RESEARCH - Functional MRI in neuropsychiatric SLE patients reveals increased parietal and frontal brain activation

[Guest guest]

Rheumatology Advance Access originally published online on November 24, 2007

Functional MRI in NPSLE patients reveals increased parietal and frontal

brain activation during a working memory task compared with controls

B. M. Fitzgibbon1, S. L. Fairhall1, I. J. Kirk1, M. Kalev-Zylinska2, K.

Pui4, N. Dalbeth2, S. Keelan2, E. 3, M. During2 and F. M. McQueen2

Departments of 1Psychology, 2Molecular Medicine and Pathology,

3Biostatistics, University of Auckland and 4Rheumatology, Auckland District

Health Board, Auckland, New Zealand.

Abstract

Objectives. Anatomical MRI brain scans may not reflect neurological

dysfunction in patients with NPSLE. We used blood-oxygen-level-dependent

functional MRI (BOLD-fMRI) to investigate working memory function in NPSLE

patients.

Methods. Twenty-seven females took part: nine NPSLE patients (mean age 40

yrs; SLEDAI 10.9); nine RA patients and nine healthy controls. Subjects were

tested using the n-back paradigm for working memory, where patients indicate

when a stimulus matches one presented n trials previously. Functional scans

used 3 mm slices x 30, repetition time 2570 ms, echo time 50 ms. Echo planar

images were superimposed onto T1w anatomical images (Siemens 1.5 T). Data

analysis used Brain Voyager QX Version 1.7.

Results. During the memory task, there was activation in areas serving

working memory, executive function and attention in all groups. Nine regions

of interest were selected for activation during working memory (N-back task

vs fixation, P 0.005). In six out of nine regions, there was greater

activation in the NPSLE group. This reached significance in three regions:

the posterior inferior parietal lobules of both hemispheres [brodmann area

(BA) 7] separately and combined (P = 0.014, 0.016 and 0.004, respectively),

and the supplementary motor area (mid-line frontal lobe)(BA32/6; P = 0.032).

Conclusions. NPSLE patients showed greater frontoparietal activation than

the other groups during the memory task, suggesting a greater need to

recruit extra cortical pathways, possibly to supplement impaired function of

standard pathways.

http://rheumatology.oxfordjournals.org/cgi/content/abstract/47/1/50

Not an MD