Chronic pain: discovering why it happens to some of us and not others
Rhiannon Bannenberg is just one of the 462,000 Australians who suffer from chronic pain.
Photo: Since the age of 13, Rhiannon Bannenberg has been suffering from the effects of chronic pain. Now aged 25, she's expanded her treatment and searched for answers outside of surgery or medication.
At the age of 13, Ms Bannenberg suffered spinal fractures and other injuries in a serious horse riding accident.
One year after initial treatment the aftermath of the damage became more apparent, with Ms Bannenberg transitioning from acute to chronic pain.
The conversation shifted from finding a cure to ongoing management.
"I had real physical damage that we could see on MRIs, on X-rays," she told Dominic Knight on 702 ABC Sydney.
We're about now where depression was 18 years ago — patients are stigmatised, unrecognised.
Professor Michael Cousins, expert in pain management
But it was the residual pain from the injury that began to take over, becoming an unwelcome fixture in her early teenage years and still remains with her today.
"That was a shock for me because I didn't expect it to be something that was going to last for a long time," she said.
"Particularly after it had been going on for a few years, it really wears you down. "Anyone who has chronic pain will understand; it interrupts your sleeping patterns, it really brings down your mood."
Now 25, Ms Bannenberg continues to experience chronic pain and has tried a combination of treatments to try and heal her body.
"A lot of the people around me have been very understanding but it has been difficult because a lot of chronic pain is invisible," she said. "You don't want people to feel sorry for you. It's not about the sympathy vote; it's about making sure that people understand that sometimes someone can appear perfectly fine but, underneath, there is something else going on."
Why pain becomes chronic in some people and not others
Internationally-recognised pain specialist Professor Michael Cousins has more than 50 years' experience in the field and is director of the Pain Management Research Institute at Sydney's Royal North Shore Hospital.
"Acute pain is a symptom, it tells you something is wrong and it's a warning system," he explained. "Chronic pain is a condition and I believe it's a disease, a chronic disease in its own right."
According to Professor Cousins, pain becomes chronic when it persists beyond the expected timeframe of healing, typically at the three-month mark. While acute pain resolves in most people during that time, the mechanisms for acute pain don't switch off for all.
"There may have been some damage to nerves during the injury, during the surgery, and the body is trying to compensate for that," he said. "We call [that] Central Nervous System Sensitisation. It stays like that, it just keeps going, and there becomes a deficit of one of the body's most important pain chemicals, called GABA."
The current options for treating chronic pain
Professor Cousins advocates a multi-modal approach and said while pain relief drugs were available, they should not be the only approach considered.
"Unfortunately, there's a lot of emphasis on the use of opioid drugs like morphine, which is extremely helpful after surgery or injury if the pain is severe," he said. "These drugs are not desirable for long-term chronic pain because they can help desensitise the nervous system."
Professor Cousins said that evidence was accumulating in favour of cognitive behavioural strategies, like meditation, by way of undoing some of the neural pathways linked to the pain.
"Whether we can do that with medications that we have currently is questionable," he said. "It certainly does diminish the pain to some degree; whether this turns the pain off remains to be seen. There are some excellent advances in knowledge of physical activity and pain and this is where the physiotherapist and occupational therapist come in."
He said these new mechanisms could potentially reduce the pain, and wind back the negative changes to the brain that occur in chronic pain.
Professor Cousins advises seeking a referral to a pain specialist if a patient's GP does not have access to other strategies for the management of chronic pain.
For people in severe pain, he said interventions and invasive procedures were possible.
"Pain is incredibly pervasive, it pervades every aspect of a person's life and their families and very often their community," he said. "It would be without any doubt the largest, unrecognised, chronic condition of all the chronic diseases. We're about now where depression was 18 years ago — patients are stigmatised, unrecognised."
Using our genetics to solve the future of pain management
Looking ahead, Professor Cousins said there was promise in more advanced treatments including neuromodulation.
We know now that there's a small family of genes associated with certain types of nerve damage pain, not a single gene, it's a group of genes.
Professor Michael Cousins
Based on the Gate Control Theory of Ronald Melzack and Patrick Wall, he said the theory said a gate in the spinal cord could either let pain messages in or close and prevent them from reaching the brain.
"It's a lot more complicated than that, but that brief description has turned out to be absolutely correct," he said. "You can use little, tiny pulses of electricity and designing the targets for how that electricity gets to the spinal cord and brain is a big challenge."
Professor Cousins said he felt the most exciting and promising area of pain treatment was in the genetics area.
"In a large amount of medicine now it's being recognised that epi-genetics plays a very big part in various chronic diseases," he said. "Epi-genetics means an interaction between the individual's genetics and their environment, both internal and external. We know now that there's a small family of genes associated with certain types of nerve damage pain, not a single gene, it's a group of genes."
Professor Cousins said that those with a genetic susceptibility to chronic pain could someday be warned via a DNA test of whether surgical options could trigger a painful recovery.
"Sadly at the moment, virtually no patients are told before surgery that you have about a 10 or 20 per cent, depending on the size of the surgery, you have about that risk of developing ongoing pain."
This interview was conducted during National Pain Week.
Posted 27 Jul 2015, 11:43am