients with voice disorders.

      Forty-five healthy adult volunteers and 90 patients with voice disorders will participate in
      this study. Participants must be between the ages of 20 and 70. The study will involve two
      visits to the Clinical Center. During the first visit, participants will undergo a medical
      history and physical exam. During the second visit, investigators will perform the following
      procedures on study participants: 1) look at the voice box with a nasolaryngoscope, a fine
      tube through the nose; 2) use MRI [magnetic resonance imaging] to record brain activity while
      participants use their voice to speak; 3) changing sensation in the voice box by dripping a
      topical anesthetic onto the vocal folds; and 4) using MRI to again record brain activity
      during speech immediately after applying the topical anesthetic.

      Participants will receive up to $700 in compensation for their involvement in this study.
    

Detailed description: 
      The neural organization of laryngeal motor and somatosensory function will be investigated in
      adults with idiopathic voice disorders using functional magnetic resonance imaging. Brain
      activation will be compared in normal volunteers and patients with spasmodic dysphonia (SD),
      muscle tension dysphonia (MTD) and vocal tremor. While each voice disorder is characterized
      by strained vocalization, the disorders are distinguished by other differences in voice
      symptoms. Accordingly, the brain correlates of vocalization in these disorders may both
      differ from each other and that of normal vocal function. Because sensory feedback has been
      identified as a factor in SD, the role of afferent input in vocalization will be investigated
      by comparing brain activation before and after topical anesthesia of the laryngeal mucosa.
      The afferent blockade is expected to significantly suppress dysphonic symptoms in SD patients
      for the duration of the block. The change in symptomatology may be associated with a
      temporary but significant change in central sensorimotor patterns in these patients. The
      block is not expected to alter MTD, vocal tremor or normal vocal function. The brain
      activation changes that accompany symptom relief in SD patients will determine alterations in
      central neural control that have a role in symptom generation in SD. Identifying these
      differences in central sensorimotor control between the disorders will provide insight into
      their differences in pathophysiology.

      Objectives:

        1. To determine if emotional vocalization and linguistic vocalization involve different
           cortical and sub-cortical functional networks in normal adults.

        2. To determine if only the brain activation network active for linguistic vocalization
           network differs between normal controls and dysphonia patients during equivalent voice
           production effort.

        3. To determine if patients with dysphonia differ from controls during the performance of
           non-vocal laryngeal gestures when patients are asymptomatic.

        4. To determine if a reduction in sensation during topical anesthesia alters linguistic
           vocalization in dysphonia but not in controls.
    

Keywords: Functional Magnetic Resonance Imaging; Vocalization; Spasmodic Dysphonia; Muscular Tension Dysphonia; Topical Lidocaine; Voice Disorders; Vocal Tremor; Healthy Volunteer; HV