[Peripheral neuropathies during systemic diseases: Part II (vasculitis)]. / Neuropathies périphériques au cours des maladies de système : partie II (vascularites).

Primary systemic vasculitides, mainly of the small and medium-sized vessels, are frequently associated with peripheral neuropathies. When the disease is already known, the appearance of a neuropathy should suggest a specific injury, especially when associated with other systemic manifestations. Conversely, when neuropathy is inaugural, close collaboration between neurologists and internists is necessary to reach a diagnosis. A standardized electro-clinical investigation specifying the topography, the evolution and the mechanism of the nerve damage enables the positive diagnosis of the neuropathy. Several elements orient the etiological diagnosis and allow to eliminate the main differential diagnosis: non systemic vasculitic neuropathy. The existence of associated systemic manifestations (glomerular or vascular nephropathy, interstitial lung disease, intra-alveolar hemorrhage, ENT involvement…), biological markers (ANCA, cryoglobulinemia, rheumatoid factor), and invasive examinations allowing histological analysis (neuromuscular biopsy) are all useful tools for.

[Peripheral neuropathies during systemic diseases: Part I (connective tissue diseases and granulomatosis)]. / Neuropathies périphériques au cours des maladies de système : partie I (connectivites et granulomatoses).

Systemic diseases (connective disease, granulomatosis) may be associated with peripheral neuropathies. The diagnosis can be complex when the neuropathy is the presenting manifestation of the disease, requiring close collaboration between neurologists and internists. Conversely, when the systemic disease is already known, the main question remaining is its imputability in the neuropathy. Regardless of the situation, the positive diagnosis of neuropathy is based on a systematic and rigorous electro-clinical investigation, specifying the topography, the evolution and the mechanism of the nerve damage. Certain imaging examinations, such as nerve and/or plexus MRI, or other more invasive examinations (skin biopsy, neuromuscular biopsy) enable to specify the topography and the mechanism of the injury. The imputability of the neuropathy in the course of a known systemic disease is based mainly on its electro-clinical pattern, on which the alternatives diagnoses depend. In the case of an inaugural neuropathy, a set of arguments orients the diagnosis, including the underlying terrain (young subject), possible associated systemic manifestations (inflammatory arthralgias, polyadenopathy), results of first-line laboratory tests (lymphopenia, hyper-gammaglobulinemia, hypocomplementemia), autoantibodies (antinuclear, anti-native DNA, anti-SSA/B) and sometimes invasive examinations (neuromuscular biopsy).

Neuropathies périphériques associées aux syndromes lymphoprolifératifs : spectre clinique et démarche diagnostique.

Lymphoproliferative syndromes (multiple myeloma, Waldenström's disease, chronic lymphocytic leukemia, lymphomas) may be associated with peripheral neuropathies. The mechanism can be dysimmune, associated or not with monoclonal gammopathies; paraneoplastic; infiltrative; or more commonly, iatrogenic or due to vitamin deficiency. The diagnosis can be complex, especially when the neuropathy is the presenting manifestation, requiring a close cooperation between internists and neurologists. The positive diagnosis of the neuropathy is based on a systematic electro-clinical investigation, which specifies the topography and the mechanism of the nerve damage, sometimes reinforced by imaging examinations, in particular, nerve and/or plexus MRI. The imputability of the neuropathy to a lymphoproliferative syndrome is based on a set of arguments including the clinical context (B signs, tumour syndrome), first-line laboratory tests (hemogram, protein electrophoresis, viral serologies, complement), auto-antibodies discussed according to the neuropathy (anti-MAG, anti-gangliosides) and sometimes more invasive examinations (bone marrow or neuro-muscular biopsies).