Some inflammatory diseases of the gastrointestinal system are associated with neurological symptoms which, in rare cases, may precede the onset of the gastrointestinal manifestation of the disease. Celiac sprue is characterized by an intolerance to the wheat protein gluten. The typical neurological manifestation of celiac sprue is cerebellar ataxia. The ataxia as well as the gastrointestinal symptoms can be treated with a strictly gluten-free diet. The neurological symptoms of Whipple's disease, a disorder caused by gram-positive bacilli, are variable. Typical symptoms of cerebral Whipple's disease include dementia, ophthalmoplegia, movement disorders, and signs of hypothalamic dysfunction. Nowadays, the diagnosis of cerebral Whipple's disease is made by PCR detection of the bacilli in the CSF. Crohn's disease and ulcerative colitis are associated with neurological symptoms to a similar proportion. Various forms of polyneuropathies have been observed. The CNS manifestations of inflammatory bowel diseases include thromboembolic stroke, cerebral venous thrombosis, and cerebral vasculitis.