Functional MRI in NPSLE patients reveals increased parietal and frontal brain activation during a working memory task compared with controls.
OBJECTIVE
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 < or = 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.
Department of Psychology, Auckland District Health Board, Auckland, New Zealand.
B M
BM
Fitzgibbon
S L
SL
Fairhall
I J
IJ
Kirk
M
M
Kalev-Zylinska
K
K
Pui
N
N
Dalbeth
S
S
Keelan
E
E
Robinson
M
M
During
F M
FM
McQueen
D000328:Adult; D001931:Brain Mapping / Q000379:methods; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D020945:Lupus Vasculitis, Central Nervous System / Q000097:blood / Q000503:physiopathology / Q000523:psychology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008569:Memory Disorders / Q000503:physiopathology / Q000523:psychology*; D008570:Memory, Short-Term; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000378:metabolism / Q000503:physiopathology*
D010100:Oxygen