Primary CNS angiitis - an uncommon vasculitis affecting brain, spinal cord, or leptomeninges, typically B/L, but here are 48 pts w/ unilateral PACNS. Dx is made by imaging, wall imaging (VWI), perfusion, spectroscopy. Histology shows small-to med vessel lymphocytic vasculitis https://t.co/xtD7wBT1J2