Proprioceptive training for patients with degenerative cerebellar ataxia.

• Applicant: Professorin Dr. Dagmar Timmann-Braun
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 256047747

Cerebellar degenerative ataxias are slowly progressive disorders, which lead to increasing motor impairments. The development of a sound, research-based behavioral therapy seems to be the most promising avenue to improve ataxia until pharmacological or genetic treatments may become available in the future. Although there is first evidence that physiotherapy improves motor performance in degenerative ataxias, there is lack of specific training programs, which take knowledge about the physiology and pathophysiology of the cerebellum in account. For example, despite the fact that the cerebellum receives massive proprioceptive afferents, no existing physical therapy stresses the improvement of proprioceptive function in cerebellar ataxia. Likewise, the linking of training with largely intact explicit memory mechanisms has not been researched systematically. It is thus the main goal of this project to provide a proof of principle that motor function of patients with a degenerative ataxias can improve through a regime of pure proprioceptive training (i.e., without visual feedback), and that exploitation of intact explicit memory mechanisms leads to further improvement of motor function. Specifically, we propose that proprioceptive training leads to improved proprioceptive sensitivity and/or acuity of passive and active motion sense. We will test the hypothesis that proprioceptive training yields better motor performance outcomes than conventional implicit visuomotor learning in patients with degenerative ataxia. In addition, we test the hypothesis that coupling explicit, strategic learning mechanisms with implicit motor learning yields better outcomes than implicit motor learning alone in patients with cerebellar degenerative ataxia. To operationalize this aim, explicit verbal information about joint position errors and the required adjustments to improve motor performance will be provided.Neuroimaging will be used to provide information on the neural correlate of such training. We test the hypothesis that proprioceptive training leads to increased gray matter density of the cerebellar cortex, increased fractional anisotropy (FA) of superior cerebellar peduncles, and increased activity of the cerebellar resting state network. Furthermore, we test that explicit strategic learning leads to increased gray matter density of the frontal cortex (dorsolateral prefrontal cortex, rostral supplementary motor area, anterior cingulate cortex) and increased FA of projection fibers of the anterior limb of the internal capsule. In addition, we predict that explicit strategic learning is related to increased gray matter density of basal ganglia and leads to increased activity in fronto-basal-ganglia networks. The project is performed jointly between three groups with complementary expertise in the study of motor disorders: human cerebellar lesion studies (Timmann-Braun), clinical movement science (Konczak) and brain imaging (van Eimeren, Granert).

• DFG Programme: Research Grants
• International Connection: USA
• Participating Persons: Oliver Granert; Professor Dr. Jürgen Konczak