Vestibular Dysfunction in Parkinson's Disease: A Systematic Review of Signs and Symptoms.

BACKGROUND

Despite the growing interest in the link between Parkinson's disease (PD) neuropathology and vestibular system, there is still a lack of consensus about the presence of vestibular dysfunctions in PD.

OBJECTIVE

This review aims to identify vestibular signs and symptoms reported in PD patients and to summarize and critically appraise the measurement tools used to assess them.

METHODS

We searched at MEDLINE, Web of Science, Scopus, and PEDro databases until June 2023. All experimental or observational studies focused on evaluating vestibular signs or symptoms in PD patients were included. For clinical appraise of measurement tools previously published criteria were applied.

RESULTS

In total, 104 studies met the inclusion criteria. A total of 238 vestibular signs were identified, with the most frequently reported being nystagmus (n = 47, 19.7%) central oculomotor abnormalities (n = 47, 19.7%), vestibular evoked myogenic potentials impairments (n = 39, 16.4%), and postural control impairments (n = 37, 15.5%). A total of 27 vestibular symptoms were identified, with dizziness (n = 17, 63.0%) being the most frequently reported. Of the most commonly used, 6 were classified as "recommended," 14 as "suggested," and 5 as "listed."

CONCLUSIONS

Our findings raise awareness that vestibular signs and symptoms may be present in PD and should therefore be assessed comprehensively using the most suitable measurement tools. Future studies should focus on investigating the relationship between PD and the vestibular system, the progression of these signs and symptoms across disease stages, and the development of a standardized vestibular assessment protocol for PD to improve clinical management of these symptoms.