What is Migraine Aura?

right so let's talk about migraine aura the pictures are all from where i work and where i live in new hampshire and in new england so i thought i would share those with you my migraine itself goes through a series of phases each attack and not everybody gets every phase and there are there's some confusion about the different phases so i wanted to begin by talking about that trying to clarify that if somebody gets all of the phases there's a phase of prodrome uh which also was called premonitory symptoms then a phase of aura then the headache builds from mild to moderate to severe and then there may be a period of rescue if a person takes has taken medication or the headache is terminated and then as most of you are aware there can be a period of days where you don't feel right where there's a post drone as well and each part as i say not everybody experiences every part of this with every attack and the first and really important point to make is that prodrome is not aura prodrome uh can occur in somebody who gets an aura but it can occur without an aura and it can precede the migraine and it um and it can be subtle and it can last for days or it can be rather brief and the kinds of symptoms that people get with prodrome include feeling unwell nausea food cravings some people will think that they're craving for chocolate and they eat chocolate and then they get a migraine and that's actually the chocolate was not the trigger the chocolate was part of the food craving uh changes in emotions uh neck pain and as i say these go hours to days before headache they can be subtle there is by the way in the united states an ongoing randomized placebo-controlled trial of one of the new g-pan medications which are oral anti-cgrp receptor drugs to see whether that g-pant which is called uh eubro japan will actually terminate the prodrome and the aura and the and the migraine which follows so there may be a way to treat prodrome in the past various techniques have been used biofeedback over-the-counter treatments anti-inflammatories there's at least one study that neurotryptin can be useful during prodrome anti-nausea medicines such as dumperdome have been described as effective in in um prodrome and as and we'll find out whether a gpant would work during prodrome but it's kind of a mysterious area prodrome and we know less about it than we know about aura even though i think it may be more common most likely prodrum comes from an area of the brain called the hypothalamus now let's get to what we're really here to talk about which is aura and aura should follow prodrome it usually is before the headache but it can occur during the headache and of course it does not occur in everybody who has migraine and let's kind of look a little more carefully at this there are lots of types of aura and this is the international classification of headache disorders and after it says migraine with without aura everything below that is are different types of aura some of which have new names um and i won't go through every single one of these horus believe me you don't have to worry but i do want to explain about the most common kinds of aura what causes them and what people experience there are six official types of aura within this international classification system visual sensory speecher language motor brain stem and retinal and the most common types of aura last from 5 to 60 minutes and then as i said the the aura is either accompanied by the headache or is followed within an hour by the headache and is linked to the headache although sometimes people will get aura without headache especially older patients so you can have an aura with a migraine you can have an aura with a headache that isn't quite a migraine you can have an aura without a headache you can have a migraine without aura and other times have a migraine with aura and for those who get both types with and without sometimes people wake up with a migraine and don't know that they've had an aura there are other features of aura which i'm going to talk about and there are longer auras and more rare auras which i'll briefly talk about but most important to know although prodrome is common those kind of symptoms that i described are common aura itself only occurs in about 20 to 30 percent of people with migraine and as i said it does not occur with every attack in some people other people will tell me you know i do not get a migraine without an or i always get an or i always get a migraine but i think most people do not get an aura with every single attack and as i said the typical aura and that's actually a term typical aura typical aura lasts five minutes to an hour and is followed by or occurs during the migraine the most common type of visual of of typical aura is visual the next type is called next most common it's typical aura is called any sensory and that's numbness and tingling on one side and in the most common form of that the numbness and tingling moves from the fingers to the hands and up to the lower face and tongue on one side and that's called a cairo oral aura cairo is lim and then the least most common of the typical auras are an alteration of speech or language and it's still typical if somebody gets one of these visual auras for let's say a half an hour and then the next 30 minutes has a numbness and tingling aura and the next 30 minutes as a speech or language aura these can sequence and it's still typical aura typical aura does not cause weakness you can see here from the international classification that the aura the typical aura will have fully reversible that's very important fully reversible visual sensory meaning the numbness tingling and or speech and language symptoms but no weakness and no none of the other symptoms that i'll talk a little bit about so most people when they come to see me they have typical aura and the typical aura is in terms of a visual aura is what we call positive that is people see something it isn't just that they lose vision it's that they actually see something that obscures the vision now people can get negative visual aura people can get tunnel vision people can lose vision and just see blackness but most frequently they do see something it's usually a crescent it it can be zigzags and it gradually spreads across the vision and obscures the vision and this type of aura the most common visual aura is called often called zigzag fortification spectra because this looks like the fortifications of medieval castles uh it's also called teocopsia but it's it's the common type of aura people see this picture of aura they say oh yeah that that that makes sense that's what i experience i'm going to show you a two other auras now that are positive one of them will be flickering so if you're sensitive to the flickering be you may want to close your eyes on this one but you can see the zigzags and you can see the flashing and the flashing is called scintillating scotoma that is a shimmering uh positive visual phenomenon that obscures the vision and then this type of visual visual disturbance will move and obscure more and more of the vision and usually lasts 20 minutes to an hour moving from the visual aura to the hemi sensory aura the chiro-oral aura the person will feel the tingling in the fingers and the numbness in the fingers and then that'll move up in this case move up the left arm the person on the right had it a little bit in the left leg as well and then it goes you can see on the left it goes into the tongue on that side and this person also had a typical visual aura and probably that came first and then the cairo oral aura and you can see the visual aura was uh zigzag fortification spectra and then that was followed by uh cairo oral aura these don't hurt these don't these are not risky and so i don't want to alarm you because they are so common in migraine now the before i get to