Electric shocks in the neck that can end chronic pain
SURGERY to treat chronic pain typically involves electrical stimulation of the spinal cord to weaken or block pain signals. A new procedure can stop the pain messages before they even reach the spinal cord, making pain relief more effective. Roland Wessling, 45, a forensic scientist from Oxford, had the treatment, as he tells CAROL DAVIS.
THE PATIENT
FOUR years ago, I developed agonising and constant pain in my right hand, like a severe burning sensation.
I was diagnosed with complex regional pain syndrome, or long-lasting pain. It usually follows an injury — three months earlier, I’d suffered carbon monoxide poisoning and had lain unconscious on my arm all night, damaging the nerves.
I’d been on a camping trip with my partner of four-and-a-half years, Hazel, just after her 30th birthday.
One morning, I woke up feeling incredibly sick and disorientated. Hazel was lying still and I knew she had died. I screamed for help, but no one heard.
It took ages to crawl out of the tent but, eventually, a nearby camper called an ambulance.
We’d been poisoned by carbon monoxide from the barbecue I’d taken into the tent the night before — I was devastated.
I was in intensive care for two weeks, having oxygen therapy to reverse the effects of the poisoning. I’d been unconscious for so long that my arm had swollen to twice its normal size under the pressure of my weight.
I had eight operations over three weeks — to cut open the skin to make room for the swollen muscle and to close the skin once the swelling had subsided.
Then I needed six months of physiotherapy to help get the feeling back in my hand — but as sensation came back, it brought agonising pain.
I was prescribed painkillers, including gabapentin and morphine-based drugs.
These made the pain manageable and I was able to work, but they made me woozy — I could drive short distances but I’d have to pull over midway for a doze.
Two years after my accident, with all other options exhausted, I was offered spinal cord stimulation — where electrodes are implanted close to the spinal cord to fire signals to stop pain messages reaching the brain.
I was referred to John Radcliffe Hospital, in Oxford, where Alex Green, my consultant neurosurgeon, said they were using a new kind of stimulation.
Instead of implanting electrodes in the back near the spinal cord, they would implant them in my neck, in the dorsal root ganglion (DRG), a collection of nerves thought to transport pain signals to the spinal cord and then the brain.
By stimulating the DRG, they could block pain signals coming from my hand.
Mr Green said they’d had good results with this new method because it is more precise and intercepts pain messages before they reach the spinal cord. The electrodes would be connected to a battery under the skin in the fleshy area above my buttocks.
I would be able to control the signals between the battery and the electrodes using a remote control, and so manage my pain.
The operation, in January 2014, lasted an hour. I was woken up once the electrodes were implanted and asked how I felt.
When I said I felt tingling in my fingers, the team cheered, as this meant the correct spot was being stimulated — then they sent me back to sleep while the battery was implanted. I went home the next day.
The stimulator is on continually, but I have to be careful how far I turn it up — if it is all the way up my hand tingles uncomfortably.
This is because, while blocking pain signals from the nerve that causes pain, it also stimulates other nerves in the hand.
The device has taken away that agonising pain. I still take painkillers, but it’s down to 11 from the 27 I took before, and I’m back to work as normal. I can also go out socially again, since I no longer just want to go to bed.
THE SURGEON
ALEX GREEN is a consultant neurosurgeon at John Radcliffe Hospital in Oxford. AROUND 5 to 10 per cent of us have some degree of pain caused by damage to the nerves.
This can happen for a number of reasons, including surgery, amputation or complex regional pain syndrome — severe pain following an injury where nerves are damaged.
Why pain persists for so long is poorly understood. We offer painkillers, which block pain messages to the brain, or nerve blocks, where we inject local anaesthetic or steroids close to the spinal cord to block pain signals.
But 7 to 8 per cent of people with pain caused by damaged nerves have ongoing trouble despite all of these measures and need more drastic treatment.
Spinal cord stimulation has helped thousands of people worldwide. We put an electrode into the space inside the spine that surrounds the spinal cord — the long bundle of nerves that connect the brain to the body — to try to modify the nerves transmitting pain messages to the brain.
But it doesn’t work for everyone, especially people with complex regional pain syndrome.
DRG stimulation was devised in the U.S. ten years ago.
Instead of putting electrodes inside the spine, we put them in the DRG. This blocks signals before they reach the cord, and we can also target the responsible nerve fibres more precisely.
The procedure is available at more than 12 UK centres, and studies show great results — between 81 and 93 per cent of patients report significant reductions in pain, compared with 55 to 72 per cent after spinal cord stimulation.
The Axium Neurostimulator System is the only approved DRG stimulation device, and we make it available to roughly half of our chronic pain patients.
First, I put a needle that is 2.1 mm in diameter into the top of the spinal cord and find the tiny hole in bone where the problematic nerve exits the spine to the DRG.
Then I feed in the wire containing electrodes and create a loop so it will not pull out. I use a plastic clip to anchor it just under the skin.
We wake the patient and check it works by connecting the electrodes to a temporary battery, then put the patient back to sleep and make a 5cm incision to create a pocket for the battery, tunnelling the wires under the skin to connect them.
The battery will probably last five years before it needs changing. We hope that the stimulation will work well in the long-term and give patients like Roland years of targeted pain relief.
ANY DRAWBACKS?
RISKS include a 1 to 2 per cent chance of fluid leaking from the spinal cord, which causes temporary headaches, and a 2 to 3 per cent risk of the leads moving, in which case the procedure would need to be redone, says Mr Green.
There is also a one in 10,000 risk of paralysis — or it might simply not work, he adds.
Dr Vivek Mehta, a consultant in pain medicine at St Bartholomew’s Hospital, London, says: ‘As with any spinal cord stimulation procedure, this carries risks, including a small risk of bleeding during surgery or of nerve damage, which can cause tingling for days or weeks.
‘ But this technique is very exciting because we can actually pinpoint the nerve leading to a specific area and treat pain far more precisely.’
THE operation costs £25,000 to £30,000 privately, and £18,500 to the NHS.