title: Subjective Visual Vertical in PD Patients with Lateral Trunk Flexion.
abstract: Lateral trunk flexion (LTF) is a common phenomenon in patients with Parkinson's disease (PD) and has recently been associated with peripheral vestibular dysfunction. Since deviation of the subjective visual vertical (SVV) is a well-recognized feature of disorders involving vestibular processing, we analyzed SVV angles in 30 PD patients with and without LTF to assess the possible role of vestibular dysfunction in the pathogenesis of LTF in PD. Quantification of SVV was obtained using a simple bedside test. PD patients with LTF had significantly greater SVV angles as compared to PD patients without LTF (median: 4.3° [range: 0.1-17.7], n = 21, versus 0.8° [0.1-1.9], n = 9; p < 0.001). 14 of 21 patients with LTF showed pathological SVV, while all 9 patients without LTF had normal SVV. Abnormal SVV was more frequent when LTF was reversible in the supine position compared to fixed LTF. In a subgroup of PD patients with LTF, pathological SVV suggests vestibular dysbalance, which might be involved in the pathophysiological mechanisms underlying LTF.
authors.affiliation: Movement Disorders Clinic, Strasse nach Fichtenwalde 16, 14547 Beelitz-Heilstätten, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Gandor
authors.affiliation: Department of ENT, Trauma Hospital Berlin, Warener Strasse 7, 12683 Berlin, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Basta
authors.affiliation: Movement Disorders Clinic, Strasse nach Fichtenwalde 16, 14547 Beelitz-Heilstätten, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Gruber
authors.affiliation: Department of Neurology, Medical University of Innsbruck, Anichstrasse 25, 6020 Innsbruck, Austria.
authors.forename: W
authors.initials: W
authors.lastname: Poewe
authors.affiliation: Movement Disorders Clinic, Strasse nach Fichtenwalde 16, 14547 Beelitz-Heilstätten, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Ebersbach