Parkinson's disease and the audiovestibular system

Abstract

Parkinson’s disease (PD) is a chronic neurodegenerative disorder primarily characterized by motor symptoms; however, the significance of non-motor manifestations is increasin­gly being recognized, with particular attention to hearing loss and imbalance. Although less apparent than motor symptoms, these issues can significantly impact patients’ quality of life and functional capacity. Various studies have shown a greater prevalence of senso­rineural hearing loss in individuals with PD compared to the age-matched general popu­lation. This hearing loss typically affects both peripheral and central auditory pathways, with high-frequency hearing deterioration, reduced transient evoked and distortion pro­duct otoacoustic emissions, and abnormalities in central auditory processing, including difficulty understanding speech in noisy environments. On the other hand, imbalance in PD is not solely related to the motor alterations inherent to the disease but may also invol­ve vestibular system dysfunction and impaired sensory integration. Although vestibular studies in PD remain limited, increased incidences of vertigo, postural instability, and falls have been reported, suggesting the presence of an underlying vestibular component that may be underdiagnosed. This review article aims to analyze the current scientific evidence on audiovestibular symptoms in PD and the findings of otoneurological exami­nations.