Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by an expanded CAG repeat. The clinical features are progressive motor dysfunction, cognitive deterioration, and psychiatric disturbances. Unpredictable choreic movements, among the most characteristic hallmarks, may contribute to gait disturbances and loss of balance in HD individuals. In this study, we aimed to investigate and characterize the gait abnormalities and choreic movements in a transgenic rat model of HD (tgHD). TgHD presents typical neuropathological, neurophysiological, and behavioral aspects mimicking some of the key features of human HD and is the only described experimental model for HD that exhibits choreiform movements. We used the Catwalk, with emphasis on static and dynamic gait parameters, to test the hypothesis that at symptomatic age (9 months) the dynamic measures of gait in HD are altered and coexist with choreiform movements. Our results showed that the dynamic parameters seem to be more affected than static parameters at this age in tgHD rats. The number of steps and step cycles and swing speed of the paws were increased in tgHD rat in comparison to wild-type controls. Our study demonstrates that gait abnormalities coexist with chorea rather than being caused by it. These symptoms may originate from distinct networks in the basal ganglia and downstream connections.
Highlights
Huntington’s disease (HD) is an autosomal dominant neurodegenerative disease caused by an expanded CAG repeat on the short arm of chromosome 4 [1]
Among the static parameters analyzed, stride length (Figure 2) was augmented in transgenic rat model of HD (tgHD) rats (P = 0.02), while the base of support did not show any significant difference between groups
Our behavioral study demonstrated that tgHD rats show gait abnormalities in the early symptomatic phase of the disease
Summary
Huntington’s disease (HD) is an autosomal dominant neurodegenerative disease caused by an expanded CAG repeat on the short arm of chromosome 4 [1]. Slight motor abnormalities, like finger tapping, tongue protrusion, and tandem gait, in premanifest HD (gene carriers not yet demonstrating motor symptoms and functional decline), are associated with an early onset of the disease and smaller striatal volumes [4]. Greek word for dance, chorea, is defined as an unpredictable, rapid, involuntary, nonrepetitive movement affecting the face, trunk, and/or limbs [5]. Gait is another aspect of motor function that shows remarkable abnormalities in HD individuals, ranging from lateral or side-to-side deviations and imbalance to difficulties with turning and initiation of gait in some cases. It has been hypothesized that choreic movements cause gait disturbances and loss of balance in HD individuals [9].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
