For many years, MS was considered a “painless disease”. However, it is now recognized that more than 50% of people with MS will experience some type of pain.
For people with MS, the consequences of pain can have a severe impact on quality of life. Pain may contribute to sleep disturbance, leading to fatigue and depression. It can prevent you from going to work or school, and having an engaging social life. Most unfair of all, pain is a self-perpetuating condition: the more pain we experience, the lower our pain threshold (or ability to tolerate pain) becomes.
The good news is that most MS-associated pain can be prevented, eliminated or improved through a variety of management strategies and newer therapies.
What’s the point of pain?
Pain is actually a positive, protective mechanism. It alerts us to potential bodily harm when we touch something hot or sharp: it’s through pain, we learn to avoid things that may be dangerous. Pain also helps us to heal. When injured joints and muscles ache, we take care to use the injured area gently so that it can recover. During illness, pain forces us to rest, which allows our bodies to mount an immune response and ﬁght disease.
However, in many cases, pain (particularly drawn-out, chronic pain) serves no useful function and only compromises quality of life. Unless it resolves on its own, this pain should be treated.
How pain is treated depends on the type of pain it is. Pain is characterized by its origin (where it comes from) and duration (how long it lasts).
- Nociceptive Pain is pain that results from tissue damage. Pain receptors in the tissues, called the nociceptors, send electrical impulses to the brain signaling pain messages.
- Neuropathic Pain is not caused by tissue damage. It occurs due to damage or faulty connections within the nervous system. This distorts messages to the brain and may cause the brain to interpret signals as pain messages even when there’s no injury. Neuropathic pain occurs in various disease states, including MS, and often becomes more intense as the underlying condition deteriorates, sometimes resulting in disability.
- Neuropathic Pain in MS. Pain signals are carried throughout the body to the brain via nerve cells, which make up the nervous system. Think of the signals as an electrical current travelling through a circuit. If the circuit is damaged, the signals cannot get through. MS attacks myelin, a protective sheath covering your nerve cells. The more your myelin is damaged, the more difficult it is for the signals to get through. Sometimes signals become distorted by the poor transmission and your brain receives them as pain.
- Acute Pain. Short-term, often intense pain, usually associated with tissue damage such as a burn, cut or blow. Acute pain is often self-limiting; it gets better by itself and goes away when healing occurs. In most cases, it will respond to simple painkillers such as acetaminophen or ibuprofen.
- Chronic Pain. Persistent, long-lasting pain which may be caused by a chronic condition such as arthritis or cancer, or which may not have an obvious cause. Chronic pain may continue for weeks or months, long after any possible healing has occurred. The pain intensity may vary, but for many, the pain seems always to be there. Chronic pain usually doesn’t respond to the same treatments used to relieve acute pain.
Types of pain in MS
Pain in MS may be caused directly by the disease acting on your nervous system or indirectly, following decline in function. The two main types of pain (acute and chronic) have been reported by people with MS. Each type is associated with a variety of different nociceptive and neuropathic syndromes which may vary in intensity and duration.
Acute MS Pain – Paroxysmal, spasmodic episodes
- Trigeminal Neuralgia (TN). An extremely painful nervous disorder in which gentle stimulation of the face or mouth results in a stabbing, electric shock-like pain; simple activities like tooth-brushing, washing, shaving or even a cold wind can bring on an attack. Pain usually lasts for a few seconds, but several attacks may occur in succession giving an impression of persistent pain. Symptoms may affect lips, eyes, nose, scalp, forehead and jaws. TN affects up to 7% of people with MS.
- Muscle Spasm and Spasticity. An involuntary muscle contraction that is not co-ordinated with other muscles. Painful tonic spasm (PTS) is an extreme form of spasticity seen in 1 in 10 people with MS. The muscle suddenly contracts causing a violent and painful extension or ﬂexion of the limb. It feels like an extreme cramp.
- L’hermitte’s Sign. Electric sensations (and sensations of light) that feel like a surge of pins and needles down the back and neck. They are caused by a discharge of partially demyelinated neurons brought on when the neck is ﬂexed forward.
Chronic MS Pain
- Musculoskeletal Pain. Caused by abnormal stresses on joints, muscles and ligaments. It is often a result of muscle weakness. Low back pain is a particularly common MS-associated pain, caused by poor posture or wheelchair use. Musculoskeletal pain often responds to traditional painkillers.
- Chronic Neurogenic Pain (Dysaesthesia). A continuous burning, aching or prickling sensation, typically persistent in the extremities and usually worst in the legs. This appears to be a direct result of MS disrupting the central nervous system.
- Allodynia. Hypersensitivity to touch. A painful response to normally non-painful things such as stroking with a soft brush, getting dressed, or going out in the wind.
- Optic neuritis. Pain experienced when the eye is moved. Optic neuritis is often a ﬁrst symptom of MS.
Pain Management Strategies
The management of pain in MS over time will require a multidisciplinary team. These individuals may include your nurse, neurologist, pain specialist, psychiatrist, occupational and physiotherapist, psychologist, as well as practitioners of alternative and complementary medicines.
Identiﬁcation and characterization of pain is the ﬁrst step toward relieving it. Pain is a subjective experience and may be difﬁcult for you to describe and practitioners to assess. Fortunately there are a number of tools available to evaluate pain more precisely, helping to direct your physician to the most appropriate therapy.
There are a number of different treatment options for pain in MS. The choice of treatment depends largely on the nature of the pain itself, rather than the exact underlying cause.
If possible, a single drug is used to avoid the drug interactions and additional side effects of multiple drugs. Alternative therapies may be combined with pharmacologic agents for maximum beneﬁt. Finally, it is important that any co-existing depression be treated; untreated or inadequately treated depression can increase your perception of pain intensity.
Because the selection of therapeutic options involves a variety of sources—prescription drugs, over-the-counter medications, and alternative and complementary products and therapies—it is essential that you be fully informed by the appropriate health care professional and practitioner as to why they are recommending a treatment option. At the same time, it is very important to fully inform your healthcare professionals and practitioners as to what other therapeutic options you may be using to manage pain in order to avoid complications that can sometimes result from multiple drugs and treatments.
Non-pharmacological pain relief
Acupuncture. Traditional Chinese medicine involving the insertion of extremely ﬁne needles into precise nerve stimulation points in the skin and muscle. It is thought to work by increasing the body’s release of natural painkillers, endorphin and serotonin, in the pain pathways of the spinal cord and brain.
Transcutaneous Electrical Nerve Stimulation (TENS). Using the same principle as acupuncture, TENS uses an electrode on the skin to produce a weak current to stimulate a painful muscle or skin. The current causes endorphins to be released into the cerebrospinal ﬂuid. TENS appears particularly effective in relieving radiating deep muscle pain.
Exercise can be very helpful to prevent and treat pain from musculoskeletal causes. A regular stretching program can help the discomfort from spasticity. Optimizing weight and core strength can help prevent and treat back, neck and joint pain. Exercise has been shown to help pain from many different conditions, partly through the enhanced release of the body’s own pain-relieving chemicals.
Massage stimulates blood ﬂow around the body, which may promote relaxation and pain relief. However, it may also send muscles into spasm, so should be used with caution.
Pharmacological pain relief
There are many medications that your doctor can prescribe to treat your pain. All medication must only be used under professional supervision. Members of your healthcare team will be pleased to discuss these therapies with you in greater detail.