Focal Seizures and Posterior Reversible Encephalopathy Syndrome as Presenting Signs of IgA Vasculitis/Henoch-Schoenlein Purpura—An Educative Case and Systematic Review of the Literature

Background: IgA vasculitis/Henoch-Schoenlein purpura (IgAV/HSP) is a systemic small vessel vasculitis of unknown pathogenesis predominantly affecting children. While skin, GI tract, joints, and kidneys are frequently affected and considered, central nervous system (CNS) involvement of this disease is underestimated. Methods: We provide a case report and systematically review the literature on IgAV, collecting data on the spectrum of neurological manifestations. Results: We report on a 7-year-old girl with IgAV who presented with diplopia and afebrile focal seizures, which preceded the onset of purpura. Cranial magnetic resonance imaging was consistent with posterior reversible encephalopathy syndrome (PRES), showing typical focal bilateral parietal swelling and cortical and subcortical high signal intensities on T2-fluid attenuated inversion recovery (FLAIR) images predominantly without diffusion restriction. Cerebrospinal fluid analysis and blood tests excluded systemic inflammation or vasculitis. Interestingly, hypertension was not a hallmark of the developing disease in the initial phase of PRES manifestation. Renal disease and other secondary causes for PRES were also excluded. Supportive- and steroid treatment resulted in restitution ad integrum. Reviewing the literature, we identified 28 other cases of IgAV with CNS involvement. Severe CNS involvement includes seizures, cerebral edema, or hemorrhage, as well as PRES. Thirteen patients fulfilled all diagnostic criteria of PRES. The mean age was 11.2 years (median 8.0, range 5-42 years), with no reported bias toward gender or ethnic background. Treatment regimens varied from watchful waiting to oral and intravenously steroids up to plasmapheresis. Three cases showed permanent CNS impairment. Conclusion: Collectively, our data demonstrate that (I) severe CNS involvement such as PRES is an underappreciated feature of IgAV, (II) CNS symptoms may precede other features of IgAV, (III) PRES can occur in IgAV, and differentiation from CNS vasculitis is challenging, (IV) pathogenesis of PRES in the context of IgAV remains elusive, which hampers treatment decisions. We, therefore, conclude that clinical awareness and the collection of structured data are necessary to elucidate the pathophysiological connection of IgAV and PRES.