Abnormalities of vestibular-evoked myogenic potentials in idiopathic Parkinson’s disease are associated with clinical evidence of brainstem involvement

Abstract

Brainstem degeneration in Parkinson's disease (PD) may explain the occurrence of many non-motor symptoms in this condition. Purposes of the present work were to investigate brainstem function in PD through a battery of vestibular-evoked myogenic potentials (VEMP) allowing a comprehensive brainstem exploration and to correlate VEMP findings with symptoms related to brainstem involvement. Cervical (cVEMP), masseter (mVEMP) and ocular (oVEMP) VEMPs were investigated in 24 PD patients and compared with those recorded in 24 age-matched controls. Presence of symptoms ascribable to brainstem dysfunction, such as daytime sleepiness, REM sleep behavior disorder and depression, was investigated through Epworth Sleepiness Scale, Parkinson's Disease Sleep Scale, REM Sleep Disorder Screening Questionnaire (RBD-SQ) and Geriatric Depression Scale. Postural instability was additionally assessed through mini-BESTest. The frequency of alteration of VEMPs in patients was 83.3 % when considering the whole set and 41.7 % for cVEMP, 66.7 % for mVEMP and 45.8 % for oVEMP. This was significantly different from controls, with absence being the prevalent alteration in PD. A significant inverse correlation between the number of altered VEMPs and mini-BESTest and a direct correlation with RBD-SQ were found. The VEMP battery under study allowed the identification of brainstem dysfunctions in PD patients, which correlated with clinical tests suggestive of postural and REM sleep disorders. VEMPs might represent a valuable tool of brainstem assessment in PD.

Neurovestibular analysis and falls in Parkinson's disease and atypical parkinsonism

“…Recent studies by De Natale et al . (,b) in groups of 33 and 24 PD patients in total showed significantly more abnormal individual masseter, ocular and cervical VEMPs in comparison with an age matched control group ( P < 0.001). At the group level the amplitudes of, in particular, the masseter and ocular VEMPs were significantly smaller in comparison with the healthy control subjects, and the individual results showed a significant correlation with postural instability and rapid eye movement sleep behaviour disorder screening scores.…”

Intrarater and interrater agreement and reliability of vestibular evoked myogenic potential triggered by galvanic vestibular stimulation (galvanic-VEMP) for HTLV-1 associated myelopathy testing

“…The motor reflexes that are evoked to maintain the postural equilibrium can be captured by surface electromyography (EMG) in the body muscles involved in one’s posture. Galvanic-VEMP evaluates the brainstem function, as other VEMPs do [ 35 ], and further assesses the vestibulospinal motor tract. The chosen muscle to record the electrophysiological sign defines the tested level of the spine.…”

Aplicações dos potenciais evocados miogênicos vestibulares: revisão sistemática de literatura

“…According to the authors, these findings suggest reduction in the reflexes that correlate with the vestibular activity (15) . Another study showed changes in cervical and ocular VEMP responses in patients with Parkinson's disease and postural instability (43) .…”

“…The studies about VEMP with auditory stimulation have evidenced this test as an assisting tool for the diagnosis of several types of peripheral vestibular disorders, predominantly Meniere's disease (5,6,29,40) and superior semicircular canal dehiscence (SSCD) (8)(9)(10)(11)32) , as well as diseases related to central vestibular disorders, such as motor myelopathies (19)(20)(21)(22)(23)(24)(25) and Parkinson's disease (15,(41)(42)(43) .…”