[Ming Pao Special Report] Sciatica, it turns out, can be divided into real and fake. What is the difference between the two? Is the source of the pain the spinal joints or the buttock muscles? Why does the pain persist even after taking painkillers?
Cheng: Dr. Cheng Chi-man
Lee: Dr. Lee Yuk-ming
Cheng: With sciatica, because the spinal nerves are compressed, in addition to back pain, patients also complain of leg pain and weakness. In severe cases, they are referred to an orthopedic surgeon for surgery. How does the specialty of pain medicine help these patients?
Lee: Sciatica refers to a condition whose source lies in the lumbar spine. However, some patients present with symptoms similar to sciatica, yet the problem does not originate in the lumbar spine. Therefore, the first step is to distinguish between real and fake sciatica. In real sciatica, the source of the pain is in the lumbar spine; the most common cause is a herniated disc pressing on the nerve and causing pain. The pain, numbness, and other sensations spread from the lower back down the entire leg. In fake sciatica, the source of the pain lies outside the lumbar spine; a common cause is spasm or tightness of the piriformis muscle in the buttock, which irritates the sciatic nerve, with the pain, numbness, and other sensations occurring above the knee.
Treatment for sciatica is mainly divided into three categories:
- Conservative treatment: including medication, physiotherapy, and acupuncture
- Interventional treatment: injections, radiofrequency therapy, spinal cord stimulation
- Surgical treatment: removing or repairing damaged or proliferated tissue
Pain medicine specialists are skilled in medication and interventional treatment.
Over-the-Counter Drugs Can Hardly Stop Nerve Pain
Cheng: Non-steroidal anti-inflammatory drugs (NSAIDs) are often misused. Many pain patients buy them on their own from the pharmacy, even choosing high doses. What are the risks? Some patients also believe that painkiller injections are more effective than oral painkillers. Is that true?
Lee: Whether NSAIDs can effectively relieve pain depends first on distinguishing which type of pain it is. Pain is generally divided into three types:
- Somatic (skin and flesh) pain: external injuries such as abrasions and cuts
- Visceral pain: stomach pain, abdominal pain, menstrual pain in women
- Neuropathic pain: sciatica, trigeminal neuralgia
NSAIDs are very effective against somatic pain. But sciatica is primarily neuropathic pain, mixed with some somatic pain. Treating neuropathic pain requires medications specifically targeted at nerve pain. Taking ordinary anti-inflammatory painkillers on your own is like casting medicine at random and does not help relieve the pain. In addition, NSAIDs have a ceiling effect — that is, a maximum effect. Once a certain dose is reached, taking even more does not increase the effect, but the side effects keep growing. So overdosing is absolutely not recommended.
Also, is an injection more effective? From a pharmacological standpoint, for the same drug, whether injected or taken orally, the therapeutic effect should be the same; it is just that injection is absorbed faster by the body, while oral absorption is slower.
Eighty Percent of Patients Recover Spontaneously Within Six Weeks
Cheng: For sciatica, when should one receive physiotherapy? When is surgery needed? Which is more effective for pain relief?
Lee: The main cause of sciatica is a herniated disc, but our body has a “cleanup” function that can gradually clear away the herniated disc. Eighty percent of patients recover spontaneously within six weeks.
Painkillers and physiotherapy are meant to help patients reduce pain during this period. Physiotherapy can be divided into two types. One is active physiotherapy, where patients actively train their muscles and improve their sitting posture; the pain-relieving effect is not immediate, but the benefit is more long-term. The other is passive physiotherapy, where the physiotherapist performs treatments such as ultrasound and hot compresses; this relieves pain quickly, but the effect is more short-lived.
However, when the pain persists, or nerve compression causes leg weakness, loss of sensation, or even incontinence of urine and stool, then surgery is needed to remove the herniated disc.
An Abnormal Disc Does Not Necessarily Require Treatment
Cheng: In treating sciatica, is the goal only to relieve pain?
Lee: Research shows that of 100 people who undergo an MRI, 80 have abnormal or degenerated discs, but they may not have any clinical symptoms and need no treatment. On the other hand, patients who come for treatment because of a herniated disc almost all seek care because of pain, so pain relief is very important. However, if in addition to pain the patient also has severe symptoms such as leg numbness, weakness, loss of sensation, or incontinence of urine and stool, this indicates nerve compression and requires surgical treatment.
Article date: April 18, 2016 Ming Pao
Information provided by Dr. Lee Yuk-ming, Specialist in Pain Medicine
