insufficient number of inclusions

Necrotizing Vasculitis are inflammatory diseases of the wall of vessels. Neurological damage of the peripheral nerve varies from 7% to 50% of cases depending on the type of Necrotizing Vasculitis.

Peripheral neurological impairment is rarely life threatening (except when associated with other visceral impairment which, in turn, require urgent management with a severity score defined by the Five Factor Score) but impacts the functional outcome by sequelae evaluated by the Vascular Disease Index (VDI).

Four retrospective studies were published with low number of participants, and also mix subgroups of vasculitis Anti-Neutrophil Cytoplasmatic Antibodies (ANCA)+/- GPA (Granulomatosis with polyangiitis), Eosinophilic granulomatosis with polyangiitis (EGPA), Microscopic polyangiitis (MPA), Polyarteritis nodosa (PAN), and Non Systemic Vasculitic Neuropathy (NSVN) and Systemic Vasculitic Neuropathy (SVN).

Overall, management of Necrotizing Vasculitis has evolved significantly over the last two decades, with a dramatic improvement in survival, thanks to new therapeutic strategies and medications. Five-year survival increased from 85% for diagnoses made between 1990 and 1999 to 94.5% for diagnoses made after 2010 Evaluation of relapses of vasculitis, late macro vascular complications, medical-economic evaluation of therapeutic strategies and functional impairment of neuropathies are at the heart of current medical concerns with a view to improve vital and functional prognosis.

Various tests for the evaluation of peripheral neurological damage appear to be relevant tools in vasculitis, although they are not specific: Muscular force scale Medical research council (MRC), Rasch-built overall disability scale (RODS), Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Construction and validation of the chronic acquired polyneuropathy patient-reported index (CAP-PRI), Health-Related Quality of Life (HR QOL), Medical Interview Satisfaction Scale (MISS), Neuropsychological Impairment Scale (NIS) associated to results of repeated Electromyography.

In this study, MRC, NIS and RODS measurements were chosen for their reproducibility and practicality.

In addition to the immediate or relapse mortality factors assessed by the five-factor score (FFS), a functional morbidity score specific to neuropathies related to necrotizing vasculitis must be developed, as well as the determination of the neurosensory disorders and macro-vascular complications. Therefore it is proposed in this observational study to determine the factors that can be predictive of the functional evolution, in order to build a risk score.

Inclusion Criteria:

Adult patient with an initial diagnosis or a relapse of :

- Systemic Vasculitic Neuropathy (SVN): Primary Necrotizing Vasculitis answering the Chapel Hill Consensus Conference criteria associated with a symptomatic Vasculitic Peripheral Neuropathy

Or

- Non Systemic Vasculitic Neuropathy (NSVN): pure symptomatic peripheral neurological impairment without systemic visceral impairment

Exclusion Criteria:

• Symptomatic peripheral neurological impairment not attributable exclusively to primary necrotizing vasculitis
• Diabetes
• Chronic ethylism
• AL (immunoglobulin light chain) amyloidosis or TTR (transthyretin)
• Genetic neuropathies
• Toxic neuropathies
• Sequelae of sciatica
• Opposition to participation in the study
• Lack of social security
• Under guardianship or curatorship

Patient with an initial diagnosis or a relapse of :

- Systemic Vasculitic Neuropathy (SVN): Primary Necrotizing Vasculitis answering the Chapel Hill Consensus Conference criteria associated with a symptomatic Vasculitic Peripheral Neuropathy

Or

- Non Systemic Vasculitic Neuropathy (NSVN): pure symptomatic peripheral neurological impairment without systemic visceral impairment