Neuropathic pain is a very common chronic condition that poses a challenge for doctors. It’s the result of a primary lesion or dysfunction in the nervous system. Roughly two to five per cent of Canadians are affected.
Pain is a natural product of injury. We twist our ankle and it hurts for a few days. Or we break a bone and feel the effects while it heals. Generally, as healing progresses, the pain becomes less severe until it eventually fades entirely.
Unfortunately, many people will experience ongoing pain where there is no obvious injury. Or they will continue to have pain at the site of an injury long after it has healed. In these cases of neuropathic pain, the nervous system is not performing its proper function of just alerting the individual to an injury. Instead, it’s malfunctioning and sounding an alarm where none is needed.
The nervous system itself becomes the cause of the pain.
Some of the most common reasons for neuropathic pain are associated with diabetes. Called peripheral diabetic neuropathy, this pain arises after an episode of shingles (post-herpetic neuralgia), phantom limb pain after amputation, and pain that persists after severe trauma or surgery such as mastectomy.
Other types of neuropathic pain can result from infections, metabolic abnormalities, chemotherapy, radiation, neurotoxins, inherited neurodegeneration, nerve compression, inflammation or tumour infiltration.
While short-term pain related to an injury serves a protective purpose, neuropathic pain serves no biological function and can go on for decades.
If it’s not dealt with effectively, chronic pain can lead to additional symptoms such as chronic anxiety, depression, fear, sleeplessness and difficulty functioning in many areas of life.
Obviously, treating this kind of pain is important so individuals can continue to enjoy activities, work and take part in social situations. In fact, early recognition and aggressive treatment of neuropathic pain is crucial in ensuring it doesn’t remain a chronic and severe problem.
This is where the challenge begins.
Unfortunately, neuropathic pain doesn’t respond well to common pain-relieving medications such as analgesics and non-steroidal anti-inflammatory agents. Taking an aspirin every few hours won’t do much to alleviate suffering.
Some medications such as antiepileptic drugs have shown positive results in treating neuropathic pain. In fact, gabapentin and more recently pregabalin have been approved for use on some forms of neuropathic pain.
Some studies have also shown the older antidepressant medications, called tricyclic antidepressants, have effectively treated neuropathic pain. Unfortunately, these drugs can have fairly unpleasant side-effects for an often minor benefit.
Physical rehabilitation, behaviour therapy and relaxation training can also help.
But the magic bullet has not yet been found.
If you are one of the many Canadians who suffer from chronic neuropathic pain, don’t give up hope. Speak with your doctor about available options.
Paul Latimer is president of Okanagan Clinical Trials and a Kelowna psychiatrist.