"Neuromodulation wraps back pain in a warm blanket"

Desperate patients: neurosurgeon Prof. Maarten Moens sees many of them in his consultations. "I hear it regularly: 'Doctor, do something, anything, or I'll jump off the bridge'. Severe chronic back pain is a terrible situation. You sleep poorly, you can no longer work, you're in a bad mood, your relationship and family life are under pressure... It has an impact on all aspects of life. Not knowing whether it will ever stop makes the situation completely hopeless. People really feel trapped in their own bodies."

Who is eligible for neuromodulation?
Maarten Moens: "Neuromodulation is expensive – expect to pay around 20,000 euros. The RIZIV (National Institute for Health and Disability Insurance) only reimburses the procedure for people who have had surgery on their neck or back but still experience pain. The hopeless cases, so to speak. Every year, 700 to 750 patients in Belgium are eligible."

What is the problem for these people?
Maarten Moens: "Often there has been a real pain problem at some point and the nerves have been damaged, but there is no longer any sign of this. Nevertheless, these people suffer greatly. They experience burning pain or sudden shocks, or feel as if ants are crawling through their bodies. It is false information that travels from a leg, arm or neck to the brain via the nerves. I explain to people that it is in their heads, but literally so."

What does neuromodulation do?
Maarten Moens: "Neuromodulation suppresses the incorrect information at the level of the back or neck, so that it no longer reaches the brain."

What does the procedure look like?
Maarten Moens: We insert an electrode, a fine electrical wire, into the epidural space, on the thick protective membrane surrounding the spinal cord and nerves. This is done under local anaesthetic, so that the patient can tell us whether we are in the right place. The electrode is connected to a small battery that sends pulses to the electrode. For the first three weeks, this is an external battery. If the stimulation proves effective, the battery is permanently implanted, usually above the buttock, but it can also be placed next to the navel or under the collarbone.

It sounds simple.
Maarten Moens: "It has been very simple for a long time. Neuromodulation has been around since the 1980s. For decades, the same electrical pulse was used. That has changed completely in the last ten years. People have started experimenting with new 'paradigms'. By playing with different frequencies, pulses and curves, with more or less current and current blocks, we can suppress the pain even better. That was a turning point. Now people don't even feel that tingling sensation anymore.”

How many patients benefit from this?
Prof. Lisa Goudman (statistician): "The trial period with the temporary battery lasts three weeks. After that, 90 to 95 percent feel so much better that a permanent battery can be implanted. That is a very high figure, especially considering that this is a difficult and heterogeneous target group. In the longer term, the success rate drops slightly, but that is mainly because people forget how bad the pain was. If the surgeon stops the electrode for a moment, the pain immediately returns unfiltered. The problem is also psychological: you don't really heal. Neuromodulation is purely symptom suppression.”

How do you measure whether neuromodulation is working?
Lisa Goudman: "Usually, only the pain experience is assessed after the three-week trial period. For the past few years, we have been taking a broader view, based on four parameters. Is the intensity of the pain decreasing? Has sleep quality improved? Is the patient more active? And can pain medication be reduced by at least half? We advocate looking at the evolution of overall quality of life, including in the longer term. We put forward this holistic approach at Stimulus five years ago. It has received a lot of positive international feedback."

What is this holistic view based on?
Lisa Goudman: "On conversations with patients. They told us that they wanted to be happy again. When we asked further questions, participation emerged as the key word. People wanted to be able to work again, do their own shopping, see their family, meet up with friends. The crucial activity in all these wishes is walking. Those who can do that are able to participate in society.”

Are you already applying this new approach in clinical care?
Lisa Goudman: "Not yet. Currently, people receive a neuromodulator and are then often left to their own devices. In the Opera research project, we are currently looking at how we can improve the post-treatment process for patients, using a multidisciplinary approach. For example, a psychologist explains how to cope with days when the pain is worse, a physiotherapist provides cardio training and exercises to improve the stability of the abdominal and back muscles, an occupational therapist advises people with ergonomically demanding jobs, and a dietician gives nutritional advice."

What is your view on pain medication? Back patients often take strong opiates.
Maarten Moens: "According to international guidelines, opiates should really only be prescribed for cancer. There is the problem of habituation: the patient needs more and more to suppress the pain. There is also a high risk of addiction or overdose. Nevertheless, they are frequently prescribed in good faith because nerve pain is so severe. Almost everyone who is eligible for neuromodulation is taking opiates at that point. We realise that this pain medication interferes with neuromodulation. For example, you adjust the neuromodulation to the pain level with opiates, while the patient will subsequently reduce their intake. It is almost impossible to stop completely. Withdrawal from opiates is very difficult, and the risk of relapse is high. Patients who succeed say they never want to go through it again."

What research are you planning with the new FWO funds?
Maarten Moens: "Among other things, we are going to conduct research into the use of pain pumps in a home setting, so that patients do not have to go to hospital to have the pump refilled. Administering pain medication via such a pump, directly into the problem area, is also a form of neuromodulation. We receive funding from the Belgian Cancer Foundation for similar research, but for the treatment of oncological pain. The pain pump is reimbursed worldwide for cancer pain, except in Belgium. We don't understand why. Hopefully, this research will be a stepping stone to a reimbursement scheme."