Vasculitic Peripheral Neuropathy, Differences Between Systemic and Non-Systemic Etiologies: A Case Series and Biopsy Report.

Abstract

Vasculitic peripheral neuropathy (VPN) is caused by vessel inflammation leading to peripheral nerve injury of acute-to-subacute onset. When VPN occurs in the context of systemic disease it is classified as Systemic Vasculitic Neuropathy (SVN) and as Non-Systemic Vasculitic Neuropathy (NSVN) when restricted to the nerves. This study aimed to compare the clinical characteristics, biopsy findings and disease outcome in patients with VPN. Clinical records of adult patients with VPN diagnosed at our institution between June-2002 and June-2019 were retrospectively reviewed. Demographic characteristics, clinical manifestations, nerve conduction studies, nerve biopsies, treatment and clinical evolution were analyzed in all patients with at least 6 months follow-up. Twenty-five patients with VPN were included (SVN, n = 10; NSVN, n = 15). No significant differences in demographic or clinical features were found between groups. The median delay between symptom onset and nerve biopsy was significantly longer in NSVN patients (10 vs 5.5 months, p = 0.009). Erythrocyte sedimentation rate (ESR) values over 20 mm/h were significantly more common in SVN patients (100% vs. 60%, p = 0.024). Nerve biopsies showed active lesions more frequently in treatment-naive patients compared to those who had received at least 2 weeks of corticosteroids (92% vs 38%; p = 0.03), with a higher proportion of definite VPN cases (92 vs 46%; p = 0.04). Although the clinical manifestations are similar, ESR is an important tool to help distinguish between both conditions. Early nerve biopsy in untreated patients increases diagnostic accuracy, avoiding misdiagnosis.