Nonsystemic Vasculitic Neuropathy-A Brazilian Case Series.

BACKGROUND AND AIMS: Vasculitides are a heterogeneous group of immune-mediated inflammatory disorders that compromise the vascuar wall, leading to luminal narrowing and tissue ischemia. When inflammation selectively affects the vasa nervorum without systemic involvement, it results in nonsystemic vasculitic neuropathy (NSVN), an underrecognized condition. NSVN presents diagnostic challenges due to its variable clinical manifestations and reliance on nerve biopsy for definitive diagnosis. This study aimed to characterize the clinical, neurophysiological, and histopathological features of NSVN in a Brazilian cohort.

METHODS

We conducted a cross-sectional, ambispective cohort study combining retrospective chart review and prospective patient assessments. Inclusion required histopathological confirmation of isolated peripheral nerve vasculitis; cases with systemic or secondary vasculitis were excluded. Data collection included clinical evaluation, neurophysiology, and nerve biopsy.

RESULTS

A total of 14 patients were included (9 female, 64%; mean age: 61). Most (n = 8, 57%) had subacute onset of painful sensory or sensorimotor deficits. Multiple mononeuropathies predominated (n = 11, 78%), but a subset exhibited chronic progression (n = 5, 35%) and axonal polyneuropathy (n = 3, 21%). Electrophysiological studies revealed a consistent axonal pattern. Biopsies confirmed possible vasculitis in six (43%), and probable vasculitis in six (42%), with only two (14%) fulfilling criteria for definite vasculitis. Serologies were nonspecific. Treatment involved corticosteroid pulse therapy, with immunosuppression in refractory cases.

INTERPRETATION: These findings highlight that NSVN often presents with painful sensorimotor symptoms and may clinically mimic progressive axonal polyneuropathies. Given its potential for significant morbidity if left untreated, early recognition and consideration of nerve biopsy remain critical. The diagnostic complexity and variability in presentation suggest that NSVN may be underrecognized. We hope this cohort contributes to a broader understanding of its clinical spectrum and informs future diagnostic strategies.