[메디게이트뉴스 박민식 기자] It is easy to see people who complain of pain for a long period of time in the vicinity. However, since there is a low awareness that pain can be a disease, it is common to endure until it can be endured or not to go to the hospital because it is not a big deal.
In fact, according to the International Association for the Study of Pain (IASP), 20% of the world’s population is affected by chronic pain, and the World Health Organization estimates that one in ten adults is newly diagnosed with chronic pain every year. Among them, it is known that 1 in 10 people worldwide suffer from neuropathic pain, but only about 10% of patients receive treatment.
Neuropathic pain is chronic pathological pain that persists for more than 3 months due to nerve damage or abnormal nerve function. If left untreated, it can lead to insomnia and depression, which can worsen the quality of life, so early diagnosis and treatment are important.
Medigate News interviewed Professor Kim In-joo of the Department of Endocrinology and Metabolism at Pusan National University Hospital to hear about neuropathic pain and treatment.
Various diseases that cause nerve damage are the cause… Diabetes is the representative
Q. What is neuropathic pain and how is it different from other pain?
When we get sick from being hurt or cut by a knife, it’s because we’ve received a stimulus that can cause pain. On the other hand, a case in which pain is abnormally felt despite not enough stimulation to cause pain due to various diseases that can invade nerves or pain occurs even when there is no stimulation is called neuropathic pain. A typical example is diabetes, lack of various nutrients, or nerve damage caused by alcohol. It also includes abnormal pain or abnormal sensations in the area of nerve damage after cerebral infarction.
Q. What are the specific causes of neuropathic pain?
For example, when blood sugar is high in diabetes, when abnormal metabolic activity occurs in nerve cells, various substances that cause nerve damage are generated. As a result, when nerves are damaged, abnormal stimuli are transmitted to the brain, leading to the thought that ‘I can now feel pain’. Neuropathic abnormalities that can occur in various diseases can be inferred in this way. The root cause can be blood circulation problems, nerve cell damage, nutritional aspects, and inflammatory reactions, which are considered the basic causes of various diseases. In the end, it can be said that metabolic disorders and high blood sugar act in combination with those starting from hyperlipidemia. Therefore, in the case of diabetes, it can be understood that inflammatory substances caused by metabolic disorders including blood sugar, blood circulation disorders, and oxidative stress caused by blood sugar itself are several mechanisms that cause neuropathic pain.
Q. What is the current prevalence of neuropathic pain in Korea?
The prevalence varies greatly depending on the diagnosis method. Based on the results of a survey conducted by the Korean Diabetes Association, it is believed that diabetic neuropathy is present at a rate of 40 to 60%. In fact, up to 90% of cases have been reported if only the symptoms of numbness or dullness felt by patients are identified. Depending on the degree of attention, the frequency of neuropathy can be seen as a disease with a very wide range of prevalence.
Early detection is important… Diagnosis can be made through questionnaires, monofilament tests, etc.
Q. How is neuropathic pain diagnosed?
Diagnosis may vary depending on which disease causes neuropathic pain, but neuropathic pain usually refers to a problem in the peripheral nerve rather than the central nerve. Representative peripheral nerve functions are to sense pain, to sense vibration, and to sense temperature. It plays a very important role in the functioning of peripheral nerves. In addition, the maintenance of renal function, the sense of urination in the gastrointestinal tract, and various autonomic functions regulating urination activity are eventually included in the category of peripheral nerves. In this way, the test is performed to evaluate the sensory nerve by checking for abnormalities in peripheral nerve function. Methods to evaluate temperature and vibration sensations implemented in several hospitals, and methods to detect abnormalities in slightly larger nerve fibers through nerve conduction tests performed in neurology or rehabilitation medicine are indirect, but can confirm neuropathic pain. possible diagnostic method.
More precisely, there are test methods that look at the number and shape of the nerves distributed by the subcutaneous nerve through a biopsy. Alternatively, the degree of nerve distribution in the cornea can be evaluated by a microscopic method. Although it is a more definitive diagnostic method, biopsy or corneal examinations are not easy to do because certain equipment and personnel are required.
An easy way to access the primary care site is to score it through a questionnaire that evaluates the symptoms of neuropathic pain. In addition, monofilament testing can be performed. The monofilament test is a method to check whether the sensory function works normally by touching the patient’s hand or foot as a small and thin filament bends when a load of 10 g is applied. Through this, identifying which sensory is lost can be an important basis for diagnosing neuropathic pain.
Q. Early detection of neuropathic pain is important. What is the important part for this?
First, I think of it as mutual interest and communication between the patient and the doctor. Korea is a country with a very advantageous system because the hospital threshold is relatively low. Nevertheless, the elderly have a tendency to tolerate discomfort well. In some cases, the diagnosis is delayed because it is not possible to express the point of ‘I am sick or uncomfortable’ within a short treatment time.
Because doctors have to see the patient within a limited time, it is difficult to ask the patient for symptoms such as whether he has pain, paresthesia, or has ever experienced a cold or tingling sensation. Because pain is a problem that can be caused by so many different causes, people often experience a skeptical situation where they ask the patient if their hands or feet are numb or sore, and then find symptoms that are difficult to solve and regret asking the question. These are major obstacles to early detection of neuropathic pain.
Q. There are various causes and diagnostic methods for neuropathic pain, but is the treatment the same?
Yes. Diabetes, for example, is more prone to nerve damage when blood sugar is high. Nowadays, there is a lot of interest in the range of fluctuations in blood sugar. This is because, the more severe the fluctuations in blood glucose after fasting and meals, the more severe the neuropathy or pain caused by neuropathy tends to respond well to general treatment.
