Childhood central nervous system lupus; longitudinal assessment using single photon emission computed tomography

Neuropsychiatric manifestations in children with systemic lupus erythematosus (SLE) occur in 30-60% of patients during the course of disease. Unlike other manifestations of childhood SLE, few laboratory studies and imaging modalities aid in the diagnosis of central nervous system (CNS) lupus. We and others have reported the usefulness of single photon emission computed tomography (SPECT) in the initial assessment of cerebral blood flow in children with active CNS involvement. We extend these observations to longterm followup using the SPECT scan to determine its usefulness in the subsequent course of CNS lupus in children.

Eleven children who developed CNS disease and fulfilled the classification criteria for SLE were included in an open pilot study. The patients were followed up to 3.5 years and presented with CNS manifestations: encephalopathy with or without grand mal seizures (N = 4), focal seizures with depression or hallucinations (N = 3), optic neuritis with transverse myelitis (N = 2), and psychosis with audiovisual hallucinations (N = 2). Initially, all children had lumbar puncture, SPECT, and serologic testing; 9 children had electroencephalogram (EEG), 7 had computerized tomography (CT), and 10 had magnetic resonance imaging (MRI). SPECT was repeated in 7 patients 1-4 months after the initial CNS event and thereafter in 10 patients annually.

At the time of the initial CNS event, 9/11 children (82%) had normal results for lumbar puncture, 7/9 (78%) for EEG, 5/7 (71%) for CT, and 6/10 (60%) for MRI. All patients (100%) had diffusely abnormal SPECT: In addition, 5/11 (45%) tested positive for IgG antibodies to cardiolipin and dsDNA, and 4/11 (36%) had antibodies to Sm. In 5/7 children whose SPECT was repeated 1 to 4 months after the CNS event, additional perfusion defects were documented compared with initial SPECT: During the subsequent 1-3.5 years and concomitant with treatment, CNS manifestations resolved clinically, but none of the SPECT scans became normal. Perfusion defects improved over time in 4 patients and worsened in 6.

SPECT scan remains a sensitive tool during initial CNS events in children with CNS lupus documenting the presence of damage during short term followup of 1-4 months. However, during longterm followup abnormalities documented by SPECT no longer correlate with the patient's clinical course, limiting the usefulness of SPECT as a clinical tool in children who recover from CNS disease.