Lecture 05 : Week 07

[Music] namaskar this is Dr anurag agrawal a pain physician and Professor anesthesiology at Dr Ram manur Lya Institute of Medical Sciences lnno utar Pradesh bat India today we are going to talk about neuropathic pain and management I have done my mbbs and MD anesthesiology and pdcc in pain manage medicine from Banaras Hindu University uh I have a special interest in the Interventional management of chronic pain and Spine and spine endoscopy I am a vice president of napim up chapter I am the founder president of endoscopic spine and Interventional pain Society of India I member of pain medicine Board of national na Board of examinations for medical Sciences India and I am a member of cancer Aid Society Ethics Committee I am working currently as pain physician and professor at Dr Ramya Institute of Medical Sciences LNO so why we need to talk about the neuropathic pain because there is a rise in the NCD across the world that is non-communicable diseases there's rise in the cancer pain there is rise in different chronic conditions like the HIV and AIDS there is rise in the age of living of the population it is reaching up to 80 years and beyond that in most part of the developed and developing world and there is changes in the lifestyle unhealthy lifestyles are increasing we are eating more in the outside we are going away from the Healthy Lifestyles which our elders used to have uh then there are poor socionomic status there environmental factors and degenerative conditions which are are increasing and moreover stress stress and stress in each and every uh population group so all these things are causing neuropathic pain so most of the patient come to our pain medicine oped that I have got so many AES and pain that a new one would have to wait a week before I could feel it so that is the condition unfortunately and this is a big challenge chronic pain itself is going to be the biggest burden on the coming world and the government of the day across the globe are thinking and are forced to think about the treatment of chronic pain uh we as a pain physician as you know that pain medicine is upcoming super specialty of anesthesiology uh where we are having different courses but we are still unable to meet the demand and supply chain demand is much more pain Physicians are required to serve the society but we are producing less so we urge the government to take care into this direction also so what is the coming back to the topic there can be two type of pain which is nosis aptive pain and then there is a neuropathic pain so nosis aptive pain signals that pain signaling pathway are intact whenever you get your head bump on something you get a pain and that means means that body is able to perceive the injury and to Signal it as a pain that means the network is good and clean but neuropathic pain means that there is some problem in the network and what is that Network they are nerves they can be peripheral nerves they can be central nervous system so neuropathic pain is which is the pain initiated or caused by a primary Leon or disfunction of the nervous system then neur neuropathic pain also is a direct consequence of the Leon or a disease like the cancer or like the chemotherapy or like any other long disease like the herpes diabetes they all can cause dysfunction of the connecting system that is the nerves so what is the difference between the nociceptive pain and neuropathic pain nociceptive pain means that there is a stimulation of peripheral nerve fibers by noxus stimuli suppose you have some injury you have some disease and uh then your body senses that something is wrong you put your finger in near the flame so the nerve sensation nerve ending near the finger they sense that something is wrong it gives the signal to the brain and brain ask the body to withdraw your finger from the fire so that is the no receptive pain which means that body is sensing that there is some noxious stimuli which can be thermal chemical Sharp or dull continuous and the examples are the absis like the trauma like the post-operative pain and these type of pain they usually respond to the overthe counter available drugs like the Nets ibuprofen dienic sodium and others and they also respond to the opioid and other other the treatment and most of the acute pain which happens due to some trauma due to some injury they are type of uh noptic pain but what about the neuropathic pain they are due to the damage or disease of any part of nervous system and the symptoms are usually burning tingling electrical shock like pain like it happens in the trial neuralgia stabbing and pins and needle patient will tell you I'm feeling tingling all over my body or half of my body or in my arm or in my leg so that is type of neuropathic pain and the causes can be Phantom limp pain herpes Zer after herpes many patients suffer from the severe kind of neuropathic pain diabetes it causes peripheral uh axonopathy and uh severe pins and needing sensation in the lower limbs especially say this neuropathic pain unfortunately do not respond to the commonly available analgesic drugs like the anets and opioids but they do respond to the uven drugs which I told you earlier in my another lecture uh the these are the drugs which were meant and discovered for some other purposes but they were found later on to work on certain aspects of pain especially the neuropathic pain and the most common examples are the tricyclic anti-depressant and the anti-convulsant drugs like the gabapentin and the pabin and most of the chronic pain they do have a component of neuropathic pain also so what is the incidence of neuropathic pain those there are multiple studies across the world in Europe they have found that the incidence and prevalence in their society is 8% and 7% and 10% of those patient they told the investigators that we are getting affected by this neuropathic pain in our day-to-day life that means our life is being disturbed by this kind of pain so herpes Zer causes up to 8% patients of herp