What is Neuropathy: Definition, Symptoms, Causes, and Diagnosis

I'm Sara Austin I'm a neurologist here in Austin I'm board-certified in neurology and neuromuscular medicine I'm on the Medical Advisory Committee for the neuropathy alliance of Texas the Medical Advisory Committee wanted to put this video together to educate you a little bit about neuropathy so neuropathy is actually quite common it affects about 20 million Americans one in 15 of us high morothy if you look at this list a total of people with Alzheimer's epilepsy rheumatoid arthritis HIV Parkinson's and MS is only eleven million people so it's very common so the nervous system is really the wiring of your body it sends the impulses from your brain down into your hands in your arms in your legs so when your brain decides to do something it makes everything else work and move the central nervous system for our intents and purposes is your brain and spinal cord the peripheral nervous system is sort of everything else so it's the nerves after they leave the spinal cord and go down into the arms and their legs when a doctor talked about neuropathy when they tell you that you have neuropathy to that doctor what they mean is that your peripheral nerves are damaged when you see a neurologist if you have something wrong in your brain you're obviously damaging your nerves and your brain because your brains made up of nerves as well but to a neurologist when we start talking about neuropathy we mean the peripheral nerves specifically that's what that neuro means nerve and phy means sickness so something's wrong with the nerves and in our world it implies the peripheral nerves so the nerves coming out of your spinal cord going down your arms or legs people use all kinds of words to talk about neuropathy it it means something's wrong with them so they could use the word condition they could use the word disorder they could use the word disease in my mind all of those words mean the same thing it means that something's wrong with the nerves but they're not working the way that they're supposed to sometimes I'll see people and they'll say my hand feels swollen all the time my hand feels numb and it feels swollen but you look at your hand and it's not slowing so you're you're the nerves in your hand or sending the signal that your hand is swollen but you look at it and it's not and so I think it's it's a nerve problem in your hand that's telling you that it's swollen and your brain is interpreting it as your suppose if your hand is swollen but it's not your brain interpreting it wrong it's what the nerves are sending the wrong signal to your brain and your brain telling you something but it's not correct so this is a diagram of a nerve and it's pretty complicated it's got a lot of stuff to be seen on this but the little spindly thing is really the nerve cell body and there's the nucleus there and then all the dendrites and then the nerve cell body has a big long tail called the axon that would be the blue part that comes down and it's the axon is really the wire so nerves really like a wire and it sends the message down the wire and so the message starts at the nerve cell body and then the electrical signal travels down the wire the blue stuff that's surrounding the wire is called a Milan and the myelin is the insulation around the nerve and it enables the nerve to send the impulse faster and so when you lose the myelin or the insulation around the nerve is the nerve can't send the impulse as fast as it used to be able to and sometimes when you lose the myelin like that the whole impulse gets blocked it goes down there and the impulse just can't get through the axon itself can still be alive in that case but that when the myelin is damaged like that the impulse gets blocked so if we look at the top part of the slide that's actually a sensory nerve the bottom slide the bottom nerve is a motor nerve it's the cell body is going to the muscles the top nerve is actually a sensory nerve there's that where that purple square is a sensory is a is a cut out of a skin piece of skin and the impulse is traveling from the piece of skin up the nerve into the spinal cord and then up into the brain so that's how you feel things so if somebody poked the skin or if they touch that piece of skin the impulse would travel up the nerve and into the brain so that you would be able to feel it so there's different types of peripheral nerves and each of them can be involved with different types of neuropathy sometimes you get a neuropathy that involves all the different types of nerves and sometimes you get collective neuropathy that only involves one or two types of nerves and when you see your doctor and they make a diagnosis a lot of times I'll tell my patients you have a specific type of neuropathy so there are the most common types of neuropathy would just be a sensory motor polyneuropathy it would involve all the different types of nerves but there are motor nerves when you think about it they go from your spinal cord down to your muscle they give the impulse from your brain to your spinal cord to your muscle that makes you be able to move and so if those motor nerves get involved they will cause weakness there's sensory nerves and there are several different types of sensory nerves so there's small fiber sensory nerves and then large fiber sensory nerves the large fiber sensory nerves have myelin around them and they tend to carry position sense which gives you your idea