Dementia is a global burden of public health. Headache disorders are the third most common cause of disability worldwide and common problems in the elderly population. Few studies focused on the relationship between primary headache disorders (PHDs) and cognitive status, and the results remain controversial. The aim of this countrywide, population-based, retrospective study was to investigate potential association between PHDs and dementia risk.We enrolled 1346 cases with PHDs to match the 5384 individuals by age, gender and co-morbidities. The definition of PHDs, dementia, and risk factors of dementia was identified according to The International Classification of Diseases, Ninth Revision, Clinical Modification. Cox regression was administered for estimating hazard ratios (HR) for dementia.During more than 5 years of follow-up, PHDs individuals had 1.52 times (P <.05) greater risk to develop all dementia compared with individuals without PHDs. Elderly (aged ≥65 years) patients with PHDs displayed significantly higher risk to develop all dementia (P <.01) and non-Alzheimer non-vascular dementia (NAVD) P <.01). Female PHDs individuals were at higher risk of suffering from all dementia (P <.05) and NAVD (P <.05). The influence of PHDs on all dementia was highest in the first 2 years of observation.The results indicated PHDs are linked to a temporarily increased risk for dementia, mainly NAVD, with age-specific and gender-dependent characteristics.

BackgroundHeadache such as migraine is associated with stroke. Studies focused on primary headache disorders (PHDs) as a risk factor for stroke are limited. The purpose of this population-based cohort study was to explore whether patients with PHDs were at a high risk for developing stroke.MethodsA total of 1346 patients with PHDs were enrolled and compared with 5384 age-, gender- and co-morbidity-matched control cohorts. International Classification of Diseases, Clinical Modification codes were administered for the definition of PHDs, stroke, and stroke risk factors. Cox proportional-hazards regressions were performed for investigating hazard ratios (HR).ResultsPHDs patients exhibited a 1.49 times (95% CI :1.15–1.98, p < 0.01) higher risk for developing ischaemic stroke compared with that of control cohorts. Both migraine (HR = 1.22, 95% CI :1.13–1.97, p < 0.05) and tension-type headache (HR = 2.29, 95% CI :1.22–2.80, p < 0.01) were associated with an increased risk of ischemic stroke. Females with PHDs were at greater risk of developing ischaemic stroke (HR = 1.49, 95% CI :1.13–1.90, p < 0.01) than those without PHDs. PHDs patient aged 45 to 64 years displayed significantly higher risk to develop ischaemic stroke (HR = 1.50, 95% CI: 1.11–2.10, p < 0.05) than the matched controls. The impact of PHDs on ischaemic stroke risk became gradually apparent by different following time intervals beyond 2 years after first diagnosis.ConclusionPHDs is suggestive of an incremental risk for ischaemic stroke with gender-dependent, age-specific and time-dependent characteristics.Electronic supplementary materialThe online version of this article (doi:10.1186/s10194-016-0701-2) contains supplementary material, which is available to authorized users.