A large assortment of comorbid diseases is associated with AD. There is evidence that chronic diseases, including diabetes, cardiovascular disease, depression, and inflammatory bowel disease, may be associated with enhanced risk of AD. Disruption in certain shared biological pathways has been suggested as the underlying mechanism for the relationship between AD and these diseases. Particularly, inflammation is a common dysregulated pathway shared by most of the diseases associated with AD. We examined the co-occurrence of certain diseases with AD as reflected by the co-occurrence of the respective concepts in the documents of the CAS Content Collection (Figure ). Dementia and inflammation are between the expected co-occurrences. With respect to cancer, inverse occurrence of cancer and Alzheimer disease has been reported: patients with dominant cancer had a 43% lower risk of developing AD, and those with prevalent AD had a 69% lower risk of being diagnosed with cancer. Stroke has been reported to be associated with AD among elderly patients. The relation is strong in the presence of certain vascular risk factors. Recently, there is accumulating evidence demonstrating that hyperglycemia is a potential risk factor for the development of cognitive impairment or AD. It has been reported that AD patients have a high risk of developing certain types of epilepsy and subclinical epileptiform activity.