Chronic pain: relieving the burden with medical technology

“I would typically spend two or three days every week in bed and unable to move,” he says. “In three years, I was admitted to the hospital 23 times. I wasn’t able to work because the pain was so bad.”

Pain is a reaction to signals that are transmitted throughout the body. These signals are sent from the pain source, through the nerves in the spinal cord, and up to the brain, where they are perceived as pain. Chronic pain, defined as pain that persists or recurs for more than six months, can be caused by a variety of injuries and diseases, including nerve damage and cancer, and most commonly affects the lower back and legs. Left untreated or under treated, chronic pain may cause significant physical and emotional disability and accounts for considerable direct healthcare costs, and indirect costs such as loss of productivity.

Consider:

• Chronic pain affects approximately 25 percent of the U.S. population and 50 percent of patients with cancer
• Almost three-fifths of adults 65 and older with pain in the United States said it had lasted for one year or more
• Nearly 1 in 5 adults in Europe suffers from long-term pain – at least 75 million people
• Chronic pain from arthritis, back problems, headache and other musculoskeletal conditions costs U.S. businesses $61.2 billion a year in lost productivity
  

Two types of chronic pain

There are two types of chronic pain: nociceptive pain and neuropathic pain:

• Nociceptive pain is pain from disease or tissue damage outside the nervous system, and is dull, aching, throbbing and sometimes sharp. Examples include bone pain, tissue injury pressure pain and cancer pain.
• Neuropathic pain is caused by damage to the nervous system, and is burning, tingling, shooting or lightning-like pain. Compared to nociceptive pain, neuropathic pain is more severe, more likely to be chronic, and less responsive to analgesic drugs and other conventional medical management.

The most common location of neuropathic pain is in the back and legs.

• Low back pain is the most common type of pain reported in the United States, with 23.9 percent of people ages 18 to 44 and 30.4 percent of people age 65 and over suffering from this condition in 2004.
• In 2004, 12.4 percent of Americans ages 18 to 44 and 14.4 percent of Americans age 65 and over suffered from neck pain.

A quality of life issue

Chronic pain can severely detract from victims’ quality of life. Between half and two-thirds of people with chronic pain in a European study reported that they were less able to exercise, enjoy normal sleep, perform household functions, attend social activities, drive a car or have sexual relations. Two-thirds of Americans suffering from chronic pain say pain causes them irritable behavior or stress, and more than half say it causes a loss of desire or motivation.

One of the best known sufferers of chronic pain is entertainer Jerry Lewis, who suffered years of back pain due to a failed slapstick stunt on a television special in the 1960s that almost left him paralyzed

“I had pain every day for 37 years,” Lewis says. “The pain was under everything – the telethons, the concerts, the appearances. When I was on stage, the adrenaline was overpowering. But after I took that last bow, I had to be helped to the dressing room. The pain was that severe.”

After years in which no therapy – including spas, massage, injections of pain medicine and morphine - worked for his pain, Lewis was in such distress that he contemplated suicide. At the time, in early 2002, he couldn’t walk more than a few steps, and his sleep was disrupted. “Despair rides along with chronic pain like a partner,” Lewis says. “I was ready to walk into an 18-wheeler or a fan jet or blow my brains out. I didn’t think I’d make it another day.”

Lewis was middle-aged when he began experiencing chronic pain. But younger people can also be victimized.

At age 26, Laura ruptured two discs in a household accident. She was standing on a clothes dryer reaching into a cupboard when the dryer began to tip. Laura hung on to the cupboard, wrenching her spine.

“Within a week, I couldn’t walk,” Laura remembers. “I thought it was just a strain – I was much too young to have anything more serious. After toughing it out for days, I finally consented to a trip to the emergency room. The narcotics they gave me should have been enough to drop a horse, but I just cried at the futility of such an ineffective treatment.”

After spending a year in physical therapy, Laura still wasn’t able to turn over in bed without using the headboard to help her roll over. A disectomy and a year of recovery later, and she felt about 50 percent better. But the pain persisted.

Laura tried steroid injections, but they only gave her temporary relief. Surgery wasn’t an option, because it would add to scar tissue from her first surgery that was leading to additional pain.

Neurostimulation for chronic pain

For both Jerry Lewis and Laura, the solution to long-standing pain came in the form of neurostimulation.

Neurostimulation, first developed in the 1970s by Medtronic in partnership with physicians, uses an implantable medical system to deliver tiny electrical pulses to the spine to block pain signals from reaching the brain. The device is about the size of a stopwatch and is typically implanted under the skin of the abdomen and connected to thin flexible wires called leads that deliver the electrical pulses. Based on individual patient need, neurostimulation therapy can be customized and adjusted to achieve optimal pain relief. In contrast to other surgical procedures, neurostimulation is completely reversible and causes no permanent anatomical changes.

“The light at the end of the tunnel was a spinal cord stimulator,” Laura says. “I haven’t regretted my decision for a minute. Instead of dulling my pain and personality with heavy-duty narcotics, neurostimulation masks the pain. I’m able to do the things I once enjoyed without fear of a “flare-up” that can last for days. I no longer limp or use a wheelchair in the mall because I can walk the whole way. I can be a mother to my two little boys again, and a wife to my husband.”

