Surprising new treatments for chronic pain
As opioids fall out of favour in the treatment of chronic pain, therapists are harnessing new technology to help patients.
“I woke up and thought, ‘Oh, my word, I’ve lost my job, I’ve almost lost who I am and I don’t know what is ahead for me now.”
Rickhuss-Bennett, 41, has developed complex regional pain syndrome, a condition that causes chronic pain after an injury. It means that her pain, once confined to her elbow, now affects her whole left side, from her eye to her leg, often leaving her weak and nauseous.
But for 30 minutes each week, in a nondescript treatment room at the Greenlane Clinical Centre in Auckland, she dons a virtual reality mask and steps into a near pain-free world. The transformation is almost instantaneous. Before strapping on the headset, she is clearly unwell, sipping from a water bottle and grimacing through another agonising spasm. Minutes later, playing a game called Fruit Ninja, she is determined and focused, building points by using controllers in her hands to slash and skewer a virtual smorgasbord of fruit shooting towards her.
“I can’t explain it,” she says. “You just get absorbed – you feel completely different. It’s addictive and you can’t not do it. It’s like, I don’t care, it’ll hurt, but I’m going to get all the fruit.”
The Auckland Regional Pain Service (TARPS) introduced virtual reality technology about six months ago and physiotherapists running the programme say it’s becoming a useful and popular tool to help patients like Rickhuss-Bennett conquer chronic pain.
“It’s been great,” says senior physiotherapist Murray Hames. “It’s not a panacea, but it’s a good way of providing graded exposure to more activity. It’s fun and it’s motivating. In chronic pain, usually the physical injury has healed but the pain messages remain amplified in the nervous system and brain. Slowly increasing activity is one of the best ways to re-wire the nervous system and alter those pain messages in the brain.”
Virtual reality games, he says, are likely to work by altering the neuroplasticity of the nervous system. They’ve been successful internationally in acute pain relief, but their use for chronic pain is relatively new and research into the brain mechanisms involved is still in its infancy. Some investigators believe the technology works mainly by distraction: the brain power that would otherwise go into processing and perceiving pain is diverted. It’s more successful when a gaming element is introduced, because that triggers reward pathways.
“Nerves that fire together, wire together, the saying goes,” says Hames. “So if you do something and it hurts, pretty soon you can just do the thing and you’ll hurt for the sake of it – there doesn’t have to be a pain stimulus. But it can also work the other way around.”
One game that’s used for those with lower-back pain has patients ducking and weaving through a tunnel to avoid being hit by virtual falling rocks. “Normally patients would find these movements very challenging, but they seem to be able to move very freely and spontaneously in a VR game,” says Hames. “For a new generation, particularly, it’s very powerful. We don’t know what the long-term benefits are, but it doesn’t look like there are any significant downsides.”
He’s had six patients use the new technology; four have made good gains while two have been “a bit unnerved” by it.
Physiotherapist Cat Pollard, who works with Rickuss-Bennett, says staff always test the games before using them with patients. “The only one we wouldn’t get a patient to do is the skiing – it’s disorienting and fast and you feel very unsteady. Murray nearly went flying through the wall when he tried it.”
Before the new technology was introduced, patients played video games to get them moving, but the virtual reality headsets have taken things to a new level, she says.
Rickhuss-Bennett, who once couldn’t lift her arm high enough to shampoo her hair, or grip with her hand, can now do both, thanks in part to the new confidence the game inspires in her. “It’s fun, that’s the best bit. You are doing physio and it’s hard and it can be disheartening. Then you come in here and you leave on a high.”
The mother of two had to give up her job as a PA in a legal firm after her accident and has no idea when she might be well enough to return. She’s still on medication for pain, depression and anxiety, and also battles exhaustion. But the VR therapy has made her more optimistic about the future. “It’s amazing – it makes me think differently, that yes, I can do it.”
One of the games she’s played at Greenlane, an archery simulator called Quiver, has made her keen to take up the sport in “real life”. She also hopes to buy VR equipment to use at home, and play the games with her young sons.
Doctors and scientists have long understood that chronic pain like Rickhuss-Bennett’s and acute pain are very different beasts, but the VR technology is one way they’re harnessing that knowledge to explore new ways of rewiring neural pathways.
The acute pain we feel when we twist an ankle or burn our hand on the stove is part of the body’s warning system, telling us to get an injury treated, or to stop doing something causing harm. Chronic pain, however, doesn’t serve any useful purpose and is the result of how the spinal cord and the brain are mis-managing pain signals.
Think of it like an electric guitar and amplifier, says neurophysiologist Dr David Rice, a senior lecturer and researcher at the Auckland University of Technology, who works with chronic pain patients at Waitemata Pain Services.
“The guitar strings are the sensors in the peripheral tissue that say something is wrong. Then we have an amplifier to make the sound louder. The amplifier is more like the spinal cord and the brain, and ultimately the pain experience is how loud the sound comes out. To make the sound louder, you can strum the strings harder – activating the danger signals in the peripheral tissue – or you can turn up the volume on the amp. Often in chronic pain, it’s almost as if the pain system learns to produce pain much better, and those changes primarily occur in the spinal cord and the brain.”
