Our kinetics studies document an early cognitive defect in WT mice, which was absent in ST2-/- mice, 5 days post-PbA infection, at a time when there are no ECM-related neurological symptoms like ataxia or coma, no brain blood flow or BBB defect, before sequestration of inflammatory and CD8+ pathogenic T cells. Here, CD8A is linked to cerebellar ataxia.