Longitudinal evaluation of diffusion tensor imaging and cognition in systemic lupus erythematosus

Abstract

Objective This pilot study aimed to examine longitudinal changes in brain structure and function in patients with systemic lupus erythematosus (SLE) using diffusion tensor imaging (DTI) and neuropsychological testing. Methods Fifteen female SLE patients with no history of major neuropsychiatric (NP) manifestations had brain magnetic resonance imaging (MRI) with DTI at baseline and approximately 1.5 years later. At the same time points, a standardized battery of cognitive tests yielding a global cognitive impairment index (CII) was administered. At baseline, the SLE patients had mean age of 34.0 years (SD = 11.4), mean education of 14.9 years (SD = 2.1), and mean disease duration of 121.5 months (SD = 106.5). The MRI images were acquired with a 3T GE MRI scanner. A DTI sequence with 33 diffusion directions and b-value of 800 s/mm was used. Image acquisition time was about 10 minutes. Results No significant change in cognitive dysfunction (from the CII) was detected. Clinically evaluated MRI scans remained essentially unchanged, with 62% considered normal at both times, and the remainder showing white matter (WM) hyperintensities that remained stable or resolved. DTI showed decreased fractional anisotropy (FA) and increased mean diffusivity (MD) in bilateral cerebral WM and gray matter (GM) with no major change in NP status, medical symptoms, or medications over time. Lower FA was found in the following regions: left and right cerebral WM, and in GM areas including the parahippocampal gyrus, thalamus, precentral gyrus, postcentral gyrus, angular gyrus, parietal lobe, and cerebellum. Greater MD was found in the following regions: left and right cerebral WM, frontal cortex, left cerebral cortex, and the putamen. Conclusions This is the first longitudinal study of DTI and cognition in SLE, and results disclosed changes in both WM and GM without cognitive decline over an 18-month period. DTI abnormalities in our participants were not associated with emergent NP activity, medical decline, or medication changes, and the microstructural changes developed in the absence of macrostructural abnormalities on standard MRI. Microstructural changes may relate to ongoing inflammation, and the stability of cognitive function may be explained by medical treatment, the variability of NP progression in SLE, or the impact of cognitive reserve.

Cognitive Dysfunction in Systemic Lupus Erythematosus: Immunopathology, Clinical Manifestations, Neuroimaging and Management

“…Low fractional anisotropy (FA) indicates damaged white matter, which may be due to decreased axonal density, number, diameter or myelination [29]. Decreased FA in the external capsule has been reported in SLE patients with CD [106][107][108]. MTI quantifies the exchange of magnetization between macromolecule-bound proteins in myelin and water protons in biological tissues by generation of a magnetization transfer ratio (MTR).…”

Cognitive dysfunction in autoimmune rheumatic diseases

“…Thus, there remains a need for an objective and non-invasive means to establish neurological dysfunction in SLE patients both for investigative purposes, as well as for clinical diagnosis and surveillance. There is evidence to suggest that SLE patients, with and without overt NPSLE, have aberrations in their white matter microstructures as seen by diffusion tensor imaging (DTI) [36]. Functional MRI studies have shown increased functional connectivity in core resting-state networks in SLE patients that correlate with reduced cognitive performance compared with healthy controls [37].…”

Altered Temporal Dynamics of Brain Activity in Multiple-Frequency Bands in Non-Neuropsychiatric Systemic Lupus Erythematosus Patients with Inactive Disease

“… 35 , 63 In diffusion tensor imaging (DTI) studies of SLE patients, decreased fractional anisotropy (FA) in both PreCG and PoCG was found. 64 Furthermore, we found the significantly negative correlations between glucocorticoid dose and dReHo values in PreCG and left PoCG. These findings suggested the low-sustained dose of glucocorticoid may also contribute to the compensatory mechanism of the left PoCG and right PreCG in non-NPSLE patients.…”