Damage to the cerebellum produces characteristic deficits in movement coordination, known
as "ataxia." Reaching movements become curved, tremulous, and over- or undershoot
targets, thus affecting nearly all activities of daily living. Sitting and standing
balance becomes unsteady, and walking has a characteristic 'drunken' appearance with
lateral veering and a widening of the base of support. People with many types of
neurological diseases (e.g. autosomal dominant ataxias (e.g. SCAs), multiple sclerosis,
cerebral palsy, stroke, Freidreich's ataxia) often have disabling ataxia.
In past work the investigators have shown that many individuals with ataxia from
cerebellar disease can learn simple visuomotor tasks using reinforcement learning
paradigms. The investigators do not know if individuals with ataxia from cerebellar
disease can improve more complex motor patterns. In general, there are few rehabilitation
studies on ataxia, with most focusing on balance and walking. Yet, arm ataxia is a
significant problem that affects most all activities of daily living (e.g. eating,
cooking, bathing, dressing, working). Many studies have assessed reaching ataxia on
single days in order to try to better understand the fundamental basis for ataxic arm
movements. Based on previous literary searches, there are only a couple of small studies
that have tested whether training over weeks can mitigate arm ataxia. Each of these was a
case series of either 3 or 4 people, and all patients had ataxia from lesions that
included structures outside of the cerebellum. Both showed some positive effects but
responses varied across patients. This work that the investigators propose will look at
the affects of a longer training regimen of upper limb reaching in people with cerebellar
ataxia.
The investigators will study cerebellar patients that have shown the ability to learn
from previous work. Subjects with cerebellar ataxia will be randomized into two groups to
receive either reinforcement training or standard practice training over a 12 week
period. Subjects will train for 45 minutes a day, 3 times per week for two weeks for each
type of training, with a two week 'rest' period in between. After training, subjects will
be asked to return for two visits to test for retention. On each training day,
reinforcement training (or standard practice) will be done using an Oculus Rift and Touch
3D headset. Training encompasses reaching to a 3D target with either online visual
feedback or binary feedback 400 times. Motion tracking sensors will be placed on the
shoulder, elbow, wrist, and finger, in order to track movement data in real time. These
studies will provide important new information about upper limb long term training with
visual feedback in individuals with Cerebellar Ataxia