title: High-level gait and balance disorders in the elderly: a midbrain disease?
abstract: The pathophysiology of gait and balance disorders in elderly people with 'higher level gait disorders' (HLGD) is poorly understood. In this study, we aimed to identify the brain networks involved in this disorder. Standardised clinical scores, biomechanical parameters of gait initiation and brain imaging data, including deep white matter lesions (DWML) and brain voxel-based morphometry analyses, were assessed in 20 HLGD patients in comparison to 20 age-matched controls. In comparison to controls, HLGD patients presented a near-normal preparatory phase of gait initiation, but a severe alteration of both locomotor and postural parameters of first-step execution, which was related to 'axial' hypokinetic-rigid signs. HLGD patients showed a significant grey matter reduction in the mesencephalic locomotor region (MLR) and the left primary motor cortex. This midbrain atrophy was related to the severity of clinical and neurophysiologically determined balance deficits. HLGD patients also showed a reduction in speed of gait, related to 'appendicular' hypokinetic-rigid signs and frontal-lobe-like cognitive deficits. These last two symptoms were correlated with the severity of DWML, found in 12/20 HLGD patients. In conclusion, these data suggest that the gait and balance deficits in HLGD mainly result from the lesion or dysfunction of the network linking the primary motor cortex and the MLR, brain regions known to be involved in the control of gait and balance, whereas cognitive and 'appendicular' hypokinetic-rigid signs mainly result from DWML that could be responsible for a dysfunction of the frontal cortico-basal ganglia loops.
authors.affiliation: Centre de Recherche de l'Institut du Cerveau et de la Moelle épiniere (CRICM), Université Pierre et Marie Curie-Paris 6, UMR-S975, Paris, France.
authors.forename: Adèle
authors.initials: A
authors.lastname: Demain
authors.forename: G W Max
authors.initials: GW
authors.lastname: Westby
authors.forename: Sara
authors.initials: S
authors.lastname: Fernandez-Vidal
authors.forename: Carine
authors.initials: C
authors.lastname: Karachi
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bonneville
authors.forename: Manh Cuong
authors.initials: MC
authors.lastname: Do
authors.forename: Christine
authors.initials: C
authors.lastname: Delmaire
authors.forename: Didier
authors.initials: D
authors.lastname: Dormont
authors.forename: Eric
authors.initials: E
authors.lastname: Bardinet
authors.forename: Yves
authors.initials: Y
authors.lastname: Agid
authors.forename: Nathalie
authors.initials: N
authors.lastname: Chastan
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Welter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001927:Brain Diseases / Q000150:complications*; D016022:Case-Control Studies; D004576:Electromyography; D005260:Female; D020233:Gait Disorders, Neurologic / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008124:Locomotion / Q000502:physiology; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000473:pathology*; D004856:Postural Balance / Q000502:physiology*; D012678:Sensation Disorders / Q000175:diagnosis / Q000209:etiology*; D018709:Statistics, Nonparametric