Pain Management |
From “Charting a New Course: The Guide to Independent Living After Spinal Cord Injury
Courtesy of The University of Michigan Model Spinal Cord Injury Care System
Chronic pain after SCI affects one in three people. Based on a variety of studies, people with SCI report they have pain about 64-80% of the time. Pain can have serious effects on people’s mood and quality of life in addition to limiting their activities.
The severity of pain seems to be associated with the completeness of the injury but not the level of injury. Forty seven percent of people with SCI in one study reported the onset of chronic pain within the first year after their injury. Many people are dissatisfied with current treatment efforts and at least 19% in one study and 39% in another reported experiencing severe pain.
Chronic pain can result in psychological issues as well. This does not mean that it is “all in your head,” just that your physical and very real pain is causing mental and emotional stress as well. The pain can also be magnified by other personal factors, including depression or unemployment.
Understanding the source of the pain can enable you and a health provider to find effective ways to treat and deal with pain. There may be some pain that can be reduced and managed, but not completely eliminated.
The Anatomy of Pain
Pain occurs, for instance, when the skin is irritated by all sorts of stimuli, such as a burn or a cut. Receptors in the skin transmit a signal to nerve cells (called neurons), which move along the nerves away from the source of the stimulus. The nerve cells transmit a message to the spinal cord and up to the brain, which translates the message. If the brain interprets the stimulus as pain, then it can initiate a response, such as sending a signal via a motor nerve to cause movement, such as pulling away from a painful stimulus.
Pain after Spinal Cord Injury
After an SCI, some nerve pathways are disconnected. There may be damage to sensory nerves in the spinal cord that results in abnormal processing of a stimulus. This results in decreased or absent sensation, numbness, or tingling. The pain may not be sensed in the area where it would usually be felt. Or, pain occurs without a stimulus that would usually cause pain. Sometimes, pain is generated from damaged nerves or nerve roots. This type of pain is called neuropathic pain and can be further classified by the area where it feels painful.
Pain is due to activation of pain nerve fibers at some level of the neural axis. Pain can be acute or chronic. Acute pain has a specific cause, such as an injury or a disease. Once the medical condition is treated and the area heals, the pain ends. Immediately after and SCI there may be pain from the original injury with gunshot wounds tending to create more pain than other types of injuries.
Chronic pain is pain that occurs over long periods of time. The cause of the pain may be unknown and the pain can come and go. There are basically two types, nociceptive and neuropathic pain. Nociceptive pain is sometimes thought of as “normal” pain, as it is due to actual tissue damage, like a bruise or cut. The nerves are working normally, signaling that something is wrong in an area of the body. With neuropathic pain there is not an identifiable problem in the area of the pain due to abnormal processing of sensory input from the original SCI.
Types of Neuropathic Pain
In general, neuropathic pain with SCI can be defined into five different types. Classifying it can make understanding the cause easier, treatment more specific and, hopefully, more successful.
- Central Pain is discomfort felt below the level of injury. This can include numbness, pins and needles, burning and other types of pain. Central pain can be difficult to treat, and can range in severity from annoying to limiting everyday functions.
- Root Pain is caused by compression of the nerve roots and is experienced at the injury level. Some people feel this as pain radiating around the body. Root pain may have a pattern of waves and can change in intensity over time.
- Sympathetic Pain takes place in areas where you don’t have normal sensation. This is pain associated with abnormalities in sympathetic activity seen as swelling, coolness, warmness, redness or blue discoloration, localized tenderness, and skin changes.
- Nerve Compression Pain is seen at or above the level of injury. This includes nerve root compression from disc disease, nerve entrapment like carpal tunnel syndrome, and syrinx, which is a rare condition that affects about 2% of people with SCI. A fluid-filled cavity, called a “syrinx” forms in the spinal cord, sometimes years after the initial injury. The symptoms may include pain and loss of nerve function, although some people with a small syrinx may never know they have one. An MRI or CT/myelogram will aid in diagnosing this condition.
- Referred Pain is pain that is sensed in an area away from the source of the problem. One example occurs when an individual has spasticity due to a stimulus in an area of the body without sensation. The pain is “referred” from one are to another.
