Medicine & Research

RX Update - Multiple Sclerosis and Pain

By Ellen Whipple, Pharm.D.
Historically speaking, pain was not always thought to be a symptom of multiple sclerosis. Over time, clinicians have come to realize that it is not only an MS symptom, but also in some cases, a key symptom. Data suggests that 25-60 percent of people with MS experience pain, and that, as a symptom, pain is frequently underdiagnosed and undertreated. One survey found that 38 percent of patients who reported MS-related pain actually received treatment for their symptoms, and only 39 percent of patients said that their pain was adequately controlled.
Certain factors, such as age at onset, length of time with MS, or degree of disability, do not distinguish between those with pain, and those without. Because pain can affect activities of daily living, such as work, recreation, mood, and enjoyment of life, it is important that patients who experience pain report it to their physicians.
Why does pain occur in MS?
MS-related pain varies from patient to patient. “Chronic and achy” pain is commonly the result of fatigued muscles, especially when they are compensating for muscles that have been weakened from the MS disease process. “Electrical and stabbing” pain occurs from faulty nerve signals emanating from the nerves due to MS lesions in the brain and spinal cord.
What are the Common Types of Pain? And How Do Their Treatments Vary?
Musculoskeletal pain occurs in approximately 20 percent of patients with MS. It is because of muscular weakness, spasticity, and imbalance. It is most often seen in the hips, legs, and arms, especially when muscles, tendons, and ligaments remain immobile for extended periods of time. Back pain may occur because of improper seating or incorrect posture while walking. Contractures associated with weakness and spasticity can be painful. Muscular spasms or cramps (called flexor spasms) can be severe and discomfiting. Leg spasms, for example, often occur during sleep.
The treatments of musculoskeletal pain vary depending on the cause. Nonsteroidal anti-inflammatory drugs and traditional pain medications can be used to treat musculo-skeletal pain. When the pain is related to spasticity, antispasmodic medications can also be useful. Sometimes assistive devices can help with musculoskeletal pain when the pain is because of improper seating or incorrect posture.
Sensory or paroxysmal pain occurs in 5 to 10 percent of MS patients. This type of pain is the result of demyelinating lesions. Symptoms are characterized by brief, almost stereotypic, events occurring frequently and often triggered by movement or sensory stimuli. In many instances they are caused by the faulty transmission of nerve impulses at sites of previous disease activity. While paroxysomal pain is annoying, it does not represent an exacerbation.
Trigeminal neuralgia and Lhermitte’s sign are two of the most common types of paroxysmal pain syndromes. Trigeminal neuralgia affects the trigeminal nerve, which carries sensation from the face to the brain. Even mild stimulation of your face, such as brushing teeth or putting on makeup, can trigger a jolt of excruciating pain. Trigeminal neuralgia can progress and cause longer, more-frequent bouts of searing pain. Lhermitte’s sign is indicated by a stabbing, electric-shock-like sensation running from the back of the head and down the spine, which is brought on by bending the neck forward.
These paroxysmal attacks typically respond to low doses of anticonvulsant medications, such as carbamazepine and valproic acid, and usually remit after several weeks or months. Soft collars are often used in patients who experience Lhermitte’s sign.
Neuropathic pain is probably the most commonly reported pain syndrome among people with MS. It often is the result of nerve damage caused by MS lesions. The effect of nerve damage is a change in nerve function both at the site of the injury and areas around it. Approximately 50 percent of MS patients who report pain experience neuropathic pain. This type of pain is often described as a shooting or burning pain. While neuropathic pain can go away on its own, it is often chronic. In many cases neuropathic pain can be unrelenting and severe; in other instances, it comes and goes.
Neuropathic pain can be very difficult to treat. Anticonvulsants, antidepressants, antispasmodics, capsaicin cream, and cannabinoids are all viable treatment options. Patients often have to try different combinations of products to find the one that works best for them. Opioid pain medications do not
generally offer patients with neuropathic pain much relief. 
No two patients with MS show symptoms in the exact same way, and the same can be said for MS-related pain. There are different types of pain and different types of treatments. All patients with multiple sclerosis should discuss pain with their physicians at each visit. Patients should particularly make their physicians aware if pain changes or if new pain occurs.