Many causes of dementia are neurodegenerative, and protein misfolding is a cardinal feature of these. Other common causes include vascular dementia, dementia with Lewy bodies, frontotemporal dementia, and mixed dementia (commonly Alzheimer's disease and vascular dementia). Less common causes include normal pressure hydrocephalus, Parkinson's disease dementia, syphilis, HIV, and Creutzfeldt–Jakob disease.