Abstract Details

Title Compensatory Shifting in a Functional Network within the Ocular Cerebellum Based on Severity of Disease in SCA6

Topic Behavioral Neurology

Presentation(s) P06 - (-)

Poster/Presentation
Number 061

Objective

Background BACKGROUND: Spinocerebellar ataxia type 6 (SCA6) is a pure cerebellar ataxia characterized primarily by cerebellar atrophy and striking loss of Purkinje cells with preservation of other brain regions. Interestingly, in pre-symptomatic cases, visuo-motor deficits have been shown to reflect initial stages of vermal degeneration.

Design/Methods DESIGN/METHODS: Fourteen SCA6 research volunteers and 20 aged-matched controls participated in the study. The clinical ataxia severity was estimated by means of a validated ataxia rating scale (SARAII) performed the same day of the imaging study. Imaging: Acquisition was performed on a 3T Philips scanner including a high-resolution T1-weighted and functional MRI during a passive smooth-pursuit task without vestibular involvement. Analysis of results included the identification of cerebellar networks via structural equation models.

Results RESULTS: The visual stimulation produced widespread activation in cerebral cortex of SCA patients and controls, but notable differences were noted in the cerebellum. Whereas in controls and pre-symptomatic SCA6 cases the activation was limited to vermis and intermediate cerebellum, concomitant to the development of disease, the activation in vermis was replaced by activation in lateral cerebellum. Network analysis showed that the origin of the unusual lateral cerebellar activation was produced by a distributed cortical network including both, frontal and sensory cortices (parietal and occipital). Of special interest were the networks associated with pre-symptomatic cases where, prior to the apparition of lateral cerebellar activation, there was a reorganization of cortico-cortical connectivity increasing descending influences over the intermediate cerebellum.

Conclusions CONCLUSIONS: Our results highlight early functional changes in cerebellar connectivity that evolves throughout the evolution of the illness perhaps lengthening the viability of the cerebellum. These results can help to design development therapeutic interventions so much needed against this devastating illness.

Authors/Disclosures
Ana Solodkin, PhD ("University of California, Irvine") PRESENTER	No disclosure on file
Inez Falcon, PhD (UC Irvine)	No disclosure on file
	No disclosure on file
Christopher Gomez, MD, PhD (University of Chicago)	Dr. Gomez has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Biogen. The institution of Dr. Gomez has received research support from Nih.
Giancarlo Comi, MD (University Vita-Salute)	Dr. Comi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Janssen. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Bristol Myers Squibb. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Janssen. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bristol Myers Squibb. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Novartis. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Aspen Healthcare. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Sanofi. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Sanofi. Dr. Comi has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Rewind.

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