Abstract T P411: Correlation of Neurocognitive Function and Brain Lesion Load on Magnetic Resonance Imaging in Patients with Systemic Lupus Erythematosus

Abstract

Background: Neurocognitive dysfunction and brain injury on MRI are common in patients with systemic lupus erythematosus (SLE) and are associated with increased morbidity and mortality. However, brain MRI is expensive, non-specific, and does not necessarily predict neurocognitive dysfunction. In contrast, neurocognitive assessment is a clinical tool that is easily available, inexpensive, safe, and may better select patients who require an MRI or other cerebrovascular imaging. Methods: 76 patients with SLE [71 women, age 36±12 years] and 26 age-and-gender matched healthy subjects [22 women, age 34±11 years] underwent neurocognitive testing for assessment of global neurocognitive function, attention, memory, processing speed, executive function, and motor function (expressed as z-scores). All 102 subjects underwent brain MRI. T1 weighted, fluid attenuated inversion recovery, and diffusion weighted images were obtained. Whole brain and hemispheric lesion load in cm 3 were determined using a semi-automated method. Results: All assessments of neurocognitive function were significantly worse in SLE patients than in controls, including global cognitive function (-1.82±1.90 versus -0.07±0.52,), attention (-1.80±2. versus -0.06±0.82,), memory (-1.23±1.15 versus -0.056±0.81 ), processing speed (-1.38 ±1.63 versus -0.06±0.93 ), executive function (-2.39±2.96 versus -0.10±0.79,) and motor function (-3.14±5.90 versus -0.06±0.63) (all p≤0.003). Also, white matter brain lesion load of the whole brain, left hemisphere, and right hemisphere were greater in SLE patients than in controls (1.10±2.65 versus 0.10±0.28 cm 3 , 0.41±0.98 versus 0.04±0.13 cm 3 and 0.68±1.97 versus 0.057±0.16 cm 3 , respectively, all p≤0.02]. Neurocognitive scores in each domain were significantly negatively correlated with brain lesion load of the whole brain, left and right hemispheres (r = 0.33 - 0.46, all p≤0.02, Pearson Correlation Coefficients ) . Conclusions: In SLE patients each neurocognitive domain score correlates negatively with brain lesion on MRI. These findings suggest that neurocognitive testing may be an effective initial clinical tool to assess for ischemic brain injury in SLE patients.