A big thrust of research locally and internationally is to investigate and measure these changes. Rice is one of the investigators on a study to examine the effects of non-invasive brain stimulation – firing weak electrical signals from small electrodes attached over the motor area of the brain – in people with long-term nerve-related arm pain. Patients received either five days of actual or placebo treatment and were followed for seven weeks to see if the technique can “turn down” the pain in the brain. The results are still being analysed.
MRI and other imaging techniques such as spectroscopy allow scientists to examine structural changes, chemical balance and neuro-connectivity in the brain. Variations can depend on the source of the pain. “People with arthritis will have slightly different patterns [on an MRI] to someone with back pain, for example, but generally speaking, there are common areas that we know are involved in producing the pain experience,” says Rice. “Some of the limbic centres – the emotional centres – seem to be particularly affected.”
Rice is co-supervising a PhD by consultant anaesthetist Daniel Chiang, who’s investigating genetic and other factors that might explain why some women develop chronic pain after breast cancer surgery. “Studies tend to show that, depending on the chronic pain condition looked at, between 20 per cent and maybe up to 60 per cent of the risk is genetic in nature. Tens or even hundreds of genes are potentially involved, with each conferring a small amount of risk.”
Chiang will measure some of those genes, and test the sensitivity of the pain system before the women have surgery. The 200 study participants will be followed for six months after surgery. He hopes the differences between those who do or don’t have chronic pain will help him work out what factors may be able to be predicted and prevented pre-operatively.
In chronic pain, says Rice, there’s little relationship between the amount of pain we feel and what’s actually happening in the tissues. “There are some types of chronic pain where there is ongoing tissue damage – problems such as osteoarthritis, for example – but also some where we don’t think there is any ongoing tissue damage yet the pain persists.”
X-rays aren’t that good at predicting how much pain a patient might have. “About 10-15 per cent of people who have a pristine knee X-ray with no evidence of any osteoarthritis or joint damage will have severe knee pain. And about 40-50 per cent of those with clear evidence of joint damage and what looks like moderate to severe osteoarthritic changes have never experienced pain in their life.”
When patients have a “volume control” problem with their pain, it can make them more sensitive to stimuli in other parts of the body. For example, a patient with knee pain is not only more sensitive to pressure or heat over their knee, but also when it’s applied to their shoulder, where they don’t have any pain.
“It can become a constellation of overlapping symptoms where people say, ‘Well, I’ve got fibromyalgia, but I’ve also got irritable bowel syndrome.’ We used to think there was potentially something wrong in the musculoskeletal system, and something wrong in the gut, but actually we’re beginning to realise that the central feature may be this overactive pain system.” The longer pain persists, he says, the more likely the problem is to do with that volume control knob.
For anaesthetist and pain management specialist Dr Kieran Davis, the biggest treatment change for the 800 people TARPS sees annually has been the phasing out of opioids since the late 1990s. They haven’t been used at all since about 2004. “They don’t work. Over time, patients become tolerant and resistant, and as you take more you repeat the cycle until you’re taking too much. And at high doses, you can get opioid-induced pain, so they become part of the problem.”
A review of patients a few years ago found about 20 per cent were on opioids when they came to the clinic. Outside Auckland, where there are few pain clinics, “they’re still back where we were 15 to 20 years ago”, with patients more likely to be prescribed opioids for chronic pain, sometimes in very high doses. “One patient from down country could barely talk [when he arrived],” says Davis.
Getting medications working well and most effectively in the right combinations is always a balancing act because of side effects, but after that, the treatment focus shifts to function and cognitive behavioural issues. By the time patients get to the pain clinic, they’ve been grappling with their pain for an average of five years and their fitness has deteriorated so much it’s often part of the problem. “They’ve either lost their fitness, or never had it. People who seem to have been very fit and then lose it get more pain than people who’ve never been fit.”
Commonly, patients have stopped moving the bit that hurts. “They’ve been told to not move, by GPs, physios, chiropractors, surgeons. It used to be ice, rest, elevate… but rest doesn’t treat the injury. GPs might say it’s time to get going again, but whether people then do that is another thing.”
Some patients are surprised at the “get moving” message, says Davis. “I had a big falling out with a patient about it because everyone had told him that if it hurts, stop.”
It’s important that movement increases gradually. “Building up strength and endurance takes time. You cannot force your way through the pain barrier. It’s more like a trampoline on its side and generally the harder you go at it, the further you bounce back. You can’t run a marathon today, but you can train to run a marathon.”
Patients are predominantly of working age. “You’d think we’d get a lot of older people, but we don’t. They often have pain, but they don’t have the psychosocial issues that go with it – it’s kind of an expected part of getting old.”
Davis says he always has a psychologist alongside at patient pain assessments, and though the pain clinic doesn’t take a psychotherapeutic approach, mental and physical wellbeing are inextricably linked.
