[Factor analysis of brain structure reorganization in patient with multiple sclerosis (based on pet data)]

The goal of present study was to investigate the functional reorganization of brain structures in patients with multiple sclerosis (MS). The patterns of distribution of relative estimations of local cerebral metabolic rate of glucose (ICMRglu) in regions of interest (ROIs), corresponding to anatomo-functional brain areas are obtained in groups of healthy volunteers (n=31 subjects) and patients with relapsing-remitting and progressive types of MS (n=59 and 39 accordingly). The analysis of factor structure of the obtained patterns allowed to make a conclusion about the existence of a common features with the factor structure of the distribution of another functional parameter--a regional cerebral blood flow (rCBF). This indicates that both factor solutions mainly reflect the functional organization of a brain. The differences revealed in factor structures of ICMRglu distribution in groups of patients with various types of MS and healthy volunteers allowed to assume that even at early stages of the disease despite the close anatomic and functional connectivity that normally exists between basal ganglia, MS patients have a functional dissociation of these structures. The bipolarity of revealed factors probably reflects the different directionality of the processes: relative decrease of functional activity in the areas which are directly responsible for performance of broken functions, caused by the deafferentation of the specified areas and its compensatory relative increase in functionally connected zones.