Abstract / Summary
ABSTRACT Introduction/Aims Electrophysiologic features suggestive of demyelination have been reported in vasculitic neuropathy, complicating the diagnostic process, but their frequency is unknown. We aimed to determine the prevalence of demyelinating features, including fulfillment of European Academy of Neurology/Peripheral Nerve Society ( EAN / PNS ) electrophysiological criteria for demyelination in suspected CIDP , in a cohort of patients with biopsy‐confirmed vasculitic neuropathy. Methods Clinical data and nerve conduction studies from patients with biopsy‐confirmed vasculitic neuropathy (definite or probable) were retrospectively analyzed in two centers in France between 2014 and 2020. Results Sixty‐three patients were included (mean age 58 ± 16 years; 30% were male), including 28 with non‐systemic vasculitic neuropathy (NSVN) and 35 with systemic vasculitic neuropathy (SVN). Pain and sensory disturbances were present in all patients, whereas motor deficits occurred in 73% of patients. The predominant electrophysiological pattern was a symmetrical distal polyneuropathy ( n = 26). Twenty‐seven (42.9%) patients showed demyelinating NCS abnormalities, and 11 (17.5%) patients fulfilled the EAN/PNS criteria for demyelination. Motor conduction block was the most frequent demyelinating abnormality, followed by prolonged F‐wave latency. Demyelinating abnormalities were present in 7.1% of NSVN patients and 25.7% of SVN patients, with no statistically significant difference between groups. Discussion Electrophysiological patterns suggestive of demyelination are common in vasculitic neuropathy. Nevertheless, most patients presented with pain and a symmetrical distal polyneuropathy, a phenotype not typically associated with demyelinating neuropathy. Future studies integrating detailed clinical data may help identify key diagnostic features and improve recognition despite potentially misleading electrodiagnostic findings.