Fatigue in patients with lupus is not associated with disturbances in cerebral blood flow as detected by SPECT.

OBJECTIVES

Fatigue is a common complaint in patients with systemic lupus erythematosus (SLE). We investigated whether focal or general disturbances of cerebral blood flow (CBF), as assessed by SPECT, were associated with the presence of fatigue in an unselected group of SLE patients.

METHODS

Fifty-six patients were included. Mean age was 47.5 years (+/-12.7), mean disease duration 14.7 years (+/-8.9), and disease activity measured by SLE disease activity index (SLEDAI) was 5.7 (+/-5.4). Fatigue was assessed by the Fatigue Severity Scale (FSS) and CBF by Tc-99m-hexamethyl propylamine oxime (HMPAO)-SPECT. The images were read and processed quantitatively by a computer program using the primary visual cortex as reference region and > 15% CBF deviation as definition of abnormality.

RESULTS

The mean FSS score was 4.6 (+/-1.8). SPECT revealed focal CBF disturbances in 17 patients (30.4 %). Generalized symmetrical CBF reductions were present in 32 patients (57.1 %). There were no significant associations between CBF disturbances in any region of the brain and the degree of fatigue.

CONCLUSIONS

Fatigue in SLE patients is not related to focal or general CBF disturbances. Therefore, factors that do not influence blood flow seem responsible for the fatigue phenomenon.