Microscopic Polyangiitis With Selective Involvement of Central and Peripheral Nervous System: A Case Report

CNS limited ANCA-associated vasculitis presenting as an isolated intraparenchymal mass

The authors report a 34-year-old male with antineutrophil cytoplasmic autoantibody (ANCA) associated vasculitis (AAV) which only involved the central nervous system and presented with an isolated mass in the left parietal lobe. Constitutional symptoms were lacking and the only symptom was progressive right-sided hemiparesis. Pathology suggested necrotizing vasculitis without eosinophils and granulomas. Cytoplasmic ANCA was elevated to 103.9 IU/ml (>5 times the upper limit) in serum. He obtained a regression following treatment of cyclophosphamide and steroids. Prompt diagnosis of AAV is essential since early and aggressive initiation of immunosuppressive therapy can avoid further neurological sequelae.

Clinical Manifestations, Pathogenesis, Diagnosis and Treatment of Peripheral Neuropathies in Connective Tissue Diseases: More Diverse and Frequent in Different Subtypes than Expected

Purpose of review: To discuss and summarize recent findings in peripheral neuropathy (PN) related to connective tissue diseases (CTD) including its prevalence, clinical manifestations, pathogenesis, diagnosis and treatment. Recent findings: Although PN is a common complication in CTD and has been well studied, recent research has shown that PN is more diverse and frequent in different subtypes of CTD than was expected. The incidence of PN in Sjögren’s syndrome and rheumatoid arthritis (RA) varies according to different disease subtypes, and the pathogenesis of neuropathic pain in different subtypes of eosinophilic granulomatosis with polyangiitis (EGPA) may also differ. Neurogenic inflammation, autoantibody-mediated changes, ischemia of the vascular wall and metabolic mechanisms have been shown to contribute to the pathogenesis of PN in CTD. Moreover, allergic inflammation has been recently identified as a possible new mechanism producing peripheral neuropathic pain associated with MPO-ANCA negative EGPA patients. Glucocorticoids are routinely used to relieve pain caused by PN. However, these steroids may cause hyperalgesia, exacerbate neuropathic pain, and activate the early phase of pain induction and produce hyperalgesia. Recently, neuroactive steroids, such as progesterone, tetrahydroprogesterone and testosterone, have been shown to exert protective effects for several PN symptoms, and in particular neuropathic pain. Neuroactive steroids will be an interesting topic for future research into PN in CTD. Summary: It is essential for the diagnosis and treatment of PN in CTD to be updated. Timely diagnosis, appropriate treatments, and multidisciplinary care are essential to minimize morbidity and decrease the risk of permanent neurologic deficits. Further studies are needed to guide diagnosis and treatment.