This chapter describes how various systemic inflammatory or immunological disorders systemic inflammatory or immunological disorders can affect the nervous system. Such autoimmune rheumatological disorders include systemic lupus erythematosus, rheumatoid arthritis, and Reiter’s disease; vasculitic disorders include giant cell arteritis, vasculitic disorders include giant cell arteritis and the primary and secondary vasculitides. Other autoimmune and inflammatory conditions diseases affecting the nervous system include ulcerative colitis and Crohn’s disease, Whipple’s disease, coeliac disease, Other autoimmune diseases affecting the nervous system include Behçet’s disease, and sarcoidosis, ulcerative colitis and Crohn’s disease, Whipple’s disease and coeliac disease. Thyroid disease may also be associated with immunologically driven neurological complications including dysthyroid eye disease—Graves’ ophthalmoplegia and Hashimoto’s thyroiditis-associated encephalopathy.