zoster they suffer from the severe kind of chronic pain then comes the spinal cord injury which is again the incidence is increasing because of the increased road traffic accident across the globe where up to 70% 67% patient they suffer from the uh neuropathic pain then stroke can cause it diabetes can cause multiple sclerosis and the one of the most common condition of chronic pain across the world that is low back pain it also causes the neuropathic pain which goes down the leg with that severe tingling numbing uh numbness burning pin andal sensation and this pain does not help like acute pain actually helps you to take care of your body to remove the body from the acute event or in noxious event but here neuropathic pain is not serving any uh benefit to the body so causes of common causes of neuropathic pain are one and most trinal neuralgia also known as suicide disease unfortunately where the patients are having sever electric shock like pain on their face then comes the post herpetic neuralgia where I told you that 10 to 20% patients suffer from the post herpetic neuralgia diabetes neuropathy Phantom LM pain multiple sclerosis pain after the chemotherapy that is being used for the cancer patients then HIV infection uh alcohol cancer atypical Facial Pain and multiple other causes are there which can cause neuropathic pain so to how can we classify it so it can be classified as the part of nervous system which is being affected like the neuro peripheral neuropathic pain which involves the peripheral nerves and the examples are diabetic neuropathic pain post herpetic neuralgia trial neuralgia postsurgical pain or the CRPS and then it can be Central neuropathic pain where the central nervous system is being involved which can be there after the stroke cerebral vascular EX D that is known commonly known as stroke or spinal cord injury and then comes the sympathetically mediated neuropathic pain where the sympathetic nerves are involved is usually happens with the common type of cancer carcinoma uterus carcinoma uh gallbladder pancreas where the nearby nerves get affected or the Panos tumor in the carcinoma lung cases where it involves the braal plexus and cause severe kind of sympathetically mediated pain which is also known as CRPS that is complex regional pain syndrome so many times it is not possible to determine the iology of neuropathic pain from the uh patient perspective so you need to treat the wholesome patient uh thinking of the neuropathic pain so the pathophysiologies are multiple mechanism are proposed where there can be local nerve injuries there can be sympathetic related pain and there can be release of cyto uh at the different body part which causes the activation of sodium channels in the inured Exon and then there are phenomena known as Central sensitization and plasticity and then calcium channels also get involved so there can be multiple things which can happen where there can be Alodia then that means when patient perceives a normal touch as a painful touch like here you touch and patient says that I am having pain then there can be hyperalgesia when the patient perceives too much of pain for Less noxus stimuli suppose I pinch the hair so I'm feeling it mildly but patient of with Hyper Alesia may feel is a severe kind of pain so that is known as hyperalgesia so it is considered to be a disease neuropathic pain itself is a disease now because it can happen due to exposure of drugs alcohol and toxins it can be because of trauma it can be because of viral infection it can be neur generative like multiple sclerosis it can be because of the vitamin B12 deficiencies nutritional deficiency cancer can causes metabolic disorder like diabetes can causes and surgical process like amputation Phantom limp pain where the patient has lost his arm but patient is still feeling that I am having this arm intact and that is severely painful when in reality there is no arm so that is known as Phantom limpin very difficult condition to treat but when you get a good pain physician to treat it you get good results so common features which are suggestive of neuropathic pain are paresthesias that means then abnormal sensation is spontaneous or evoked so when you touch the patient here and you touch the patient here and suppose this arm is having neuropathic pain so patient says I am feeling bad when you touch here I am feeling normal here I feeling bad then dises thesia when you feel bad sensation uh byou ing or spontaneously then there is hypesthesia when you feel less that is hypo and when you feel more it becomes hyperesthesia increase sensitivity I'm having the normal sensation but I am feeling too much then there is hypoalgesia when you uh it happens with the diabetes patient when they lose the sensitivity to the pain especially in the lower limbs so in results a small prick a small trauma to their lower limb they do not appreciate it and then it gets bad and they get non-healing ulcers even then there's hyperalgesia and then there is Alodia which we have talked when you feel the non-painful stimulus as a painful one so components of neuropathic pain uh is a pain which can be spontaneous which can be provoked so when this spontaneous it can be continuous or it can be intermittent when intermittent like it happens the trial neuralgia patients are having uh sudden severe electric shock like pain on their face in one or more territory of trial nerve which is the fifth cranial nerve and patient may have it spontaneously they can have it when they eat they chew they brush they uh speak anytime so all these sensation can and then it can be provoked which it can be alodine or hyper so to assess the neuropathic pain uh the goals are to achieve a diagnosis of pain to identify the underlying causes of neuropathy if possible possible to identify the comorbid condition like the diabetes or herpes to evaluate the psychosocial factors that how much this pain is actually affecting the patient's life to evaluate the functional status whether the patient is able or