of where your joints are in space it also gives you your balance so we when you think about it you can tell when your eyes are closed if all your weight is on your heels or if it's on your toes and that's a very important sensation if you if you don't have that sensation then your balance is really off those those sensations are called large fiber sensations the small fiber nerves carry pain and temperature and so they tend to tell you that somebody's poking you with a pen they'll tell you if you stepped on a tack they'll tell you if you have a cut on your foot you know it hurts really bad and you take care of it till it gets fixed you know basically they'll tell you if you're walking on something hot or real cold so those are small fiber nerves and then lastly there's the autonomic nerves which also is something we don't think about I call them autant automatic nerves basically they control your blood pressure your heart rate your bladder function the most common symptoms of neuropathy the classic symptoms is a stocking glove numbness so you feel numbness and sometimes pain in the distribution of stockings you know of your feet so numbness and pain in your feet and then sometimes it will spread up in your hand then when the motor nerves are mostly involved you'll get weakness and that weakness will often have a lot of cramping so when you try to use the muscles they'll cramp on you very easily and so cramps end up being a big problem so if you have primarily a sensory neuropathy you can have a large fiber sensory neuropathy or a small fiber sensory neuropathy and I'll often make the distinction for my patients but a large fiber sensory neuropathy will impair proprioception it will affect your balance it often won't be painful and there's different causes typically than a small fiber neuropathy but you'll be very prone to Falls small fiber sensory nerves carry pain and temperature predominantly pain tingling is very common burning a feeling of coldness that swelling sensation I was talking about a lot of people tell me they feel like they're walking on stones they they'll describe this hypersensitivity of their feet like like The Princess and the pea it's like you know they can feel a tiny itty bitty grain of sand when they walk on it barefoot and they won't walk barefoot anymore because their feet hurt autonomic systems are often often constipation diarrhea difficulty eating you can have bladder dysfunction that's pretty common with that dry eyes or mouth reduced ability to sweat or heat intolerance so the rapidly can definitely affect your life sometimes it's a minor problem and it causes some numbness in your feet and it really doesn't bother you much but sometimes it does cause trouble so it can affect your balance so it can increase your risk of Falls it can hurt and that causes a lot of trouble so it can affect your sleep so a lot of times it hurts 24/7 all the time so it bothers you during the day when you're trying to walk around and then it bothers you at night when you're to sleep and anything that hurts all the time can cause depression it's something you really can't escape from so that that's a problem too so there's lots of causes of neuropathy too about a third or caused by diabetes about a third we haven't figured out yet so we call that idiopathic and about a third or other causes and we'll talk about those diabetes causes at least five different types of neuropathy it's actually very common no longer you've had diabetes the more likely it is that you get it some people have some kind of predisposition to develop it and I don't know why but they'll actually develop the neuropathy before they're even diagnosed with their diabetes some people have diabetes for years and years and years and get very little neuropathy I don't know why they're so lucky and some people have diabetes that's fairly out of control and they have a really terrible neuropathy it's kind of hard to know who's going to develop the neuropathy and who won't and my advice I always tell people with the diabetic neuropathy once the horse leaves the barn that he's not coming back so once you have a diabetic neuropathy if you decide at that point that it's time to take care of your diabetes that it's really hard to reverse the neuropathy at that point so I always tell people if I can get them early enough I'll kind of warn them it's like you're starting to get a neuropathy don't let it get worse you know take care of your diabetes now because it's really hard to it's near impossible to make that reverse you know if you let it get really bad the inherited neuropathies are actually more common than I think we give them credit for are the genetic neuropathies basically but uh toxins are pretty common so alcohol can cause a neuropathy the heavy metals we used to always test for I think they're actually much less common now than we thought b12 deficiency is is very common and we test for that routinely by roid deficiency is also very common and we also test for that always to make sure that people don't have that the immune system can cause neuropathies they're not very common but when they happen it's a good thing to figure out because they're often treatable so it can cause the most common immune cause neuropathy is probably syidp the chronic inflammatory demyelinating Rafah the-- so there's just a long list of things that could cause neuropathy that should be at least thought about and tested for if it's appropriate and then