Sensorimotor Integration in Patients with Voice Disorders: A Scoping Review of Behavioral Research

In recent years, research has determined that impaired sensorimotor integration is a contributor to the formation of voice symptoms and voice disorders. A scoping review is undertaken to explore the current state of scientific research regarding behavioral examinations of sensorimotor integration impairments in patients.

Following the guidelines of the PRISMA Extension for Scoping Reviews, five online databases identified papers published between 2000 and 2023, from which 17 publications were selected that used sensorimotor integration paradigms with voice-related acoustics as an outcome variable in individuals diagnosed with a voice disorder. Across the 17 studies, sensorimotor integration was behaviorally examined via auditory-motor paradigms in 315 patients with voice disorders and 344 controls. Broadly, patients with vocal hyperfunction demonstrated impaired auditory-motor and somatosensory-motor integration. Patients with unilateral vocal fold paralysis demonstrated impaired sensorimotor integration attributed to changes in the primary brain areas of speech motor control. Patients with laryngeal dystonia demonstrated varying results, with no conclusive evidence regarding sensorimotor integration in behavioral voicing tasks. Patients with Parkinson's disease demonstrated varying results as well, with a general trend of increased dependance on the feedback control system of voice production. Patients with ataxic dysarthria demonstrated that auditory feedback control was impaired possibly due to inaccurate error estimation and correction arising from the damage to their cerebellar pathways. Finally, patients with cerebellar degeneration demonstrated disruptions in both feedback and feed-forward control.

Sensorimotor integration in the context of voice disorders is an important consideration in understanding how different sensory streams operate in healthy voice production, and how sensory feedback can be optimized in clinical treatments of voice disorders. The present scoping review reveals that behavioral research has focused primarily on auditory-motor integration paradigms, and this supports the possibility of a disconnect between these behavioral studies and existing theoretical conceptualizations of vocal motor control.