Pain is a common symptom that affects people of all walks of life. It can be acute (sudden) or chronic (lasting more than three months). Pain can be a warning signal that you are injured, or it may result from miscommunication between the brain and body. Intensity of pain can range from mild to severe, and treatment of pain depends upon its origin.
Common types of pain include nociceptive pain and neurogenic pain:
- Nociceptive pain is caused by activation of nerve receptors that transmit information about trauma or injury to the brain. Nociceptive pain can be somatic (involving the body surface or musculoskeletal system) or visceral (involving internal organs). Examples of somatic pain include joint and muscle pain, pain due to excessive activity or trauma, or pain due to inflammation, spasticity, or paralysis. Visceral pain originates from pain receptors within the chest, abdomen, or pelvic areas. It is often vague and might be described as pressure-like, deep squeezing, dull, or diffuse.
- Neurogenic pain, also called neuropathic pain or central pain, is caused by lesions, injury, or disease of the central or peripheral nervous systems. Examples of neurogenic pain include paresthesia (e.g., numbness, tingling, burning, itching), dysesthesia (e.g., abnormal sensations or distortion of touch), trigeminal neuralgia (i.e., pain affecting nerves of the face), and optic neuritis. Neuropathic pain may originate from lesions in the central nervous system or result from compressed nerves (as in carpal tunnel syndrome). Pain resulting from lesions in the spinal cord might be felt elsewhere (e.g., at the surface of the skin, on the torso, or in the limbs).
Pain in multiple sclerosis
Pain is a common symptom that affects up to two-thirds of people with multiple sclerosis (MS), according to the Multiple Sclerosis International Federation (MSIF). Pain in MS can be paroxysmal (a sudden or recurrent intensification of symptoms) or may become chronic. When pain becomes insidious, it can impact quality of life and one’s mood.
Most common types of pain in MS include:
- Neuropathic pain, including pins and needles, burning, itching, stabbing, numbness, tingling, aching, throbbing, heightened sensitivity to touch, abnormal sensations, girdling (as in the MS hug), or headache
- Musculoskeletal pain, related to muscular weakness or fatigue, spasticity, stiffness, joint pain, back pain, or poor posture
- Paroxysmal pains, such as trigeminal neuralgia or tonic spasms
- L’Hermittes sign, described as an electric-shock-like sensation traveling down the spine and into the limbs when the neck is bent toward the chest
- Optic neuritis, a common first symptom of MS, causing pain felt behind the eye that is made worse with eye movement
Why do my legs hurt?
People living with MS can experience different types of pain in the limbs (legs or arms), the most common of which are neuropathic or musculoskeletal in origin. Neuropathic pain in MS is frequently caused by lesions in the spinal cord and is characterized by sensory changes. Spinal cord lesions may also cause muscle weakness, spasticity, ataxia, or other gait disturbances, each of which can lead to musculoskeletal problems.
Do you experience burning, itching, numbness, tingling, stabbing, or the sensation of bug bites in your legs? These are examples of paresthesia, a form of neuropathic pain, and are often experienced by people with MS. A particularly strange sensation is the feeling of water dripping on or down the leg, which is an example of dysesthesia. Other dysesthesias involve the abnormal interpretation of sensation, hypersensitivity to touch, or a tight banding sensation.
Neuropathic pain and sensory changes are often treated with anti-seizure medications, such as gabapentin, pregabalin, carbamazepine, tizanidine, or clonazepam, and certain antidepressants.
For me, spasticity is a significant source of musculoskeletal pain in the legs. Other causes of MS-related musculoskeletal pain include poor posture, inefficient walking (gait), physical inactivity, muscle deconditioning (being out of shape), and muscle fatigue or weakness.
Exercise, physical therapy, and relaxation techniques can help to address musculoskeletal pain. While “normal” aches and pains may respond to treatment with moist heat, ice, and rest, analgesics, or anti-inflammatory medications, spasticity is often treated with baclofen, diazepam, gentle stretching, and exercise.
Seek treatment for leg pain
While MS can certainly be the source of many different types of pain in the legs, it is not the only possible cause of pain. Other causes of leg pain include blood clots, varicose veins, poor circulation, physical injury or infection, or back pain.
A rare, but extremely painful, condition that can be related to corticosteroid treatment is osteonecrosis, also called avascular necrosis. In osteonecrosis, blood flow to the bones or joints is reduced and the bones begin to die away and break down. Bones literally begin to crumble. Unfortunately, symptoms of osteonecrosis might be attributed to MS, which can delay diagnosis.
If you experience pain in the legs, please discuss your symptoms with your doctor.
“MS Pain.” Multiple Sclerosis International Federation. Web. Accessed at Feb. 17, 2017 https://www.msif.org/about-ms/symptoms-of-ms/pain/
Sahraian MA, Yadegari S, Azarpajouh R, Forughipour M. Avascular necrosis of the femoral head in multiple sclerosis: report of five patients. Neurol Sci. 2012;33(6):1443-6. doi: 10.1007/s10072-011-0914-8. Epub 2011 Dec 31.