Early and delayed Tc-99m ECD brain SPECT in SLE patients with CNS involvement

We compared early and delayed Tc-99m ECD SPECT scans in 32 SLE patients (Gr oup I,definite neuropsychiatric disorders; Group 2, minor neurologic sympto ms or normal) with those of normal controls by visual inspection and semi-q uantitative evaluation. With visual interpretation, 13 out of 14 patients i n Group 1 (93%) and 7 out of 18 patients in Group 2 (39%) had diffuse uneve n decrease in early scans. Seven patients in Group 2 (39%) who had normal e arly scans demonstrated focal decrease in the medial frontal lobe in delaye d scans. With cerebral region to cerebellar ratios, in early scans, the med ial frontal lobe in Group 1 and Group 2 was significantly lower than in nor mal controls, and lateral frontal lobe and occipital lobes in Group I were significantly lower than in normal controls. Nevertheless, in delayed scans , every cortical region except for the parietal lobe in Groups 1 and 2 was significantly lower than in normal controls. The retention rates in all reg ions in SLE patients were significantly lower than in normal controls. No c ase showed SPECT improvement on follow-up studies in either group in spite of clinical improvement. Delayed Tc-99m ECD brain SPECT of high sensitivity might be useful in detecting CNS involvement. Although the SPECT findings did not correlate with the neuropsychiatric symptoms, early and delayed Tc- 99m ECD SPECT seems to provide useful objective diagnostic information in S LE patients.