Mild head injuries are often more serious than they might appear.
This article was first published in the March 28, 2015 issue of the New Zealand Listener.
About 34,000 New Zealanders suffer a mild traumatic brain injury (TBI) – or concussion – every year, mostly because of falls, blows to the head, car accidents or assaults. But for many of them, the consequences are far from mild.
According to the recent Brain Injury Outcomes New Zealand in the Community (Bionic) study, which looked at the incidence and consequences of all head injuries among 173,200 Waikato residents, more than 40% of the adults who suffered a mild injury were experiencing four or more symptoms of what is known as post-concussion syndrome a year later. Those symptoms include headaches, dizziness, forgetfulness, depression, anxiety, irritability and lethargy. Often they follow an apparently unremarkable “bang on the head”.
Knocks received on the rugby field are a high-profile cause of concussion. But the study suggests rugby is responsible for only 3% of head injuries. Waikato University psychology lecturer Nicola Starkey, one of the Bionic study researchers, says the focus on the sport is useful, though, as it helps raise awareness of head-injury dangers. “A lot of people still don’t realise that a bang on the head can actually cause long-term symptoms.”
Auckland psychologist Nic Beets, who helps run a head injury support group, says in some cases a person who hits her head after falling on a slippery path can end up experiencing more serious long-term health effects than someone who sustains a life-threatening head injury in a car accident.
“I’ve had people coming to my group after a relatively mild head injury saying they thought they were going crazy,” he says. “There’s this unfortunate thing where your injury gets classified according to how severe it looked at the time, rather than the long-term functional consequences.”
Wellington personal trainer Paula Wackrow didn’t think she was going crazy when, a few days after hitting her head on a piece of gym equipment, she woke with a bad headache, nausea and double vision. She knew something was seriously wrong.
“At first I thought it was because I didn’t have my glasses on, but then I realised that wasn’t the problem. I thought, ‘I’m in deep trouble.’”
After two weeks off work, she began to feel better, although she continued to have trouble concentrating – “I kept zoning out with clients and having trouble doing things like counting reps” – and had constant headaches.
Then she tripped and hit her head a second time, and her headaches became so debilitating that on several occasions she had to be hospitalised. She was also overwhelmed by “bone-deep fatigue”, as well as feelings of depression and anxiety.
Five months after the original head injury, Wackrow was diagnosed with post-concussion syndrome. She has now given up her job and is hopeful that with rest – the only effective treatment for the condition – she will eventually recover.
Recurrent brain injuries are common. According to the Bionic study, 10% of people have a second knock to the head within 12 months of the first one. They are significantly more likely to still be experiencing post-concussive syndrome a year later than those who have just one injury.
Starkey says recurrent brain injuries are also linked to problems such as early-onset dementia and Parkinson’s disease.
“That’s one of the reasons it’s so important for parents and sports officials not to force players back onto the field after they’ve had concussion,” she says. “Concussion is a brain injury, and it’s important to make sure they’re completely symptom-free before they start playing again.”
It’s hoped the next stage of the study will shed more light on why some people who experience a mild head injury recover quickly, whereas others with an apparently identical injury develop post-concussion syndrome. Starkey says one explanation may be their psychological state before the injury.
“If you have pre-existing anxiety or depression, then a TBI can trigger a worsening of that condition – it seems to tip the body over the edge.”
Genetic factors may also be involved, particularly those governing the brain’s inflammatory response to injury. That theory is now being tested by researchers at the University of Auckland, who are analysing saliva samples from Bionic study participants.
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