The unique characteristics of the disease and the surrounding circumstances must be judged in a complex way. Patients who complain of numbness or peripheral nerve abnormalities due to nutritional deficiency or lack of minerals and vitamins after chemotherapy may find it difficult to recover their symptoms if adequate nutrition, minerals and vitamins are not supplied. Diabetes mellitus should first pay attention to blood sugar control, drinking and smoking, and then look at nutritional imbalances and vitamin and mineral imbalances. Lastly, you need to pay attention to the blood circulation part.
In addition, if the pain or symptoms are not severe and left unattended, there will be great individual differences depending on the patient, but it will cause a lot of trouble in daily life. This is because in many cases, the rhythm of life is disrupted by not being able to sleep well because of the pain, leading to anxiety and depression. Naturally, students and office workers have a significant impact on their lives, such as poor academic performance and work performance.
Therefore, treatment, treatment, and interest in the pain itself are very important. In terms of treatment, it is necessary to find the causes of pain and correct them as much as possible, and then to control various symptoms including pain well. None of these can be neglected, so a balanced approach must be taken.
Because of neurotransmission problems, only pain relievers are limited… Emphasis on the importance of anticonvulsants such as pregabalin and gabapentin
Q. What are the selection criteria or the most important aspect when treating neuropathic pain medications?
When using drugs such as pain relievers, there is a method of starting with a low dose and intensity and gradually increasing it. Conversely, there is a way to start intensive treatment from the beginning and reduce the amount of medication. When the pain is too severe, non-steroidal analgesic and anti-inflammatory drugs can be considered, but neuropathic pain is a case where the pain is felt with only a small sensation due to an abnormally increased sensation.
Rather than relying solely on general pain relievers, a treatment that blocks or stabilizes a problem in nerve conduction, that is, nerve transmission, is more important. The importance of anticonvulsants that regulate and stabilize abnormally active parts of the neurotransmitter system, such as pregabalin and gabapentin, and relieve pain and abnormal sensations, is emerging. It has been a trend for the past few years to recommend the use of such drugs as the first line. In recent years, the scope of application of anticonvulsants such as pregabalin and gabapentin is gradually expanding. Previously, it was used for diabetic neuropathic pain, trigeminal neuralgia, postherpetic neuralgia, and more recently for disc-induced neuropathic back pain. The indications for the treatment are gradually expanding.
Q. It is known that diabetic neuropathy pain accounts for the largest share among patients with neuropathic pain. What proportion of diabetic patients suffer from diabetic neuropathy pain?
The overall prevalence of diabetic neuropathy is about 5%. Although there are some differences depending on the survey results, according to the survey results of the Korean Diabetes Association 10 years ago, it was reported that 30-40% of all diabetic patients with neuropathy were accompanied by pain.
Q. About 50% of patients with diabetic neuropathy have no symptoms. How is this diagnosed?
Patients with asymptomatic diabetic neuropathy pain experience discomfort for a considerable period of time and experience negative (negative) neuropathy without pain and abnormal sensations. In this case, nerve damage may be more severe. When listening to the histories of patients who have become very numb and have no sensation of touching their feet, it is often the case that the time of previous positive neuropathy symptoms has elapsed. For these patients, it is much more difficult to restore normal sensation.
Q. In general, diabetic patients take various drugs. What should be kept in mind when treating patients with neuropathic pain who are taking multiple drugs?
Pain is a very subjective part, so it is easy to start taking medication for treatment, but when you stop taking it, you need to think deeply about it from your doctor. Similarly, it is difficult to give a clear answer on the dosage of drugs to treat neuropathic pain.
Let’s assume that an elderly patient who is taking multiple medications has good pain control by using one or two medications, and then the pain symptoms are greatly improved. In this situation, I worry a lot about how to reduce the duration and dose, and whether it is possible to discontinue the drug. After that, blood sugar control is managed to prevent symptoms from reappearing or progressing due to nutritional and mineral imbalances. It is important to focus on more essential management and to think about what kind of treatment strategy should be established to control the symptoms when symptoms recur.
Communication with both doctors and patients is the key to solving problems
Q. What are the latest treatment guidelines or trends for neuropathic pain?
As for diabetes, the basic principles are the same, such as the patient thoroughly managing blood sugar control. Next, drugs that control neurotransmission abnormalities such as pregabalin and gabapentin are very important first-line treatments. The use of the drug is gradually expanding, and the future prospects such as whether treatment using growth factors will actually help patients is a situation that needs to be watched more closely. In particular, since pain and paresthesia are due to various causes, it is important to approach them with interest. Symptoms such as nighttime muscle cramps and restless legs disorder, which patients often experience, are recognized through consultation with the attending physician and are sometimes improved by treatment in neurosurgery.
Q. Lastly, what would you like to say to patients with neuropathic pain or medical staff?
It is very important to maintain a quality aspect of the patient’s life during treatment. Because pain itself is a big factor that can reduce life, it should be approached with care by medical staff. Among patients, there are many cases where the attending physician feels satisfied enough just to listen to the patient and communicate with the patient, even if all discomfort cannot be resolved medically. As a doctor, I feel great satisfaction and joy when I find clues to solve problems in the process of communicating with patients and help them. I would like to ask my fellow doctors to be interested in their patients and to approach them actively.
Patients can effectively consult within a limited time limit if they come up with or take notes of symptoms and questions to tell their doctor before treatment. In fact, among diabetic patients, the calves were heavy and numb, so they thought it was diabetic neuropathy and received counseling, but varicose veins in the lower extremities were discovered. As such, when patients and doctors communicate with each other, greater synergy can be created.