What is the role of diffusion tensor imaging (DTI) in detecting subclinical pyramidal tract dysfunction in Behçet's and neuro-Behçet's cases?

The aim of this study is to investigate the pyramidal tract integrity with DTI in Behçet's and neuro-Behçet's cases. We performed this technique in two subgroups of neuro-Behçet's patients (parenchymal and vascular), and Behçet's cases without neurological involvement and control group. Totally, 28 patients were investigated. The control group was composed of 14 healthy people. Cranial MR and DTI were performed in three patient groups and the control group. At DTI, circular regions of interest (ROI) were symmetrically drawn on axial slices on the left and right sides along the pyramidal tract pathway at two levels: middle one third of the cerebral peduncle and posterior limb of the internal capsule. Fractional anisotropy (FA) values for each ROI were obtained by averaging all voxels within the ROI. Calculated FA values on both sides (left and right) of the posterior limb of the internal capsule and cerebral peduncle are significantly lower in all three patient groups when compared to the control group. But there is no any difference of FA values in the selected brain regions of three patient groups. FA values on the posterior limb of the internal capsule and cerebral peduncle do not show a statistically significant difference in parenchymal neuro-Behçet's cases. Our study demonstrates that DTI can detect subclinical pyramidal tract dysfunction in neuro-Behçet's and Behçet's patients. Detection of subclinical nervous system involvement is crucial for morbidity in Behçet's disease. For this reason, studies based on DTI, which include a large number of patients and explore different brain regions, are needed to guide clinicians.