Higher Level Gait Disorders in the Elderly Subject: Postural Instability, Cortical and Subcortical Abnormalities (P06.077)

Abstract

Objective: In this study, we aimed to understand the physiopathology of these higher level gait disorders. Background The gait and balance disorders with falls are a major public health problem in the elderly population. In 10-20% of elderly people, these disorders are of unknown cause, and the term Higher Level Gait Disorders (HLGD) has been proposed. Design/Methods: Precise clinical evaluation, gait initiation analysis and brain imaging was performed in 20 patients with HLGD (mean age : 77 ± 6,8 years, mean disease duration : 3,9 ± 2,9 years), in comparison to 20 age-matched controls (mean age :77,3 ± 6,4 years). Results: HLGD patients showed parkinsonian symptoms with in particular an axial involvement (rigidity, freezing of gait and falls), without dementia or dysautonomia or supranuclear palsy. In HLGD patients compared to controls, step length, velocity and braking capacity (balance control) during the first step were reduced (-25%, -55% and -45%, respectively). A positive correlation was found between parenchymal volumes and step length and velocity, and the midbrain surface and the braking index. Compared to controls, patients with HLGD had a midbrain and primary motor cortex atrophy. Conclusions: In patients with so-called HLGD, imaging data are in favor of a degeneration of the structures classically described as affected in progressive supranuclear palsy (PSP). These data suggest that HLGD may in fact represent a very slow progressive form of this disease which has been recently described. Disclosure: Dr. Welter has nothing to disclose. Dr. Demain has nothing to disclose. Dr. Westby has nothing to disclose. Dr. Bonneville has nothing to disclose. Dr. Do has nothing to disclose. Dr. Tezenas Du Montcel has nothing to disclose. Dr. Dormont has nothing to disclose. Dr. Agid has nothing to disclose. Dr. Fernandez-Vidal has nothing to disclose. Dr. Chastan has nothing to disclose.