[Vasculitis and diseases of the peripheral nervous system]

Vasculitis commonly induces peripheral neuropathies. Neuropathy is isolated in one third of the cases or participates in a multisystemic disorder. The pathological mechanism is tissular ischaemia induced by inflammation and lesions of vessel walls. Pathophysiological classification of vasculitis is mainly based on the size of affected vessels but other approaches may be proposed such as immunological classification considering the presence or absence of immunological markers. The diagnosis is supported by neuropathological examination of muscle and nerve biopsies, but electrophysiological testing may contribute to establish the diagnosis and the prognosis of the disease by showing the highly suggestive pattern of multitroncular involvement and by evaluating the extent of the neuropathy and of axonal loss. In most cases, treatment with steroids and other immunosuppressive agents result in good but partial improvement.