Pain may also trigger other problems, including autonomic dysreflexia and spasticity. These symptoms should be reviewed when visiting a health provider about pain. These conditions are described elsewhere in this manual.
Upper Extremity Pain is often related to transfers, pressure relief and wheelchair mobility. In one study, upper extremity pain interfered with the ability to transfer 65% of the time. Research has found that most common upper extremity pain problems occur in the shoulders (75%), then the wrists (53%) and less often in the hands and elbows.
Shoulder pain is associated with time elapsed since spinal cord injury, shoulder range of motion limitations, lower overall health and lower function. Strengthening the shoulders and increasing endurance training may help decrease the intensity and frequency of shoulder pain.
Treatment of Pain
Managing chronic pain can be an involved process. It may require a combination of drugs, therapy and other treatments and may take some time to work out. Some of them may involve alternative or psychological methods, such as bio-feedback.
Try to keep an open mind about treatment and be flexible and cooperative. Do tell your doctor about pain and describe it as well as you can. Keep track of when the pain occurs, how it feels (burning, stabbing, tingling, aching, etc.), its intensity, how long it lasts and anything and anything that either worsens or reduces the discomfort. Keeping a diary or writing on a calendar may help chart pain.
Research has shown a person’s other concerns can worsen pain. Stress, anxiety and inactivity can affect pain. Emotional issues, which at first might not seem to play any role in feeling pain, may actually be important. Having few outside activities and interests, being isolated and feeling hopelessness and negative can also reduce your ability to cope with pain.
Medications
- Antiseizure medications: These drugs (including Gabapentin, Carbamazepine, Phenytoin) are used to treat neuropathic and central pain. They also play a role in treating chronic pain. Sometimes anti-seizure drugs are used along with anti-depressants.
- Anitdepressants: Two types of antidepressants, selective serotonin reuptake inhibiters (SSRIs) and tricyclics, are sometimes used to assist treating pain. The reason behind using them is that these drugs can improve pain control, enable a pain medication to work more effectively, and help with sleep.
- Anti-inflammatory drugs: These medications, including aspirin, Motrin, Advil, Ibuprofen and others decrease pain that is caused by inflammation.
- Opiates: Traditional pain medications (such as morphine, codeine) and newer, synthetic narcotics (including oxycodone and levophanol) play a complex role in managing chronic pain. These drugs have the potential for causing dependency and/or may no longer work after a time (an effect known as tolerance), so care must be taken with these medications, although they are very useful for some people. Common side effects include cognitive effects (depression, irritability, and other symptoms) and slowing of the digestive tract causing constipation and other problems and depression of the respiratory system. They typically have very limited use in the treatment of neuropathic pain.
- Marijuana: This drug has received widespread attention in the popular press. Its role in pain management is not clear.
Physical Interventions
- Transcutaneous electrical nerve stimulation (TENS): This treatment involves a high frequency, low intensity nerve stimulation designed to block signals from the areas of nerve damage that are triggering a pain response.
- Dorsal column stimulator: This device is another type of high frequency, low intensity nerve stimulator placed surgically in the body to block neuropathic pain. This approach can be effective for treating a specific nerve injury.
- Intrathecal morphine: A pump is surgically planted under the skin. A catheter runs from the pump device to the spinal canal which delivers morphine to be delivered directly in an area to block pain, avoiding the need for taking morphine by mouth. The advantage is that the drug’s side effects can be avoided.
- Physical therapy: This treatment is especially helpful in those people who have nociceptive pain, although it can be an effective treatment for neuropathic pain as well.
Other Treatments
There are other, alternative treatments for pain that people can investigate, especially if conventional therapy has not been effective. Biofeedback, visualization, massage therapy, and acupuncture are other methods used to help treat and manage pain.
A recent study at the University of Michigan found that a natural, painkilling chemical was produced in the brains of volunteers who believed they were receiving a pain reliever while they were given a painful injection. This suggests that the brain and nervous system’s complex role in perception may provide the key to managing chronic pain.
There are many different strategies to address chronic pain. Try to educate yourself about different options and find methods that work so that pain does not rule your life.
~Anthony Chiodo, M.D.