not able to work because of uh pain and then to set goals please remember it is very very important to understand uh many times uh especially in allopathy it is difficult to cure the disease for The Chronic PR problems chronic problems be it diabetes be it heart disease be it kidney disease be it chronic pain so it is very important to set the goals with the patient that look I am not perhaps able to cure your condition but I am certainly able to help you out to manage it so that you can have a good quality of life develop a targeted treatment plan and please remember as I told you pain medicine is a super specialty of anesthesiology which deals EX exclusively with chronic pain problems so we are trained to do that so uh if as a primary care physicians you find that your treatment algorithm is unfortunately not working you should refer your patient to a pain Physicians available near to you so what are the screening tools there are multiple scores have been made uh you can check the Google uh for details the DN four score npq score detect score and lens score multiple so there are multiple questionnaires but the shortcoming with all most of these questions are that they have been developed overseas in the Europe or in America and many times the questions they have are um slightly sensitive or perhaps not suitable for our population so we are working on that as a society uh professional Society uh to develop our own own indigenous pain scores so that we can be they can be effectively used in our patients so then you can do the some clinical examination to check the Alodia where you use a brush to stroke the different part of body and to see whether the patient is having pain or not and pin prick threshold Etc then the again multiple test uh which you should know that specialist do it v f filament test detect question fine brush you can see to see the elodia pin prick to see the hypo or hyperalgesia so what are the treatments of the neuropathic pain so they starts with the again oral or topical treatment because they are easily available easily applicable and they are cost effective so there can be Loken patch or capin patch capin patch is still not available in India but Loken patch is available in India then there are opioids like the trod fental morphine and then the most important drugs for treatment of neuropathic pains are these two classes of drug anti-depressant drugs and anti-convulsant drugs so they are TCA tricyclic anti-depressant and then there are snri to examples are emaline noraline and then there are duitin Vine they are available and they are very effective and then carbamezapine is the drug of choice for the trinal neuralgia sodium vpid lorrine Ox carbine Gaba pentin pavin all these drugs are being used by a pain physician to treat different kind of chronic pain syndromes and they have to be used one by one as per the patient condition then their Advanced therapies like the intal therapy uh where we use a intal pump to supply the medicine to directly to the spinal cord where it works beautifully in certain set of patient uh here opioid drugs like uh morphine as well as some other drug Alpha 2 agonis drugs like the clonidine are being used in India zoton is very costly and not available in India it is only available in US currently so analgesic letter you start with the Costo drug uh then you go to the TCA or antiepileptic and then you use a combination of both the drugs then nmd receptor blocker like the katamine infusion or dextrin oral tablet or spinal analgesia where you use the intrathecal pump so this is the analgesic letter for the neuropathic pain suggested by some authorities like the wo Le is there for treatment of otherwise chronic pain so tiation of medication is very important in the treatment of neuropathic pain because remember none of these drugs are going to affect overnight and they are having their own set of side effects so it is very important that you uh titrate the dose uh of single drug uh till you reach the maximum tolerable drug to the patient before you jump to the Other Drug so it is it takes time it usually takes few weeks to months to realize the potent full potential of a single truck so for the tricyclic antidepressent like emit tripoline you start with a 10 mgram dose at HS at night because it causes a lot of sleepiness to the patient and then you every week 3 to 7 Day you increase it up to the 75 to 50 Mig per day and duration for adequate tiation requires 6 to 8 weeks that becomes 2 months before you jump to the other DS so are the seen with other cases like the Gaba pentin you start with 100 to 300 milligram at night then you increase it every 7th day then it goes up to the 36 migr per day and same is with the opioid and thodol and everything so tiation is the key of successful treatment so uh these are the examples of amaline desipramine as a TCA then anti-depressant duitin Vena faxin anti-convulsant carb carbamazapine phenin ox carbamazapine and then there are multiple other drugs nmd receptor Agonist opioid topical agent and others so the drug treatment uh goes in favor of TCA snri alagon pabar pentin topical lokan then the commonly available anets and opioids uh for the neuropathic pain so to talk about some specific conditions diabetic neuropathic pain that is a non-painful paresthesia so I as I told you in diabetes uh the peripheral axonopathy happens peripheral diabetic neuropathy is the name scientific name where the patient have hyp hypalgesia or hypoth IA in the periphery of the lower limbs especially it affects about 50% of diabetic patient where they feel pricking or taking sensation and the affected fibers are a Beta fibers of the nervous system and this is distal symmetrical and sensory neuropathy and they respond usually to tricyclic anti-depressant with or without trod same cames the central neuropathic pain like it happens with stroke and spinal cord injury uh up to 50 % patient complain of the burning sensation and they develop pain within 3 months of the incident of a stroke or