Central sensitisation, pain and the brain

I'm 38 years old. I have had

pain

since I was 10 years old. I was on medication for three weeks of each month, but I was on morphine for 24 hours. I take ibuprofen, polexia, endone, neurofen, Ponce tan, codeine or morphine-based

pain

reliever, so at the worst, I was taking quite a lot of doing and dying, padded morphine patches for taja and lyrica cymbalta and in depth, As if the list were endless, Tramadol because it is slow release. When I was 20, I took a lot of endone, a lot of oxy patterns. because these drugs just didn't touch the sides, I think they potentially saw me and I had drug seeking behavior, fentanyl injections, buprenorphine tablets, so I've been on Doane for about 3 years now, I was 21 and it wasn't until I had a stomach ulcer from excessive use of non-steroidal anti-inflammatories and the doctors finally took me seriously and it was also a kind of wake-up call.

I was prescribed two different antidepressants and anxiety medications, such as Valpo and Era, a Lavar. I was needing to take a handful of pills just to get out of bed in the morning and a test at the Women's Hospital said it could be endo but I think really what happened here is that the endo affected your nerves. I got angry. from me, which is a kind of laser treatment on that nerve that after three types of episodes or sessions of that treatment was very, very effective and has been permanently successful for me, which is really lucky, since I have a bit of a management plan for a pain specialist, if I show up one day they have easy access to this plan so I don't have to wait a long time in excruciating pain, so I got to a point where I was actually out of breath for 12 months, the pain is a lot more manageable than it was, but now it's weird that I take something instead of a panadeine because, well, those are pretty powerful messages, right? and they show the challenges women experienced using a wide range of medications, so I hope to continue. to explain very briefly some of the neuroscience behind why we choose to use some of these medications and hopefully put it into a little bit of context for you, so I'd like to thank Leslie and Phil for inviting me to speak today and I hope it makes sense. because the neuroscience of pain is very complex and can be quite difficult to understand even for those of us in the business, so here we go briefly, we'll just touch on what a definition of pain would look like, how it creates the nervous system. our experience with pain, what changes occur when the pain becomes persistent and then we look a little at some medications that haven't been mentioned so far and gradually I think throughout the day you will get the impression that there is no clear solution .

For each person it's a very individual journey and then we're trying to see where some of these medications fit. The International Association for the Study of Pain defines pain as an experience, it is not simply a sensation, it is not imaginary, it is a response created by the

brain

and it has these elements as a sensory element, so it feels a bit like a sensation, but it also has meaning for us and has these very important emotional elements, so why do we feel pain? It's a response to some type. of danger and that's a very broad definition, danger can come in all kinds of forms, we also have specialized nerves and this process is called a non-cesarean section and it's really those two things together that create our experience of acute pain, so short-term pain We can often say that this happened to me.

I have my warning sign: pain and that will make me go and do something about it. I will tell you that the pain is all in the

brain

and that is not what I mean. that you have made it up or that it is imaginary, but it is the end result of complex processing from the peripheral tissues to many regions of the brain and back down, so if we start with this idea of ​​trauma, some threat and in Endometriosis, for example Of course, if we think about the disease itself, it certainly is a threat to our well-being, it causes bleeding and discomfort and a wide range of other symptoms that make us feel pretty terrible, so it might fit into that kind of internal threat that we have. these specialized nerves that conduct impulses to the

central

nervous system about what's going on in the periphery and endoparticularly these little C fibers seem to be more prolific, getting more of them in the lining of the uterus and probably more in the lesions themselves.

They reach the spinal cord where they connect to the next nerve that goes up the spinal cord to the brain and in the brain it reaches here to this dynamic area that is like a

central

hub like the Central Station, you could call it. and from there we have a whole network of nerves that line up throughout the brain and go to all kinds of different areas trying to locate it so that it goes through this area known as the somatosensory cortex that helps us say well, where is this problem? We may need some of this drive to go up to the motor cortex.

