ACCURACY OF 133-XENON REGIONAL CEREBRAL BLOOD-FLOW AND QUANTITATIVE ELECTROENCEPHALOGRAPHY IN SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective: comparative assessment of sensitivity and specificity of re gional Cerebral Blood Flow (rCBF) by 133-Xenon inhalation and quantita tive Electroencephalography (qEEG) in patients with Neuropsychiatric S ystemic Lupus Erythematosus (NP-SLE). Methods: Sixty-two combined rCBF and qEEG examinations were performed in fifty-two SLE patients. Group A: 27 SLE patients without NP-SLE; group B: 17 patients with florid ( within 1 month) NP-SLE; group C: 12 patients with previous NP-SLE exam ined in the remission phase (four patients of which already considered in group B). The study also included data deriving from two sets of e xaminations in ten patients who were observed twice, in different phas es of the clinical course of NP-SLE. Results: in comparison to healthy controls, rCBF was lower (p < .001) in group B only, whereas qEEG sho wed similar increases of both delta and theta relative powers together with a reduction of alpha relative power in groups A-C. As compared t o group A, sensitivity and specificity in detecting cerebral abnormali ties in group B were 76% and 78% for rCBF, and 59% and 44% for qEEG, r espectively. In the ten patients examined twice, rCBF was consistent w ith clinical course in 90% of cases and qEEG in 60%. Conclusion: total accuracy in detecting cerebral functional abnormalities during florid NP-SLE is better by rCBF than by qEEG. rCBF and, in selected cases, q EEG examinations are reliable markers of NP-SLE.