injury and there is Alter sensation they also respond to the carbamezapine Gaba pentin prein and the combination of drug you need to use then CRPS as I told you is a initial uh noxious event is there like trauma or there is immobilization because of anos suppose you have a wrist fracture and you were put in a cast or plaster for 3 weeks or 6 weeks and during that immobilized period you develop a CRPS type 1 or type two injury uh where there is a continuous pain Alodia and Hyper Alesia there are edema skin changes or motor symptom there temperature differences are there so there are multiple drugs physiotherapy steroids are being used in the initial period then later on estet gangon mipsy that is a minimally invasive pain spine intervention is being done by the pain Physicians trained pain Physicians to relieve the patients of their symptom so in cancer patients the prevalence of neuropathic pain is again very high up to 19 to 4% up to 20% in different study and neuropathy caused by cancer treatment is much higher than the disease that is the unfortunate part so all our treatment they also carry some or other sort of side effects so we always need to check the risk and benefit ratio before prescribing any treatment to our patients so standardized approach for assessing neuropathic pain is likely to lead to a more appropriate treatment strategy so here you can see that this is a hand and foot syndrome following a chemotherapy grade one where there is numbness dysesthesia paresthesia tingling painless swelling rhythma or discomfort of hand then grade two painful rhythma and swelling of the hand and feet then grade three uh moist desquamation skin starts peeling off ulceration blistering severe pain of hands and feet and severe discomfort so likely causes of cancer neuropathic pain are predominant acute pain happens in the painful peripheral neuropathy due to chemotherapy and radiation can also causes plexopathy and predominantly chronic neuropathic pain direct tumor infiltration of peripheral nerve like it happens in the uh pancost tumor due to lung cancer tumor infiltration of the nerve plexus radiculopathy painful peripheral neuropathy postsurgical pain syndrome and post- radiation pain syndrome so identify cancer neuropathic pain that by any pain in a cancer patient is persistent of severe the pain which is particularly Intense or distressing in quality if the pain is not responding to the standard approach and like uh there is a spinal cord compression because of the tumor so you can feel that it is a chronic neuropathic pain so how to use the opioid analgesic in the cancer neuropathic pain you need to optimize the opio resimen titrate upward until effect or intolerable side effects are coming maximally manage side effects to allow for the further tiation if possible and if unacceptable side effects without adequate analgesic effect consider adjuvent analgesic or switching to the alternate open it so uh our experience is multiple all kind of neuropathic pain can be seen in the cancer patients it can happen in the abdominal pain uh because of the tumor or cancer of gallbladder which is very prevalent in this part of country caroma pancreas carcoma urinary bladder or cervix in females uh it can be due to the chemotherapy which results in the peripheral neuropathy intal CT and we use wh L to treat this patient opioids in most of the patient because pain is usually of multifactorial it is having neuropathic component it is having noptic component visceral as well as somatic so we need to give steroids opioids tricyclic antidepressent and Other Drugs like I told you pregabalin Gaba pentin ketamine in different patient every patient you need to optimize and the the treatment so these are few cases where you can see that this is a post radiation loss patient and this is the operated patient so the take home message is that every doctor should know that there is an entity known as neuropathic pain which is very common and in elderly as group the incidence is more and it is a common cause of severe pain and it is can be associated with multiple comorbidities like depression anxiety sleep do orders disability loss of work productivity and you need to treat it and when you can't treat it please refer the patient to the pain physici uh available near to you so freedom of neuropathic pain is everybody's right and I have my painfree India Dr anurag agrawal named YouTube channel as well as a Facebook page where we are trying to increase the awareness about the availability of pain medicine services in our country and I am also very much uh willing to help any of you to come and see our setup at Dr Ramya Institute of Medical Sciences LNO uttar Pradesh bhat to see how we treat our chronic pain patient syndromes so uh apart from that there are two societies of uh chronic pain uh in India that is Indian Society for a study of pain as well as Indian societ of pain clinicians so you can visit their website to find about the latest guidelines treatment options available and about the myses that is the minimally invasive Pain and Spine intervention uh of for all kind of chronic pain syndrome It Started from the trial neuralgia to neuropathic pain to low back pain to prolapse invertible disk to joint pain to arthritis to arthralgia to to uh neurological conditions to spasticity and all these chronic pain problems apart from that at Dr Ram Lya Institute if you are uh from the anesthesiology background interested in pain medicine you are welcome to appear for the multiple DM pain medicine courses FNB pain medicine courses as well as pdcc courses that is post doctoral certificate course of one year duration at multiple institutes including our own Dr Ram man Loya Institute of Medical Sciences lakau uttar Pradesh bhat apart from that you can also come for an observership of 1 2 3 months uh to our Institute if you are interested to see the working of pain medicine team at our Institute so thank you and I wish you all the luck in your life thank [Music] you [Music] [Music] [Music]