Gait impairment precedes clinical symptoms in spinocerebellar ataxia type 6

Background Spinocerebellar ataxia type 6 (SCA6) is an inherited ataxia with no established treatment. Gait ataxia is a prominent feature causing substantial disability. Understanding the evolution of the gait disturbance is a key step in developing treatment strategies. Methods We studied 9 gait variables in 24 SCA6 (6 presymptomatic; 18 symptomatic) and 24 controls and correlated gait with clinical severity (presymptomatic and symptomatic). Results Discrete gait characteristics precede symptoms in SCA6 with significantly increased variability of step width and step time, whereas a more global gait deficit was evident in symptomatic individuals. Gait characteristics discriminated between presymptomatic and symptomatic individuals and were selectively associated with disease severity. Conclusions This is the largest study to include a detailed characterization of gait in SCA6, including presymptomatic subjects, allowing changes across the disease spectrum to be compared. Selective gait disturbance is already present in SCA6 before clinical symptoms appear and gait characteristics are also sensitive to disease progression. Early gait disturbance likely reflects primary pathology distinct from secondary changes. These findings open the opportunity for early evaluation and sensitive measures of therapeutic efficacy using instrumented gait analysis which may have broader relevance for all degenerative ataxias

Ambulatory activity in incident Parkinson’s: More than meets the eye?

Physical activity is important for people with Parkinson’s disease (PD) to improve disease-specific impairment and ameliorate secondary consequences related to deconditioning. Activity may also have a neuroprotective role if instigated early. Ambulatory activity has not been examined in incident PD. Eighty-nine newly diagnosed PD cases [mean (SD) age 67.3 (9.9) years] and 97 controls [mean (SD) 69.2 (7.7) years] wore an activity monitor (activPAL™) for 7 days. Volume, pattern and variability outcomes were compared. Accumulation of activity (α) was classified as short ( 2 min) bouts of walking. Associations between sustained walking (> 2 min) and motor, cognitive and affective characteristics were identified. Activity outcomes were considered with respect to global health recommendations. Total steps (volume), accumulation of bout length (α), and variability (S2w) outcomes were significantly different (all P 2 min) of walking compared with controls, due to performing fewer long bouts, rather than a reduction in time spent in walking per bout. For PD and controls there were weak but significant correlations for a range of characteristics and sustained walking. Fewer people with PD achieved the recommended 30 min of walking per day comprised of bouts > 10 min (P = 0.02) and bouts > 2 min (P < 0.001). People with PD were significantly less active than controls, with an inability to sustain levels of walking, and with differences apparent very early on in the disease process. A focus on increasing general ambulatory activity and exercise from the outset is recommended