Lakshmi Neuro Clinic
Chronic pain is probably the biggest problem faced by mankind. Chronic pain means pain persisting for more than 6 months or recurring even after treatment. Common chronic pain conditions include chronic headache, neck and shoulder pain, low backache, pain of the hands and legs, arthritis pain, neurogenic pain (pain resulting from damage to the peripheral nerves or to the central nervous system itself), psychogenic pain (pain not due to past disease or injury or any visible sign of damage inside or outside the nervous system). Cancer pain, pain due to failed back surgery syndrome (pain not relived by back surgery) and pain due to diabetes mellitus form another category. Chronic pain may cause other symptoms or conditions, including depression and anxiety. It may also contribute to decreased physical activity given the apprehension of exacerbating pain. Conversely it may itself have psychosomatic or psychogenic component to its cause.Studies have shown that chronic pain impairs the ability to direct attention and people with high-intensity chronic pain have significantly reduced ability to perform attention-demanding tasks. In experimental testing, two-thirds of individuals with chronic pain demonstrate clinically significant impairment of attention, independent of age, education, medication and sleep disruption, suggesting that pain diminishes working memory.
Chronic pain may be caused by many conditions and situations. Anything from a bad mattress to bad posture to highly malignant tumours can cause chronic pain. Chronic pain then develops a psychological dimension which perpetuates the process.
As we all know chronic pain affects our day to day life. Unfortunately these patients go from doctor to doctor getting pain killers or worse they self medicate. Most painkillers when used repeatedly can affect the kidneys (analgesic nephropathy) and the heart (heart failure). Chronic pain disables more people than cancer or heart disease. It costs the U.S. economy more than $90 billion per year in medical costs, disability payments, and productivity. Yet it has received little attention from medical researchers until recently and is one of the most under funded major health problems. In our country also people were not bothered about chronic pain till recently but the awareness is getting on. For every person seeking relief from chronic pain, others are inevitably affected: husbands and wives, parents and children, friends, employers and co-workers. Chronic pain can interfere with every aspect of a person’s life: work, relationships, self-esteem, and emotional well-being. Chronic pain brings a burden of depression, anxiety, frustration, fatigue, isolation, and lowered self-esteem. Pain makes it hard to work, hard to play, hard to get support from others, and hard to live a happy life. Chronic pain shatters productive lives. Studies have also found association between chronic pain and infertility in women.
Treatment of chronic pain usually involves medicines and supportive therapy. Medicines used for chronic pain include anti-inflammatory drugs, antidepressants and anticonvulsants. Different types of medicines help people with different types of pain. Several types of therapy can help ease your pain. Physical therapy (such as stretching and strengthening activities) and low-impact exercise (such as walking, swimming or biking) can help reduce the pain. However, exercising too much or not at all can hurt chronic pain patients. Occupational therapy and behavioural therapy teaches you how to pace yourself and how to do ordinary tasks differently so you won’t hurt yourself. Lifestyle changes are also an important part of treatment for chronic pain. Getting regular sleep at night and not taking daytime naps should help. Attention to simple activities like proper posture, the bed we sleep on etc can make a lot of difference to some patients with chronic pain.
In those patients who are not relieved by conservative measures, surgical measures can be advised. This is especially important in patients with cancer pain, failed back surgery syndromes and other complex regional pains. The main methods are intrathecal drug delivery systems, dorsal spinal cord stimulators and deep brain stimulators.
Spinal cord stimulation is the most common neurostimulatory implant used. Here stimulating electrodes are positioned in the epidural space of the spinal cord and the dorsal column is stimulated which causes good relief of pain (pictures below). The pulse generator (battery) is placed in a pouch under the skin.
Spinal cord stimulator is indicated in failed back surgery syndrome (recurrence or persistence of pain after apparently successful surgery), refractory angina (patients with angina but not candidates for angioplasty or bypass surgeryor not benefitting from these two), diabetic neuropathy (severe pain especially in the legs at night not controlled by drugs), brachial plexus (nerves going to the hand) injury pain, complex regional pain syndrome, peripheral vascular disease etc. More than 80% of patients have very good pain relief. The surgical procedure is very simple and the complications are very less (1 -2%), related to hardware and are reversible.
Some conditions like pain due to cancer especially in the terminal stages, osteoporotic pain, post stroke pain etc benefit from intrathecal preservative free morphine which is delivered continuously into the subarachnoid space with a pump placed (picture above) under the skin in the anterior abdomen. A person requiring 200 mg of morphine orally will need only 1 mg of morphine intrathecally. Compared to intravenous medications, the therapeutic effect of intrathecal drug application lasts longer and the rate of systemic side effects is reduced. Also there is no problem with addiction, tolerance and drowsiness. More than 70% of patients report very good pain relief and upto 20% report fair pain relief. The usual complications again are related to equipment failure but these are minor and reversible.
The same pump filled with baclofen can be used in patients with severe spasticity due to various causes like spinal cord injury, cerebral palsy, multiple sclerosis etc. Recently the baclofen pump has been successfully used in patients lying in persistant vegetative state (coma state) for a few years.
For some resistant pain syndromes like the central post stroke pain, deep brain stimualtion is also being used. But this is a very costly procedure and involves brain surgery and so not very common.
Written by -
Consultant Neurosurgeon, Maldicare