Diffusion tensor imaging findings in the multiple sclerosis patients and their relationships to various aspects of disability

Background: The aim of the study was to assess microstructural changes within strategic brain regions in multiple sclerosis (MS) patients, using diffusion tensor imaging (DTI), with regard to various aspects of disability. Material and methods: The study comprised 50 patients with relapsing-remitting MS (37 women, 13 men, mean age 36.4 yrs) and 27 age- and sex-matched controls. Using DTI, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained within corpus callosum (CC), both thalami (TH) and middle cerebellar peduncles (MCP). Disability was assessed using Expanded Disability Status Scale (EDSS), MS Functional Composite (MSFC), Symbol Digit Modalities Test (SDMT) and Fatigue Severity Scale (FSS). DTI indices were compared between the patients and controls and in the MS group - referred to disability measures. Results: Significant decrease in FA and increase in ADC within CC and both TH were found in MS patients compared to the controls. DTI indices within CC and TH correlated significantly with SDMT score, and within TH and MCP - with MSFC manual dexterity measure. Conclusions: Changes in DTI measures in normal appearing white and grey matter in the MS patients indicate subtle alterations of the tissue integrity. An occult damage to the strategic brain regions may contribute to various aspects of disability due to MS.