We need to do some activity to get away from it. You will notice that many women curl up into a tight ball. This helps alleviate some of that discomfort. Obviously, we need to mount a stress response we have some kind of danger happening there's a threat to us we need to mount a stress response so that's another specialized area of ​​the brain that comes here to the front of our brain this prefrontal cortex where we try to make sense of it. What does it mean for us? We need to act on it immediately and, as I said, it also has this emotional element and that drags in the memory and the associations of the past, all of that together really creates. descending impulses that come back here and can modify the incoming stimulus here in the spinal cord and this is an important pathway because it is often not as strong as usual when the pain persists, so all of that is a genetic predisposition that we know with the endometriosis.

It can be hereditary, a number of pain syndromes are hereditary, so there is strong genetic inheritance involved, that's something we probably can't do much about. Early life experiences are important because they help hone our stress responses and also teach us how to care for ourselves and past pain experiences influence our current pain experience. Grief is a learned process and therefore depends on our past experiences, so we may or may not be able to do much about all of those things when we look. pain on a particular day in your life going back to that neuroscience idea, how does all this happen?

Those specialized nerves that I was talking about, so this is a representation of the delta fiber and there are also some other fibers that know the beta fibers. this is Alpha Beta Delta, whatever the name is, it was actually related to this insulating sheath here, the myelin sheath, which helps transmit electrical impulses along the nerve, we have specialized nerve endings that can detect things like pressure, temperature and also changes in the acidity of the tissues and Normally in the skin they have particularly specialized nerve endings that, if activated, create an electrical impulse that goes along the nerve, here it reaches this area that is at the level of the spinal cord and finally to the brain, where we can recognize. it's like touch or temperature change or something like that in a similar way with changes in the uterus, the specialized endings there generate a very similar process but we could recognize that or describe it as a cramp can be a discomfort, it doesn't necessarily have to be severe. pain, what happens when things go out of that normal range?

An example would be putting your hand against a hot plate, if you are not too close you notice that it is nice and warm, but if you put your hand too close you are likely to damage your tissues. I'll say, oh, that's painful, it actually activates some of these silent nerves that aren't normally involved in ordinary sensation, what's called the OC scepter or C fiber, and once they activate, they generate electrical impulses that go to the spinal cord. It actually changed the sensitivity of the system and started amplifying what's happening so that when it gets to our brain and is processed, it says this is really important.

You have to pay attention to me. It's not like that anymore, oh yes. I noticed it was a little hot, be careful, tissue damage will occur and this can happen later with other things if the pressure becomes too great with that. Oh, someone's squeezing your arm, oh, you're hurting me, you're done. with a hematoma you have tissue damage, so these are activated when the normal range is exceeded, the same will happen if unusual things happen in the uterus, in the pelvis or in any other tissue, in fact, the nociceptors are activated. they activate and then they start to amplify what's happening in the central nervous system, so nociception is this process of converting the noxious stimulus into an electrical code that activates and enhances or amplifies the system, so I'm not going to explain what is happening at the cellular level.

Dwell too long on this. You've heard of endocannabinoid systems. There are a whole range of other systems. There are different receivers. These NMDA receptors and purr receptors, just to name a couple, we have changes in what happens in the actual way the nerves are. Driving things, those are the ion channels because that's what creates this electrical impulse, but we also have changes in the descending inhibitory control pathways and we get some reductions in what happens there as the pain persists overall, then we have changes in the way the nervous system works. It's working and we end up with this condition called central sensitization which is where we can experience spontaneous activity.

You may have heard people describe a sudden electrical shock. Type of pain that can be spontaneous activity in the nervous system. We obtain a reduced threshold for activation. a lot of people talk about oh, but I have a high pain threshold. I think what is its meaning. They have a high pain tolerance. I have been living with pain for a long time. They just put up with it. This is a change in the threshold, which means everything. That processing is activated more easily because you have that change in sensitivity and what we also see is this idea of ​​a widening of the receptive field, it feels like the pain is spreading and that is because more and more nerves are involved in the nervous system in transmission. those messages so we're amplifying things as the pain persists longer and longer this idea of ​​central sensitization then we have a shift in what's happening here where it was things outside of our normal range that activated our nociceptors and went up. by the system creating the state of hyperalgesia or more sensitivity and we can also develop this situation in which normal things can now trigger that pathway because at the level of the spinal cord there are other small connected nerves that are called interneurons or the nerves themselves develop new ones.

