More than 50 percent of individuals with MS identify pain as a significant symptom. For many years, the medical community did not support the idea that pain could be caused by the effects of MS, but physicians today recognize that pain is a common symptom.
MS pain is mixed and may be divided into two different types. Pain from MS can be a direct result of damage to the nerves (referred to as “axons”) of the central nervous system (CNS), which consists of the brain and spinal cord. This first type of pain is referred to as neurogenic, and is caused by a lesion in the CNS. This type of pain may be intermittent or steady; spontaneous or evoked.
A second type of pain is associated with living with disability and its effects. This is referred to as nociceptive. Caused by any mechanism that stimulates a pain response, it can be mechanical, thermal, chemical, or electrical. Examples of this type of pain include musculoskeletal pain, lower-back pain, painful spasms, pain related to urinary-tract infection, pain of pressure sores, and even pain associated with disease-modifying drugs.
This type of pain lies within the axons (nerves) of the CNS that are either inflamed or are malfunctioning after the protective layer of myelin has been damaged. Nerve impulses may go off-track and spread to adjacent damaged nerve fibers, or nerve cells may become over stimulated and misfire. This type of “nerve excitability” is irritating to the nerve cells within the brain and spinal cord, often causing sudden and sharp pain. The sensation can be lightning-like and intermittent, or it can be a burning, tingling, or a tight, “hug-like” feeling that can be continuous.
Surveys for patient pain indicate that the most common pain syndromes experienced in MS are: continuous burning in extremities; headache; back pain; and painful tonic spasms.
Examples of continuous MS pain syndromes include:
- Steady dysesthetic pain, which is a burning, tingling, or tightening sensation, usually occurring in the legs and arms, but sometimes in the body; it is the most common chronic pain syndrome; it can be dull, nagging, or have a prickling sensation associated with warmth; it tends to be worse at night and after exercise; it is also aggravated by changes in temperature
- Severe spasms and spasticity (muscle tightness caused by impaired nerve impulses)
Examples of intermittent MS pain syndromes include:
- Chronic headaches, experienced by up to one-third of patients; more than half (54 percent) report headaches as a symptom at the time of diagnosis; migraines are three-times more common in MS than in the general population; headaches are not associated with disability or lesion burden
- Lhermitte’s sign, a shock-like sensation down the spine and legs when the neck is flexed; approximately 40 percent of individuals with MS experience this type of pain, although it usually does not require any treatment
- Optic neuritis, causing shooting pains in the eye
- Trigeminal neuralgia, a sharp facial pain brought on by a light touch or movement (occurring in roughly 2-to-5 percent of individuals with MS); up to one-third of these episodes can be bilateral (occurring on both sides of the face)
Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen usually won’t work well on this type of pain. The over-stimulated nerves need to be calmed, and this may best be accomplished with anti-epileptic drugs, tricyclic antidepressants, and antispasticity drugs, to treat painful spasticity and spasms. Topical medications such as lidocaine gel or Zostrix® (capsaicin topical analgesic) may help reduce the burning and tingling. Optic neuritis is often treated with steroids to reduce the inflammation of the optic nerve. Non-pharmaceutical strategies may help to reduce the perceived severity of the pain. More information about specific treatments is provided later in this section.
This type of pain is usually less intense but can be long-lasting. For instance, weakness on one side of the body will cause someone to favor the other side and develop stiff joints; muscles can become twisted and cause the body to be unbalanced, frequently leading to muscle and joint pain. The same is true for spasticity (muscle stiffness) and spasms, as well as poor posture, with pain often occurring in the lower back. Even medications can sometimes cause painful side effects such as injection-site reactions, steroid-induced osteoporosis, and degenerative joint disease.
Unlike neuropathic pain, neuromuscular pain can respond to analgesics, such as Ibuprofen.