Corticobulbar Tract Involvement in Neuropsychiatric Systemic Lupus Erythematosus: A Case Report

A 36-year-old woman, diagnosed with systemic lupus erythematosus (SLE), showed bulbar symptoms including impaired memory, slurred speech and swallowing difficulty 7 days before admission. Magnetic resonance imaging (MRI) showed symmetric confluent hyperintensities in the bilateral cerebral white matter on T2 weighted imaging (T2-WI), extended into the genu of the internal capsule and the crus cerebri of the midbrain. MR spectroscopy showed increased choline and decreased N-acetyl aspartate (NAA) peak and positron emission computed tomography (PET CT) showed decreased fluorodeoxyglucose (FDG) uptake on the lateral portion of the frontal lobe, suggesting demyelination of the white matter. The value of apparent diffusion coefficient, fractional anisotropy, tensor linear, tensor planar and relative anisotropy of the corticobulbar tract (CBT) were lower than those of the corticospinal tract. This is the first case report of CBT involvement in a patient with neuropsychiatric SLE (NPSLE) as far as we know. The findings of T2-WI and diffusion tensor imaging (DTI) showed precise anatomical location of neuronal damage of CBT. In addition, magnetic resonance spectroscopy (MRS), PET-CT and parameters of DTI supported the explanations of the inflammatory process and metabolic change of the white matter caused by NPSLE.