Non-systemic vasculitic neuropathy: single-center follow-up of 60 patients

Abstract

The objective of this study is to report the clinical presentation and long-term outcome of patients with non-systemic vasculitic neuropathy (NSVN) seen at our neuromuscular center. In this retrospective analysis, we assessed medical records of 60 patients with biopsy-proven NSVN (39 men, 21 women; median age: 64 years, 24-80), who were seen at our department between 1999 and 2008 and were followed up until 2014. The initial neurological findings, laboratory and neurophysiological data, treatment regimens, and outcome were analyzed in all patients. NSVN was mostly asymmetric (48/60, 80%), sensorimotor (45/60, 75%), and painful (38/60, 63%), with walking impairment as one major sign (51/60, 85%). No compound action potentials could be recorded in 29/60 (48%) sural nerves (later biopsied side) and in 6/60 (10%) tibial (motor) nerves. Pathology of sural nerve was informative in all cases irrespective of neurophysiological findings and prior immunosuppression. After initial treatment with i.v. methylprednisolone, all patients reported overall improvement. Of the 46 patients who were followed for >1 year, those with mild to moderate affliction were stable with azathioprine (19/46, 41%), while 18/46 (39%) patients were treated with cyclophosphamide and other immunosuppressants due to progression or relapse. At 4 years, 24/46 (52%) patients had either discontinued (n = 21) or had primarily refused immunosuppressive treatment (n = 3) without relapse. Age younger than the group median of 64 years was associated with better outcome. No patient evolved to systemic vasculitis. NSVN is a potentially treatable disorder of the peripheral nervous system.

The nonsystemic vasculitic neuropathies

“…Median duration of symptoms at diagnosis is 2.5-12 months 13,19,31,[35][36][37][38] . In one study, the median delay to diagnosis was 2 years; combined with the relatively mild neurological involvement in this cohort, this delay suggests a bias against inclusion of more severely affected patients 30 . Unusually long delays of 8-13 years have occurred in most series, highlighting the need for vigilance for NSVN in patients with long-standing neuropathies 23,30,35,36 .…”

“…In one study, the median delay to diagnosis was 2 years; combined with the relatively mild neurological involvement in this cohort, this delay suggests a bias against inclusion of more severely affected patients 30 . Unusually long delays of 8-13 years have occurred in most series, highlighting the need for vigilance for NSVN in patients with long-standing neuropathies 23,30,35,36 . Three patterns of clinical involvement in NSVN have been identified: multifocal neuropathy, asymmetric polyneuropathy (also commonly known as overlapping multifocal neuropathy), and distal symmetric polyneuropathy.…”

“…course, but the disease steadily progresses in 40% 3,19,34,35 . Approximately 5-10% of patients present with acute, rapidly progressive deficits and are diagnosed within 1 month, but most patients progress subacutely or chronically 30,31,[35][36][37] . Median duration of symptoms at diagnosis is 2.5-12 months 13,19,31,[35][36][37][38] .…”

“…Sensory loss usually involves both large-fibre and small-fibre modalities; a purely small-fibre neuropathy is exceptional. Pure motor presentations are also rare 30 . Vasculitic neuropathy is generally considered to be a painful neuropathy, but our review of the literature has identified that 20% of patients with NSVN have no pain.…”

“…Information about the treatment of NSVN with azathioprine is provided by a 2015 study that involved 60 patients with NSVN 30 . Nineteen of the 60 patients were initially treated with pulsed intravenous methylprednisolone, combined with an oral corticosteroid taper in nine patients, followed by 150 mg azathioprine daily.…”