Branches on this sensitized nerve in the spinal cord and which can then easily trigger pain. How many of you have had that sensation of something that you would normally perceive as not causing pain? It causes pain oh yeah a lot of eyesight yeah that's yeah allodynia or hyperalgesia and it's a change in The way the nervous system processes that information is not that simple although we have another player we're learning more and more about the system immune system, so it's not just the nervous system itself, but it's the immune system that gets in on the act. and changing the sensitivity of the system as well, so we see changes here in the peripheral nerves, they create messenger molecules that sensitize this nociceptor and the important area that we are learning more and more about is these specialized cells that they called Gaul.

They are specialized immune cells in the nervous system itself and they seem to be part of the system that is sensitized and activated and acts as memory cells and can change the sensitivity of what happens in themselves. What happens if we do functional magnetic resonance imaging? and we see what happens in the brain itself in a number of chronic pain conditions, we now see these kinds of changes in brain volumes and indications that the brain itself is also changing in response to that continuous input, so the pain syndromes when they persist becomes a type of brain disorder and I would suggest that visceral pain, by this I mean pain that arises from the organs of our body, also becomes a brain disorder, it is no longer localized, It's just the endo problem in the pelvis, it changes everything. it activates the system and that is what makes it so difficult to determine what medication I should take to help control it.

So what do we have? We have glial cells detecting and remembering these danger signals. They can be activated quite easily. We get changes. in nociception, where it is activated more easily and we obtain changes in the brain and, together, that constitutes painpersistent. Returning to what medications can help us, we have heard a little about anti-inflammatories or at least they have been mentioned. We've heard about cannabinoids, they certainly can have a place and we're still trying to figure it out. I think because of what we know now about all these complex receptors, messenger molecules, the way nerves work, we can find drugs that work. on those pathways to affect some kind of improvement or change, so we may want to look for medications that bind to the opioid receptors, we know they are very important, we may want some that block those messenger molecules in the way they that communicate with each other. the nerves, we might want something that changes the way the pupils conduct electrical activity in them, etc., so the thinking is really knowing or understanding what are these various mechanisms that we might be able to make better use of our medications and give a little more sense to what might be useful.

Basically, we want drugs that can work here on the periphery and that's where anti-inflammatories are important. We may want to look at some of the medications that work on the spinal cord itself or those that work on the brain, you've probably tried several of these things that will reduce central sensitization like topiramate Jericho neurontin, they're working to reduce arousal, the others , antidepressants in particular, try to increase that. inhibitory pathways and then some of these newer types of opioids or mixed opioid drugs might do a little bit of both, there are a variety of them that work through a number of different mechanisms and I like to go through them in great detail, happy to talk to people more late.

If you want, but you'll notice here that they have a wide range of effects because they're working on the nervous system and these are the things that limit how those medications can be taken. We know other options. Botox, some of the topicals. creams that compound pharmacists will offset them some of the payments will use intravenous therapies even and of course you want to treat other symptoms, so you could treat irritable bowel syndrome, you could treat bladder pain syndrome and opioids. I'm just going to quickly mention that they have a place, but they can be very problematic.

A long list of side effects if taken intensely. We're also finding that long-term use could even make the pain worse. Research in this area is still developing, but I think that is also the case. Some people's experience, and of course it's already been mentioned that they can actually be quite dangerous in long-term use and at particularly high doses, so in the bigger picture, where do medications fit? It is just one part of a wide range of treatments and each person has to work. figure out what the balance of all those things is for them, so the golden rule looks too golden on the screen.

The golden rule with medications is to start low and build up slowly because these medications can be very powerful and are working on them. your nervous system and have a wide range of side effects, so you want to take the lowest dose possible, maybe a combination will help. There is no easy, clear and simple answer. If you want to know more about your medicines, the national prescribing service has a fantastic website that is independent, it is not a company powered by any particular Barrow. You can find all the medicines on the Australian market on this website and if you want some practical advice on how to use those medicines, we have some fact sheets on the poet.

Pain Foundation website, so that's all I have to say in the short time available. I'd be happy to talk to people in more detail if they'd like.