A study of Danish skulls showing signs of healed fractures revealed that men living during Medieval times in Europe had an increased risk of dying -- even after surviving an axe to the head. Those recovering from head injuries had a 6 percent higher risk of early death than men without similar trauma, according to findings published in the Proceedings of the National Academy of Sciences this week.
Skeletons are a good way to measure the extent to which modern care has improved the outlook for survivors of severe skull trauma. Neuro-cranial fractures have always taken a toll on human populations, and even today, the aftermath of head trauma is a major concern in medicine. Many studies have focused on prehistoric and historic mortality -- but few have quantified the long-term health risks of skull fractures in Medieval and early modern societies.
So, an international trio led by Jesper Boldsen from the University of Southern Denmark and Penn State’s George Milner examined 236 adult male skulls from three Danish cemeteries dating back between the 12th and 17th centuries. (Only males were included in the study because females had too few cranial fractures by comparison.) They found that 8.9 percent of the skulls from males ages 15.5 and older had healed cranial vault fractures. Many were simple depressions, though some showed signs of deep cuts made by heavy, sharp-edged weapons, like a sword or an axe. Despite their injury, these men lived for a prolonged period afterwards, judging from the considerable amount of bone remodeling. However, the researchers don’t know for sure what killed them in the end. (Their eventual death could have been totally unrelated to that same act of interpersonal violence.)
The team then compared the long-term survival of men with cranial injuries to the life expectancy of men without the same types of trauma. They looked at the age when the fracture was received and the age when the victims died, Science reports, and then calculated whether severe head trauma increased the victim’s odds of dying in the following years. The risk of early death, their model showed, was 6.2 times higher for men with cranial fractures than for their uninjured counterparts.
That’s about double the risk of early death in modern people with traumatic brain injuries, and that the difference is likely due to the improvements in medical care and support over the centuries. Their approach of quantifying the increased risk of dying for men with healed cranial vault fractures can be adapted to any pathological condition and extended into different periods of time.