SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY SCANNING IN CHILDHOOD SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective, To determine the role of central nervous system (CNS) perfu sion scanning in detecting CNS disease in childhood onset systemic lup us erythematosus (SLE) and serial single photon emission computed tomo graphy (SPECT) scans in monitoring CNS disease activity in childhood. Methods, The charts of 108 patients with a confirmed or suspected diag nosis of SLE during the period February 1987 to June 1992 were reviewe d. Twenty patients with a diagnosis of CNS SLE and 10 patients without CNS involvement had at least one SPECT scan. Patients were divided in to (a) focal CNS SLE, when there were clinical manifestations that cou ld be attributed to localized lesions of the CNS (6 patients); and (b) diffuse CNS SLE, when there was a global defect in CNS function inclu ding organic brain syndrome, psychosis, and depression (14 patients). If a patient had both diffuse and focal CNS disease that patient was d esignated as having diffuse disease. Forty-three patients with a diagn osis other than SLE comprised our non-SLE control group. Results, SPEC T scans were performed in 20 patients with acute CNS involvement. In p atients with acute diffuse CNS disease, diffuse patchy areas of hypope rfusion were seen in 86% of patients at presentation of the CNS event. In the focal CNS disease subgroup, 33% of patients had an abnormal sc an at CNS presentation. In these patients focal rather than diffuse ab normalities were seen. Eight patients with diffuse CNS SLE had at leas t one followup study at intervals ranging from 1 month to 3 years afte r initial scan. In 50% of these patients with diffuse CNS involvement, improvement in their abnormal scan correlated with clinical improveme nt, while in the other 50% clinical improvement was not associated wit h SPECT scan improvement. The most common abnormal SPECT scan pattern in patients with CNS SLE was one of widespread multiple small areas of decreased uptake at multiple sites, suggestive of generalized patchy hypoperfusion. Although SPECT scans were sensitive to the presence of CNS disease, the diffuse hypoperfusion was not specific for clinically detectable CNS involvement. In patients with SLE, a diffusely abnorma l scan had a specificity of 69% and a likelihood ratio of 2.2 to corre ctly detect overt diffuse CNS disease. Conclusion. Although we found t hat SPECT scanning was a highly sensitive method, it was not a specifi c method in correctly diagnosing diffuse CNS SLE in children. However, the presence of an abnormal SPECT scan in SLE patients with no histor y of overt CNS SLE may suggest that subclinical CNS disease may be mor e common in children than previously suggested.