The Correlation Between Cognitive Impairment And The Volume Change Of The Subcortical Nuclei In Spinocerebellar Ataxia Patients

Background:Spinocerebellar ataxia (SCA) is a most common type of hereditary ataxia. The main pathological changes of this disease occurs in spinal cord, cerebellum, and brainstem clinical manifestation of ataxia,movement disorders of body and trunk, dysarthria, and oculomotor disorders. With more and more attentions to the SCA related cognitive impairment, imaging studies found the obvious atrophy at special cortical area in SCA patients comparing to normal population. The aim of this study is to investigate the relationship between the volume change of the subcortical nuclei and the cognitive impairment in SCA patients.Methods:We recruited 11 patients with spinocerebellar ataxia (including 7 spinocerebellar ataxia type 3 (SCA3) and 4 spinocerebellar ataxia type 2 (SCA2)) and 13 controls from the Nanjing Drum Tower Hospital affiliated to Nanjing University Medical School during 2010to 2013. All the patients were given assessment of cognitive function and high-resolution T1-weighted images. We used Freesurfer software to calculate the volume of subcortical nuclei. We recorded the basic demographic information of subjects and followed them up for 2year. Then we gave all patients another MOCA and divided them into two group:1) cognitive impairment (CI) group,2) non cognitive impairment (NCI) group.Results:The result of MRI at the start of our study showed that the subcortical nuclei of SCA was atrophic than that of control, especially in the cerebellum white matter, cerebellum cortex, brain stem, pallidum, hippocampus, and Ventral diencephalon (Ventral-dc). Consequence of the follow-up proved SCA group had obvious cognitive impairment than normal group in general, including visual space, executive function, attention and delayed recall. Although the volume of subcortical nuclei in CI and NCI had no significant difference, the subregion of hippocampal such as CA2-3, CA4-DG, Presubiculum were significantly atrophic in CI.Conclusion:Some SCA patients does have cognitive impairment and widespread subcortical atrophy. And before the clinical manifestation of cognitive impairment, the atrophy of volume in nuclei and hippocampus-subareas can already be detected. Therefore, we might be able to forecast the cognitive impairment of SCA patients on the basis of the volume of hippocampal subarea.