Scientists have discovered that a single severe head injury can lead to dementia through a rogue protein that propagates through the brain and corrupts others, giving some much needed insight into what happens inside an injured brain. ‘Brain injuries are one of the most complex pathologies in the most complex organ in the body, the brain,’ said Dr William Stewart, consultant neuropathologist at Queen Elizabeth University Hospital in Glasgow, UK. ‘We have tended to think of injuries in simplistic terms.’
In July, Dr Stewart and colleagues from Italy announced a discovery that might explain how brain injury can lead to dementia. A single severe injury caused a brain protein called tau to go rogue, slowly spreading through the brain and corrupting other tau proteins. This causes brain cell deaths and memory loss, and eventually dementia. Deformed tau is also present in the brains of patients with Alzheimer’s disease. By knowing more about how exactly brain injury is linked to dementia, Dr Stewart hopes that we might, in future, be able to identify rogue tau outbreaks in TBI patients, but also find ways to stop it from spreading.