the last third has idiopathic neuropathy which means we don't know why people have it we're still working on that but there's a fair number of people who have neuropathy and we don't know the cause a lot of people want to know what can I expect in the future I get asked that a lot and that sometimes the answer is I don't know a lot of times the answer is it's usually that you've got this and it's not going to be too much of a problem over time I don't expect that it's going to you know move up or cause a lot of trouble it kind of depends really what type of neuropathy you've got if you have an autoimmune neuropathy and it's not treated it can get much worse and cause you a lot of problems sometimes if you have a hereditary neuropathy chances are you've had it for a very long time and it's going to be very slowly progressive and when you get really really old it might cause you some trouble with your balance and you might need a cane if it started really young in life you know and it's a pretty bad neuropathy it can cause you some problems as you get older it really depends what kind of neuropathy you have and how its progressed you know up until now that usually kind of dictates how it's going to progress over time when the axon is damaged it's a it's hard to grow back so we have never figured out how to really get axons to grow back very well sometimes they can but it's it's kind of an iffy prospect most of the time it grows back about an inch a month is what I tell people it has to grow a really long distance and it's grown in intra month and it's growing to a really small muscle than the chance it can really regrow and come back completely is pretty small when the myelin itself is damaged the myelin the insulation is damaged it can grow back so if you can stop whatever's damaging it it will grow back we don't have any medicines that make nerves regrow so there's a lot of stuff out there that'll tell you there's a lot of health foods and all kinds of things it'll say we're going to make these nerves regrow there's nothing that I know that's been scientifically proven there may be things that help it like I think if you drink heavily that probably doesn't help your nerves regrow if you are diabetic and your diabetes is out of control it probably doesn't help your nerves regrow it's really important that you get a good diagnosis to know what your prognosis is and what to expect and then make sure that everything that's treatable has been ruled out if you think you have a neuropathy the place to start is to see your doctor and let them see what they think and most of the time they'll refer you to a neurologist a neurologist who mostly deal with neuropathy would be the neuromuscular neurologist and so the neuromuscular neurologist know the most about nerve in muscles so your neurologist will do a history and an exam in the history oughta include how long it's been there how long your symptoms have been there what they feel like if you have a family history what medicines you've taken particular if you've had cancer a fever a chemotherapy that kind of thing anyway and then on their exam they'll check your strength they'll do a good sensory exam they'll check your reflexes they'll walk you watch you walk check your balance that kind of stuff those are all things that they should do that would be a standard part of the AGM this slide has a list of some of the blood tests that would be considered when you show up with a neuropathy I would doubt that your neurologist would do all of these blood tests but based on your symptoms and the timeframe of the presentation of your neuropathy these are some of the blood tests that they might consider doing you can kind of read through them the one at the bottom that GGT is a glucose tolerance test that actually is done fairly commonly and so it's um it's where you drink the sugar water and they check your blood over a couple hours to see if you've had the usual rise and fall in your blood sugar to see if you have glucose intolerance these are additional tests that might be considered as well again your neurologist will tailor these tests to your type of neuropathy your neurologist might recommend that you do a nerve conduction study and an EMG I do those frequently for people with neuropathy it tells me a couple of things one it tells me if somebody has a neuropathy it'll tell me how bad it is it'll tell me what type it is so it'll tell me if it's axonal or demyelinating I think it's a very useful test the skin biopsy that like we said before if you have a small fiber neuropathy often the nerve conduction study will be normal and in that case if I really suspect that somebody has a small fiber neuropathy or if I have any question about the diagnosis of the small fiber since we're neuropathy I'll consider doing a skin biopsy to confirm the diagnosis so that's something that we'll do fairly often the spinal tap or lumbar puncture I really only do that if I'm looking for a demyelinating neuropathy like a chronic inflammatory demyelinating polyneuropathy I'll suggest that we do a lumbar puncture looking for elevated CSF protein I hope you found this information useful and that you learn something about neuropathy if you have any more questions feel free to contact the neuropathy alliance of Texas

Channel: Neuropathy Alliance of Texas

Views: 359,858

Keywords: neuropathy, neuropathy diagnosis

Id: NH8UAOMLxV4

Length: 17min 30sec (1050 seconds)

Published: Mon Jun 19 2017