Pooneh Heshmati
The Feinstein Institute for Medical Research, USA
Title: Reduced hippocampal-thalamic fiber tracts in Systemic Lupus Erythematosus
Biography
Biography: Pooneh Heshmati
Abstract
Purpose
SLE patients experience deterioration in cognitive function over time but attribution to disease-related mechanisms is confounded by medication effects, disease flares, hormonal influences and infection. The purpose of this study was to use magnetic resonance diffusion tensor imaging (DTI) to determine whether changes in the anatomical connectivity might begin to account for the cognitive impairment in SLE subjects.
Methods
17 SLE patients with inactive disease and no history of CNS involvement and 14 gender, age-matched healthy control (HC) subjects were imaged using DTI with a 3T MRI scanner (57 slices of 2.5 mm thickness, FOV 240 mm, data acquisition matrix 128 x128 zero filled to 256 x 256, TR 15s). Five b=0 images and 33 diffusion weighted images with b=800 s/mm2 were acquired. The DTI images were processed using FSL routines (FMRIB software library: www.fmrib.ox.ac.uk/fsl), and FA and MD maps were calculated. Tracts were reconstructed based on clusters identified by voxel-wise comparison of FDG PET scans using TrackVis software (http://www.trackvis.org/).
Results
Relative to HC, the SLE group displayed a 28% reduction in hippocampal-thalamic (HT) tract count. The basal ganglia-thalamic tract was preserved in the SLE group (% 8.5 difference), whereas hippocampal-parietal tract number was increased (+30%) relative to HC.
Conclusions
This is the first study to show abnormal HT tracts in SLE subjects. Abnormalities in the HT tract have been associated with impaired learning and memory as well as with increased symptoms in individuals at high risk for schizophrenia.