Headaches in dementia. We investigated 288 elderly subjects with various degree of dementia, focusing on headaches. Seventy-three of 288 elderly subjects (25.3%) complained of some headaches. The most common type was the tension-type headache, from which 43 of the 73 subjects with headaches (58.9%) suffered. The degree of cognitive disturbances, evaluated by Hasegawa's intelligence scale, significantly correlated to the prevalence of headaches, and indicated that patients with dementia appeared to have less headaches. The methodological issues and views on headache research in dementia were assessed, and it is concluded that the field is a difficult one, with potential for error. 