Vestibular impairment and adaptive postural imbalance in parkinsonian patients with lateral trunk flexion

Abstract

Lateral trunk flexion is a very common clinical observation in patients affected by Parkinson's disease. Postural control is known to depend on vestibular, visual, and somatosensory information. The aim of this study was to investigate whether impairment of vestibular function can account for the postural alterations observed in parkinsonian patients with lateral trunk flexion. We evaluated vestibular function in 11 parkinsonian patients with lateral trunk flexion and in 11 age-, sex-, and disease duration-matched patients without lateral trunk flexion. The following vestibular tests were performed: infrared videonystagmography including fast and slow ocular movements, spontaneous-positional and evoked nystagmus search with and without visual fixation, fast positioning maneuvers, the bithermal caloric test, and the vibration test. A peripheral, unilateral vestibular hypofunction was identified in all patients with lateral trunk flexion. The vestibular hypofunction was ipsilateral to the leaning side and contralateral to the most affected parkinsonian side in all patients. In the control group, 7 subjects had no vestibular signs; 4 subjects had unilateral vestibular hypofunction without clinically evident lateral trunk flexion. Two of the latter patients subsequently developed lateral trunk flexion ipsilateral to the vestibular deficit and contralateral to the side most affected by Parkinson's disease. The processing of vestibular information was impaired in parkinsonian patients affected by lateral trunk flexion. The impairment was at least in part responsible for the patients' postural abnormality. We propose that the acronym PISA (Postural Imbalance Syndrome with vestibular Alterations) be used to describe the specific postural change observed in parkinsonian patients affected by a vestibular defect and lateral trunk flexion.

Changes in postural control in patients with Parkinson's disease: a posturographic study

“…Previous studies have also shown reduced vestibular function in patients with PD [35], which was clinically characterised by vertigo, imbalance and/or falls.…”

Mood and behavioural effects of subthalamic stimulation in Parkinson's disease

“…54 Impairment in vestibular function ipsilateral to the leaning side was found in all patients with Pisa syndrome. Interestingly, 4 of 11 patients without Pisa syndrome presented impairments in vestibular function, and two of them later developed ipsilateral Pisa syndrome.…”

Visual deprivation elicits subclinical postural inflexibilities in early Parkinson's disease

“…Since the basal ganglia has a central role in the integration of the state of equilibrium to regulate motor commands appropriate to sensory experience, it is likely that this function cannot operate properly in patients with PD [19]. While vestibular dysfunction may play no or a minor role in PI in PD, many studies have supported the link between PI and the deficits in the proprioceptive function [17,[20][21][22]. On the other hand, the contribution of visual inputs is viewed as an adaptive strategy to compensate for the proprioceptive deficits [17].…”