This transcript has been edited for clarity.
Corey C. Ford, MD, PhD, MSCS: Hello. My name is Dr Corey Ford, and I am a professor of neurology at the University of New Mexico Health Sciences Center, where I am director of the multiple sclerosis (MS) specialty clinic.
It's my pleasure to introduce Hossein Mousavi, a neurologist who is fellowship trained in MS and neuroimmunology and is currently completing a pain fellowship at the University of New Mexico. [Editor’s Note: Dr Mousavi has completed his fellowship since this was recorded.]
In this discussion, Dr Mousavi will help clarify issues of pain management in MS and management strategies.
Hossein Mousavi, MD: Thank you so much for the introduction.
Ford: Maybe you can start off by telling us about chronic pain in MS and why it's such an important symptom.
Mousavi: MS affects about a million patients in the United States, and about 75% of patients with MS experience chronic pain at some point in their life. Pain is often more refractory as the disease progresses. Pain prevalence also increases as the condition progresses and in patients with spinal cord lesions.
Pain is more prevalent in patients with higher disability, and it can be frustrating in a number of patients with MS. One reason for that is that there are different pain types that patients with MS can present with.
Ford: Are you saying that there are different types of pain in MS and that patients might benefit from different management approaches with each of those types of pain?
Mousavi: Yes. There are different types of pain in patients with MS. We usually divide chronic pain into three categories: nociceptive pain, nociplastic pain, and neuropathic pain. Nociceptive pain is usually caused by activation of nociceptors in the periphery owing to actual or threatened tissue injury. This type of pain is prevalent in patients with MS. About 40% of people with MS who have pain have nociceptive pain.
Nociplastic pain arises from the altered nociception despite no clear evidence of injury. This type of pain is also prevalent in more than 20% of patients. The third one is neuropathic pain. This type of pain is usually caused by a lesion or a disease in the somatosensory nervous system. About 10% of patients with MS present with this type of pain. There's a large number of patients with MS who can have a mixture of all three pain syndromes.
Ford: Let's take an example of a patient who has MS. They appear stable on their current disease-modifying drug, yet they're coming to clinic with worsening pain. How would you approach their treatment?
Mousavi: Unfortunately, there is no easy answer for this question. Despite the advancement of understanding of MS and disease progression, pain management in this population is often suboptimal. However, there are steps that can be taken.
First, we need to understand what type of pain a patient with MS is having. One way to understand that is to utilize questionnaires that are available for the study of chronic pain. For instance, there is a questionnaire for neuropathic pain called painDETECT that is frequently used. There are also questionnaires for nociplastic pain, and the one that we often use is the Fibromyalgia Survey Questionnaire.
Once we understand what type of pain the patient is having, then we can start to go on to treatment. Pain management in patients with MS often starts with pharmacotherapy. Although physical therapy has an important role in pain management in general, it is not often utilized in patients with MS for the purpose of pain management.
The pharmacotherapy that we often use also depends on what type of pain the patient has. For neuropathic pain, there are multiple choices. We know you can start with tricyclic antidepressants (TCAs), serotonin–norepinephrine reuptake inhibitors (SNRIs), such as duloxetine, and gabapentinoids. If patients are refractory, we can suggest a capsaicin patch or a medication like tramadol.
For nociplastic pain, similar medications can be used, except for tramadol. However, ketamine infusion is one of the medications that has shown significant benefits for this type of pain syndrome. The third one is nociceptive pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often the first-line therapy, and agents such as baclofen and tizanidine, which we often utilize for the management of spasticity, can be helpful for this population.
One thing I want to emphasize, that I think is very important, is the utilization of physical therapy in the management of pain in this population. For instance, if a patient has diffused chronic pain, low aerobic exercise can be used and often is beneficial. If the patient has deconditioning, strengthening and stretching exercises can be helpful. Balance therapy for people who have weakness related to pain not only can help patients with pain but can also help MS patients with balance problems.
Ford: Interesting. You stated that some patients might not have a satisfying response to some of these interventions. What would you do when a patient has tried different medications and is not tolerating them, having side effects, or is refractory to them?
Mousavi: Unfortunately, this is a common clinical scenario in patients with MS and chronic pain. For example, patients with MS who have trigeminal neuralgia often respond to medications such as carbamazepine.
However, what we see over time is that people's tolerance for the medication decreases because the dose of the carbamazepine, or whatever medication they are on, needs to be increased in order to continue to be effective, and patients either become refractory to the pain management drug or, because of the side effects of the medication, they cannot tolerate the medication. This is often associated with worsening of other comorbidities of MS, such as cognitive issues, balance problems, and falls.
In such cases, nonpharmacotherapy approaches can be considered. For example, for people with neuropathic pain, there are multiple interventions that can be used, such as epidural steroid injections, depending on where the pain is. A spinal-cord stimulator is one approved procedure for patients with neuropathic pain. Peripheral nerve stimulators and intrathecal baclofen drug delivery can also be used for selected patients. Cognitive-behavioral therapy (CBT) and hypnotherapy are important treatments that we should not forget in this population with neuropathic pain.
For nociplastic pain, I think patient education is very important. Also, treatment of comorbidities — primarily mental comorbidities — of patients with nociplastic pain is important because this type of pain comes with psychological comorbidities; patients would benefit from CBT, hypnotherapy, and things of that nature.
For nociceptive pain, radiofrequency ablation often can be used, depending on where the pain is. It could be used in the back or in the knee. There are other forms of surgical treatment for this population. One example would be for people with spasticity who are refractory to oral baclofen. Sometimes we can use intrathecal baclofen therapy for this population.
Ford: Dr Mousavi, that's some very important and useful information for practitioners dealing with people with MS. What do you think the future holds for pain management in MS?
Mousavi: Currently, in pain medicine, we lack specific disease-modifying therapy for management of chronic pain. We are fortunate in the MS world that we have so many disease-modifying therapies and some in the pipeline. It is very interesting to me that development of chronic pain is related to dysregulation of the immune system.
Several of our disease-modifying therapies for the management of MS have shown to be helpful in animal models of chronic pain. Whether these medications, in the future, can be tested in patients with MS, whether they have pain or not, would lead us to more personalized treatments and would be a major achievement for not only patients with MS, but also patients with chronic pain who require disease-modifying therapies.
Ford: Thank you, Dr Mousavi, for your insights into this very large problem of pain, and the types of pain, in people with MS. We appreciate your time and expertise.
Mousavi: Thank you so much.
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Cite this: Pain Relief in MS: Expert Tips and Strategies - Medscape - Jul 17, 2024.
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