Objective: To test the sensitivity of single photon emission computerized tomography (SPECT) in detecting brain abnormalities in cases of definite active neuropsychiatric systemic lupus erythematosus (NPSLE) in a blinded, prospective pilot study.
Methods: Fourteen patients fulfilling at least 4 of the American College of Rheumatology criteria for the classification of SLE plus positive serology manifested by either elevated DNA binding or decreased serum complement and a recent neuropsychiatric event were evaluated with cerebral SPECT using hexa-methyl-propylene-amine-oxime labeled 99Tc. Secondary causes such as infection, uremia, hypertension, drugs, and metabolic abnormalities were excluded. Patients underwent brain scan and electroencephalogram (EEG) for comparison. When clinically indicated, CT scan, magnetic resonance imaging, angiography, and lumbar puncture were performed.
Results: SPECT scan abnormalities were noted in 12/14 patients and brain scan was abnormal in 12/14 patients. SPECT and brain scan were in accordance in 12/14 patients (11 patients both positive and 1 both negative) and the combination of SPECT and brain scan yielded 13/14 positive results. In the 3 patients with headache, SPECT scan was negative in 2/3, despite positive EEG and one with a positive brain scan. The positive SPECT in the patient with headache showed an old cerebrovascular accident (CVA), which was confirmed by CT scan. The most consistent CT finding was cortical atrophy; however, SPECT identified a lesion in the occipital cortex in a patient with seizure, and a lesion in the basal ganglia in a patient with ataxia.
Conclusion: In clinically and serologically active NPSLE, SPECT is a sensitive diagnostic tool. When further stratifying NPSLE into focal (seizure, ataxia, CVA) and diffuse (headache, organic brain syndrome, psychosis), SPECT appeared to be sensitive for focal disease and for most diffuse manifestations, with the exception of headache. The high sensitivity of SPECT in patients with true, positive NPSLE merits further controlled studies in unselected patients with SLE.