“It’s like the onion ring. You start off with pain and injury, then you lose your job and have a financial problem and you get all the stresses related to losing your job. Then there’s compassion fatigue among your friends and they disappear because they’re sick of talking about your problems, and you don’t go out because you physically can’t and it hurts and you have no money. So suddenly all the other issues become a bigger problem than the pain and you need to undo a lot of that. Mood affects pain, pain affects mood, pain affects sleep, sleep affects mood and affects pain.”
That makes our experience of pain entirely subjective. “We can’t measure it like a thermometer,” says Auckland City Hospital anaesthetist and pain medicine specialist Professor Alan Merry. “Pain is what patients say they have. We tend to ask people to do a single dimensional pain score out of 10, but there are massive differences between types of pain in their character and quality. Also important is the meaning of the pain, and whether it’s associated with an essentially positive experience, such as childbirth, or negative, for example cancer.”
Merry started using spinal cord stimulation in Auckland about 25 years ago, in which an electrode is inserted into the epidural space – the same place where a woman would get an injection during childbirth. The strength of the electrical signal emitted can be adjusted, and sometimes more than one electrode is inserted. The theory is, he says, that the signal gates the pain and stops it going higher. It’s well established to treat patients with sciatica who’ve had unsuccessful back surgery, and is also used for some cases of chronic angina. At up to $40,000 a procedure, however, it’s an expensive solution, and the Accident Compensation Corporation pays for many of the 60-odd procedures performed in Auckland and Christchurch each year. About 30 per cent of pain service clients are on ACC.
Pain management isn’t usually so high-tech. TARPS clinical nurse specialist Kate McCallum, for example, has been using hypnosis in pain management for about 20 years. “Some people might want to go into hypnosis to relax and think about pleasant things; others might specifically focus on changing the pain intensity and there are many ways to do that.”
One is the “switch technique”, in which a patient imagines a panel of light switches with a coloured light bulb above each and a wire from each switch to a different body part. They identify the body part they want to work with, and the wire that goes to that switch. “When you turn off the switch in your imagination and the bulb goes out, in theory the pain goes away for a while or reduces in intensity. Some people can come out of their trance and have less pain or be pain-free for a period of time. In essence, they are giving their pain to their unconscious mind.”
Hypnosis, of course, attracts images of stage-show charlatans making punters cluck like chickens to entertain a crowd, and McCallum doesn’t like to call herself a hypnotist. “It comes with all these connotations – that it’s mysterious, that it’s making people do things they’re not aware of. You get a highly hypnotisable person who’s an extrovert and you put that together, they are probably happy to cluck like chickens. They may well do it without hypnosis as well.”
She says there’s plenty of good science to support the use of hypnosis in pain management and in some ways, it’s akin to what’s happening in the brains of the patients using virtual reality.
“They’ve really left the here-and-now behind and entered this alternative reality, which is what you’re trying to do with hypnosis.”
Patients get about six hour-long sessions, and McCallum would love to see more clinicians using hypnosis to treat patients and teaching them how to use it at home. But, she says, it’s also important patients make the time to use it regularly. “Putting aside 20 to 30 minutes daily sounds good on paper, but people don’t tend to stick to it. They get too busy and put their chores ahead of themselves.”
About 40 per cent of TARPS patients either get back to work, or get partially back to work, after treatment. Back pain is the most common complaint, with limb pain – usually the result of trauma – a close second. Although the success rate for back surgery is between 80 and 90 per cent for the first operation, for a second it’s 60 per cent, dropping to 30 or 40 per cent at a third operation.
He says doctors often feel compelled to intervene, for example with surgery, because the pain is distressing. “Patients say, ‘This is the worst pain in the world, you have to do something, I don’t care what; do anything.’ But the only reason to do anything is if there is a reasonable prospect it will help.
“Sometimes pain is a warning… it stops you doing something that will cause you harm,” says Merry. “But chronic pain has no value. It’s pain that has gone past being useful. You’ve got to know the difference, and the thing we’ve made the biggest progress on is understanding the behavioural components of pain and how to stop over-treating people.”
He says Seattle psychologist Bill Fordyce, a pioneer in the clinical psychology of chronic pain, argued that “people with something better to do, don’t get chronic pain”.
“That’s harsh and not entirely true,” says Merry. “People do get chronic pain, whether they have something better to do or not. But how they function with that pain varies hugely and a lot of what we do at the pain clinic is to try to help them function better, rather than always treat the pain.”
A complex disorder
Up to a quarter of pain clinic patients have complex regional pain syndrome (CRPS), which can develop after a traumatic injury. There are two types, classified according to the presence or absence of nerve damage. Its incidence in the community isn’t known, but the Auckland Regional Pain Service sees about six new patients a month with the condition.
Common features include prolonged pain and sensitivity in the surrounding area, or side of the body. It can cause changes in skin texture, abnormal sweating and co-ordination and balance issues.
Researchers aren’t sure what causes some people to develop it and others not, but suspect a genetic component. It’s rare in the elderly and more common in women.
Auckland Regional Pain Service clinical nurse specialist Kate McCallum has been using hypnosis to help manage pain for about 20 years and says there’s plenty of good science to support its use.
This was published in the November 2017 issue of North & South.