In reading this study on APS induced mice, the researchers made this blanket statement.
"Many patients develop neurological symptoms in the absence of ischemia but the underlying mechanisms leading to these manifestations are not yet identified...... In conclusion, our results are the first to indicate a role for the dendrites and in particular the dendritic spines in the pathogenesis of aPL-mediated central nervous system dysfunction in eAPS. The autoimmune-induced neurodegeneration in the absence of ischemia could also be a possible contributing factor to the central nervous system dysfunction in APS patients."
Therefore, for those with APS who have neurologic symptoms without stroke, there is a reason. Every year they get closer to the why.