The female brain is more susceptible to lasting damage from a head injury and women are also more likely to sustain one. WH reports on why concussion is a female health issue
It was the middle of the night when Karen Murray’s daughter called out for her. Karen jumped out of bed. The next thing she remembers is her legs giving way from under her. She fell, hitting her head on the bedside table on her way down. ‘I blacked out,’ the 45-year-old mum of two says. ‘A few seconds later, I came to and got up, but I felt wobbly and nauseous.’ Her husband went to check on their daughter and Karen spent the next 20 minutes feeling as if she was going to throw up. When the nausea passed, she drifted back to sleep.
But the next morning, Karen woke with a pounding headache. The rest of that day – and the next – she had bouts of nausea and dizziness. Her mother, a nurse, urged Karen to go to A&E, worried that she had suffered a concussion. ‘I’d thought that only happened to [rugby] players or after a serious accident such as a car crash,’ she admits. And yet, when she went to the hospital, the doctor ordered a CT scan. Sure enough, Karen was diagnosed with a mild concussion.
Abigail Bretzin, a postdoctoral research fellow in the Penn Injury Science Center at the University of Pennsylvania, researches sex differences in concussion outcomes. She isn’t surprised Karen didn’t realise her head injury might be serious. ‘It hasn’t been recognised that concussion and traumatic brain injury happen as often as they do in women,’ she says. ‘In general, the focus has been on men and while men do have higher rates of concussion than women overall, we also know that women’s brains may be more vulnerable.’
Fibre optics
The word ‘concussion’ comes from a Latin word that means ‘to shake violently’, explains Dr Bretzin. ‘When you hit your head, the impact imparts forces to the brain and those forces lead to a cascade of events that can cause a range of symptoms,’ she adds. Douglas H Smith, director of the Penn Center for Brain Injury and Repair, studies the mechanics of concussion. ‘You can think of your brain as being like an electric grid, with a network of fibres coursing through it,’ he explains. ‘The impulse starts in the grey matter, on the outside of the brain, and moves through to the white matter on the inside, which is filled with axons – fibres so small and delicate that you’d need to put 100 of them side by side to equal the thickness of one human hair.’
The axons are like the brain’s wires in this electric grid, Dr Smith explains, transporting information from neuron to neuron so you can do everything from breathe and talk to read and move your muscles. The axons do this using the sodium chan
