Peripheral nervous system lesion in systemic vasculitis - issues of diagnosis and treatment

Vasculitis is a clinically diverse group of diseases with histopathological signs of blood vessel inflammation, which contributes to vascular damage and ischemic damage to the affected tissues. Vasculitic neuropathy is a common complication of the primary systemic vasculitides, such as polyartertis nodosa and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, systemic diseases of the connective tissue - systemic lupus erythematosus and Sjogren syndrome, vasculitis associated with infection, most often viral hepatitis C and B and non - systemic vasculitis neuropathy. Vessels of medium and small caliber are involved in the pathological process in these diseases. With all vasculitis, except for those caused by the direct effect of the infectious trigger on the blood vessel walls, the main pathogenetic mechanism is an autoimmune process with the development of vasa nervorum vasculitis - small arteries and vessels that supply peripheral nerves, and the outcome - nerve ischemia. The classic clinical presentation is an acute or subacute painful multifocal neuropathy that has a predilection for the lower extremities, affects two or more named nerves, and progresses in a step wise manner. However, vasculitic neuropathy can manifest in a variety of ways, including asymmetric polyneuropathies and distal symmetric sensory neuropathies, and it also can be slowly progressive, particularly in cases of nonsystemic vasculitic neuropathy (NSVN), a form of vasculitis that clinically remains restricted to peripheral nerves. Nerve biopsy can help establish the diagnosis of a systemic vasculitis, particularly when other organ involvement is not clinically apparent, and is required for diagnosis of NSVN. Neuropathy due to systemic vasculitis should be treated in accordance with the recommendations for the treatment of the underlying disease. In NSVH, the main medicine of choice are glucocrticoids, and in severe/progressive cases, pulse therapy with cyclophosphamide.