For Jerry Lewis, the implantation of a Medtronic neurostimulator also proved a life-changing, or perhaps even a life-saving, event.

In April 2002, Lewis underwent a trial with neurostimulation to determine if the therapy was right for him. The trial was a success. He had 100 percent pain relief. His doctor said Lewis called him every day during the trial to say he wanted a permanent system.

A few days later, he got exactly that.

“On the day of the implant, I told my housekeeper four times that I had no pain,” Lewis says. “I was reborn. That’s the best way to put it. I get up every morning and say, ‘Thank God;’ I open my eyes without pain.”

The above patient stories capture individual successful experiences with Medtronic neurostimulation systems. Results vary; not every individual will receive the same results.

Medtronic therapies for chronic pain

Patients who receive a neurostimulator must meet certain criteria, including:

• More conservative therapies have failed to adequately help the pain
  
• An observable pathology exists that is associated with the pain
  
• Further traditional surgical intervention is not indicated
• Psychological evaluation and clearance for implantation have been received
• No medical issues exist that would present problems with doing the surgery
• The screening test is successful

Implantation of a neurostimulator typically takes less than two hours. After the procedure, the physician programs the neurostimulator settings for optimal pain relief. A hand-held patient programmer allows patients to adjust the stimulation level within the setting the physician has established. Depending on the need for pain control, patients can adjust pain management settings and turn the system on and off.

Medtronic’s latest neurostimulators include the RestoreADVANCED® and PrimeADVANCED® neurostimulators. The RestoreADVANCED neurostimulator is a rechargeable device with an FDA-approved battery life of nine years that is usually recharged every four to six weeks. The PrimeADVANCED neurostimulator is a non-rechargeable version, typically replaced at least every five years. Both neurostimulators can accommodate 16 electrodes.

Although neurostimulation therapy cannot guarantee complete relief, and complications include lead migration, loss of paresthesia, or stimulation, and infection, published clinical reports have shown that for many patients, it can significantly reduce chronic pain and disability and can dramatically improve quality of life.

The PROCESS study

One recent clinical study, the largest of neurostimulation ever conducted, showed that Medtronic neurostimulation therapy plus conventional medical management provided patients suffering from chronic neuropathic back and leg pain significantly greater pain relief, quality of life, functional capacity and treatment satisfaction than conventional medical management alone after six months.

In the study, called PROCESS (for PROspective randomized Controlled trial of the Effectiveness of Spinal cord Stimulation), 48 percent of patients receiving neurostimulation therapy plus conventional medical management experienced a 50 percent or greater improvement in leg pain compared to 9 percent of patients assigned to receive only conventional treatments.

”Patients with persistently disabling neuropathic pain in the back and legs represent one of the most difficult treatment problems in clinical practice,” says Krishna Kumar, M.D., Clinical Professor, chairman of the neurosurgery department at the University of Saskatchewan’s Regina General Hospital and the study’s principal investigator. “As a result of the PROCESS findings, neurostimulation therapy should be added to the list of conventional treatments and routinely considered for appropriate patients.”

The PROCESS study design randomly assigned 100 patients from 12 academic medical centers in Australia, Belgium, Canada, Israel, Spain, Switzerland and the United Kingdom to receive conventional medical management or Medtronic neurostimulation therapy for a period of six months and patients were followed for a total of 24 months.

The study reports complications and adverse events after 12 months of treatment. The main complications among patients who received neurostimulation therapy included electrode migration, infection and loss of paresthesia. Twenty-four percent of patients in this group experienced an event that required surgery to resolve. In addition, some patients in each group experienced non-device related events, including an adverse event reaction to a drug or the development of a new illness, injury or condition.

Other Treatment Options for Chronic Pain

Another type of medical technology from Medtronic to treat chronic pain is known as intrathecal drug therapy, a fully implantable and programmable method of continuous drug delivery. Such systems have been in use clinically since the 1980’s, and offered commercially since 1991. Advantages of intrathecal therapy include dosages that can be varied throughout the day, and the potential for a lower dose compared with oral drugs, which may result in reduced side effects.

Intrathecal drug delivery systems consist of a pump and catheter, both of which are surgically placed under the skin. The pump releases the medication at the set rate, and the medication flows from the pump, through the catheter to the site of delivery in the intrathecal space within the spinal canal. Pain specialists can program the pump to deliver different amounts of medication at different times of the day, depending on the patient’s individual needs.

Like neurostimulation, intrathecal drug delivery is designed to interfere with pain signals before they reach the brain. Pain specialists can help a patient decide whether he or she is a candidate for one type of pain therapy or another. For more information on medical technology to relieve chronic pain, visit www.tamethepain.org.

“Medtronic offers a range of effective chronic pain management options, from minimally invasive spine surgery to neurostimulation and intrathecal drug therapy,” says Richard E. Kuntz, M.D., senior vice president of Medtronic, Inc., and president of the company’s Neuromodulation business, which includes Global Pain Management. “We are committed to making ongoing investments across the company in clinical research and product development for the benefit of people with chronic pain and their physicians.”