Hyperostosis frontalis interna: Observed patterns, prevalence, and dementia associations in older adults

Hyperostosis frontalis interna (HFI) is a frequently underrecognized condition characterized by overgrowth of the frontal endocranium, most commonly observed in post-menopausal women. Although its etiology remains unclear, hormonal influences and a possible relationship with neurocognitive changes have been proposed. This study aimed to examine the prevalence, morphological pattern, and observe potential associations between HFI, sex, and dementia in an older adult cadaveric sample. Twenty-six dry calvaria (12 male, 14 female; ages 61-94 years) from donated cadavers were evaluated for the presence and type of HFI. HFI severity was categorized into four types (A-D) based on established morphological criteria. Demographic characteristics and documented dementia history were recorded to explore potential associations with HFI severity. HFI was identified in 17 of 26 calvaria (65.4%) with Types A and B being most common in this population. 10 cases (38.5%) demonstrated both HFI and a documented history of dementia. In this sample, individuals with HFI and dementia were older on average (86.3 years) than those with HFI and no dementia (83.8 years). HFI occurred predominantly in females and tended to be more advanced in cases with dementia. Findings from this cadaveric sample support prior reports that HFI is prevalent in older post-menopausal women and may remain prevalent in older populations. The co-occurrence of more severe HFI with dementia history aligns with literature suggesting that extensive frontal bone thickening may contribute to or reflect neurocognitive changes. Although causation cannot be established, these results highlight the need for heightened clinical awareness of HFI and further research integrating anatomical, radiological, and clinical data to clarify its potential cognitive implications.