Neuro-musculo-skeletal manifestations in primary Sjögren's syndrome.

Primary Sjögren's syndrome is a systemic autoimmune disorder whose main characteristics are dryness of the eyes and mouth, caused by lymphocytic infiltration of the exocrine glands. Patients may also show signs of extraglandular involvement of lung, liver, kidney and vessel walls, as well as of the central and peripheral nervous systems, muscles and joints. This article presents a review of the literature on extraglandular involvement of the peripheral and central nervous systems, muscles and joints. Several data support the hypothesis that vasculitis is the underlying mechanism. The need for an extended inventory of the extraglandular manifestations, preferentially linked to immunoserological and -histological investigations to gain more insight into the aetiology and pathogenesis is stressed. As far as the clinical picture is concerned, myalgia and arthralgia are often reported, but myositis and arthritis are rare. Data about the prevalence of peripheral and central nervous system involvement are conflicting: factors contributing to these differences are discussed. As insight into prognosis and therapy will strongly depend on the diagnostic criteria used, the need for international agreement on these is emphasized.