Vasculitic neuropathy: Comparison of clinical predictors with histopathological outcome

Abstract

Introduction:To improve diagnostic accuracy, in this study we compared prebiopsy clinical parameters with subsequent pathological confirmation of peripheral nerve vasculitis. Methods: Clinical, laboratory, and neurophysiological parameters were analyzed for consecutive patients referred for nerve biopsy with suspected vasculitis. Patients were assigned pathological categories of definite, probable, possible, or absent vasculitis using validated guidelines. Patients with definite or probable vasculitis were considered to have pathologically confirmed vasculitis. Results: From a cohort of 78 patients, biopsy confirmed vasculitis in 29.5%. Parameters that best differentiated between pathologically confirmed and pathologically unlikely vasculitis were stepwise clinical progression (34.8% vs. 5.6%), the presence of serum anti‐myeloperoxidase antibody (28.6% vs. 2.2%) and rheumatoid factor seropositivity (38.1% vs. 10.7%). Pathologically absent vasculitis was frequent in patients with normal (100%) or primarily demyelinating (87.5%) nerve conduction studies. Discussion: Factoring the negative predictors of pathologically confirmed vasculitis into decision‐making can reduce the frequency of diagnostically unhelpful nerve biopsies. Muscle Nerve 59:643–649, 2019

Lower Limbs Axonal Neuropathy in Polyarteritis Nodosa with Onset of Neuropathic Symptoms

“…In our study, the characteristics of peripheral neuropathy in PAN patients are consistent with asymmetric axonal neuropathy that has a predilection for the lower extremities, affects distal limbs more severely than proximal, and involves both motor and sensory nerves. Previous studies have shown that sensorimotor abnormalities on NCS and the presence of a pure axonal neuropathy were most consistent with pathologically con rmed vasculitis 25,26 , which is consistent with our ndings. The lower limb is the most susceptible to nerve injuries in PAN patients, since the high frequent of disease onset rate appeared at lower limb in the clinical data and the abnormal amplitudes of peroneal and sural nerve were detected in NCS.…”

The utility of nerve biopsy in carefully selected patients in modern neuromuscular practice

“…Not surprisingly, demyelinating and normal nerve conduction studies, cerebrospinal fluid pleocytosis, and pure motor syndromes are very rarely associated with vasculitis on nerve biopsy. These findings are certainly in line with previously published literature, and this approach can serve as a guide for deciding which patients should have a nerve biopsy …”

“…These findings are certainly in line with previously published literature, and this approach can serve as a guide for deciding which patients should have a nerve biopsy. 1 Overall, nerve biopsy is being performed less frequently in modern medical practice, but Nathani et al point to a key area (vasculitis) in which nerve pathology results are still very useful for obtaining a diagnosis. Given the high-risk and extended treatment regimens necessary for successful treatment of necrotizing large arteriole vasculitis, a degree of certainty regarding the diagnosis is important.With recent advances in other areas of neuromuscular medicine (such as imaging and genetics), we have encountered some neuromuscular specialists who believe that nerve biopsy is becoming obsolete and argued that it should be used primarily as a research tool.…”

Nerve biopsy: Current indications and decision tools

“…Optimal outcomes with nerve biopsy requires appropriate selection of patients, 153 nerves and neuropathology techniques. No guidelines exist to inform patient selection for nerve biopsy.…”