title: 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.
authors.affiliation: Università degli studi di Napoli Parthenope, Naples, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Vitale
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Marcelli
authors.forename: Teresa
authors.initials: T
authors.lastname: Furia
authors.forename: Gabriella
authors.initials: G
authors.lastname: Santangelo
authors.forename: Autilia
authors.initials: A
authors.lastname: Cozzolino
authors.forename: Katia
authors.initials: K
authors.lastname: Longo
authors.forename: Roberto
authors.initials: R
authors.lastname: Allocca
authors.forename: Marianna
authors.initials: M
authors.lastname: Amboni
authors.forename: Elio
authors.initials: E
authors.lastname: Marciano
authors.forename: Paolo
authors.initials: P
authors.lastname: Barone
mesh_terms: D000368:Aged; D002150:Caloric Tests; D016022:Case-Control Studies; D004421:Dystonia / Q000209:etiology*; D005133:Eye Movements; D005260:Female; D019416:Head Movements; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D009759:Nystagmus, Pathologic; D010300:Parkinson Disease / Q000150:complications*; D004856:Postural Balance / Q000502:physiology*; D012678:Sensation Disorders / Q000209:etiology*; D015837:Vestibular Diseases / Q000209:etiology*; D014724:Vestibular Function Tests