Vasculitic neuropathy: clinical features, diagnostic approach, and neurological outcomes in a single-center cohort

Vasculitic neuropathy (VN) is a diverse group of immune-mediated peripheral neuropathies that result in systemic or non-systemic vasculitic neuropathy. There are limited studies that characterize the neurological outcome of VN patients. We aimed to describe the clinical features, diagnostic workup, and neurological outcomes of VN patients.

We retrospectively reviewed adults with VN evaluated at the Hospital of the University of Pennsylvania between October 2020 and December 2025. Diagnostic classification followed the Peripheral Nerve Society 2010 criteria and the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for systemic vasculitides. Definite vasculitis was defined by biopsy confirmation or fulfillment of formal classification criteria; probable vasculitis was supported by clinical, electrodiagnostic, and serologic features. Neurological impairment was quantified using the Neuropathy Impairment Score (NIS). Improvement was defined a priori as a decrease in NIS of at least 2 points (ΔNIS ≤ - 2). Continuous variables were compared using Welch two-sample t-tests; categorical variables using Fisher exact tests.

Of 85 patients, 66 met inclusion criteria. Non-systemic disease was analyzed as two distinct entities, the NSVN subtype (n = 18, 27.3%) and lumbosacral radiculoplexus neuropathy (LRPN; n = 15, 13 diabetic and 2 non-diabetic), alongside systemic vasculitic neuropathy (n = 33). The most common subtypes were the NSVN subtype (27.3%), ANCA-associated vasculitis (22.7%), and diabetic LRPN (19.7%). Biopsy was performed in 48 patients and demonstrated vasculitis in 41; the remaining patients met criteria for possible vasculitic neuropathy on clinical, electrodiagnostic, and serologic grounds (59 definite, 7 possible overall). Over a median follow-up of 13.5 months (IQR 6.2-31.2), 39 patients (59.1%) improved by ≥ 2 NIS points, 5 (7.6%) were stable, and 22 (33.3%) worsened. Patients who improved had higher baseline NIS-motor subscores (17.3 ± 14.6 vs. 6.7 ± 7.9, p < 0.001) and shorter diagnostic delays (12.3 ± 16.4 vs. 30.3 ± 41.7 months, p = 0.042).

Majority of patients experienced neurological improvement on the NIS. Greater baseline motor impairment and shorter diagnostic delay were associated with improvement. These findings characterize the clinical course of VN in a contemporary tertiary-care setting and provide a benchmark for future multicenter studies.