Abstract
Background The diagnosis of anti-neutrophilic cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) in first episode strokes is more challenging compared with consecutive strokes, especially in patients lacking other clinical features of AAV.
Methods/Results Here, we present the case of a 71-year-old female with positive myeloperoxidase (MPO) ANCA and negative proteinase 3 (PR3) ANCA. Our patient presented with a one-week history of pyramidal weakness in both upper and lower limbs, hyperreflexia and clonus. Brain MRI demonstrated widespread bi-hemispheric cortical and deep white matter acute infarcts. Investigations revealed eosinophilia on full blood examination and positive MPO-ANCA antibody. Consistent with features of stroke secondary to AAV, the deep penetrating vessels were predominantly affected resulting in a multifocal distribution of infarcts in the white matter. MPO-ANCA positive vasculitis diseases are more commonly associated with renal, pulmonary and cutaneous manifestations, however our patient did not have other systemic manifestations of AAV, and her presentation was solely limited to the CNS.
Conclusions This case highlights the challenges of diagnosing primary CNS vasculitis, especially an atypical MPO-ANCA positive disease that fails to have the classical clinical signs and course.