the hemiplegic aura let me just say that the speech and language aura that can occur when when people are asked well what are you experiencing uh they have difficulty in distinguishing whether the problem is that they have clumsy speech or whether the language itself the content of the languages is altered and it's been so hard to describe this that that's why the international classification sort of said oh we'll just call it speech or language problems because it's a little bit of both and it's very alarming to have your speech or language be disturbed for 20 minutes uh in the setting of a migraine but it is a typical aura now hemiplegic aura is weakness and it's weakness on one side and in order to have a hemiplegic aura by definition the person has to have a typical aura and then get the weakness and they have to have a history of typical aura before they get the weakness that's one way to distinguish for example whether somebody's having a migraine hemiplegic aura from something worrisome like a a word a warning for a stroke somebody who develops a one-sided weakness and then a headache but has no history of migraine or no history of typical aura one would be very worried that that's not migraine on the other hand people with hemiplegic migraine will have a long history of typical aura long history of migraine often they have a family history of this the other aspect of hemiplegic or where people get weak on one side associated with the migraine is that that weakness can last a lot longer than a typical aura a typical aura usually lasts up to 60 minutes hemiplegic aura can go on for days and the weakness can go on for days it is reversible so people do completely recover but it's very alarming and it obviously requires treatment and you can see here on the criteria that the international classification puts in that the that there are two aspects to it there's the fully reversible motor weakness on one side and then the second one is sounds like a typical aura fully reversible visual sensory and or speech or language symptoms lasting the usual amount of time this is much more rare and we take this very seriously and obviously people with hemiplegic aura need a rather urgent treatment there is also brain stem aura and this has had a number of names over the years it used to be called basilar migraine or basilar type migraine or bickerstaff syndrome and brain stem aura again the person has to have a history of typical aura they cannot have weakness and then they have some symptoms that seem to generate from the brain stem such as slurred speech or vertigo or ringing in the ears sensitivity to noise of course can occur in everybody with migraine double vision clumsiness with walking a change in the level of consciousness or awareness and again brain stem aura is more rare we take it very seriously and again people can have these symptoms and not have a history of migraine not have typical aura and then it's probably not migraine aura migraine brain stem aura so brainstem more more rare and definitely requires very significant treatment to help people because it can be very disabling but fortunately rare now moving let's talk about the cause of aura aura is caused by nerves in the brain firing and if the nerves fire in the visual part of the brain then the person sees a visual aura if the nerves fire in the part of the brain which receives sensation they get a hemisensory aura if the nerves fire in the motor part of the brain they get weak on one side and they can fire in a sequence and they can move from one area of the brain to the next and that's why people can have different kinds of aura in a row but the aura itself is related to the nerves in that particular part of the brain firing and we used to think that aura was caused by blood vessel changes that's not true uh it is really caused by the nerves firing and the first man who actually mapped out his aura and you on the left was lashley and he figured out that an aura that this had to move across the brain at a rate of about two to three millimeters per minute and then in laboratory animals it was found that you could induce you could cause the same kind of nerve firing and this was called cortical spreading depression or cortical spreading depolarization or csd and in animals that seemed to move at the same rate as what lashley had described in people now we know that's exactly true that's exactly what happens the nerves fire at a rate of two to three millimeters per minute in the important part of the brain that corresponds to what people see and on the left what you see is um uh is a an area where um the uh the red the ribbon of red is increased blood flow that corresponds to the nerves firing when the nerves fire they have to get more blood flow and then behind that in blue the nerves have have become quiet the aura is related to that blood flow and that firing that has moved across the brain after that they are uh not firing and so there they originally what people saw when they did the experiments was just the nerves not firing that's how it was called spreading depression but in fact it's spreading activation it's spreading depolarization on the right what you see is an actual person at mass general in boston who was in a a functional mri machine and the oxygen consumption in the various parts of the brain was measured and what happened was there was an increase in oxygen flow when the nerves in the visual part of the brain fired and then the oxygen flow went down because the nerves were done firing so the scientists could even see the firing of the nerves the increased blood flow associated with the firing of the nerves the increased oxygen consumption associated with firing of the nerves as this area of the brain fired and then moved on to the next area at a rate of two millimeters three millimeters per minute so that is that's the basis of the visual aura you can see it firing across the visual part of the brain the back of the brain there and that really proved to everybody back in the in 2001 that we actually knew where and how here's another paper from even earlier from 1994 of somebody who was in a pet scanner who said oh i'm getting a migraine and she had a little bit of visual program but not a true aura but it turned out she actually did have an aura and it was occurring on both parts of the brain and the pet scan picked it up she was not in the pet scan for a migraine study she was in for a different study but fortunately these uh doctors who were running the uh the study kept the pet scan on so that you could actually see the cortical spreading depolarization the cortical spreading depression the csd that is the cause of the aura that's the brain in the visual part there firing slowly across time so that explains what fires where it fires and now how does it fire well it fires because generally a and chemical called glutamate which is a chemical neurotransmitter docks with a particular glutamate docking station or receptor this is called the nmda glutamate receptor and most aura is caused by the release of glutamate and then glutamate binds to this docking station and turns on the aura in that particular part of the brain this is not the same neurotransmitter that that we have targeted in most of our migraine drugs but it's quite specific for aura but it is related to our old friends cgrp and as we all know now these new anti-cgrp drugs the monoclonal antibodies can be made against cgrp receptors or against circulating cgrp which you see here in blue or in the united states there are the medicines called g pants which are small molecules that can block the cgrp receptors so we have multiple in the united states we have multiple kinds of medicines that target cgrp very specifically we have seven that have been approved since 2018 and it turns out that cgrp and glutamate are related and that the cgrp can help the glutamate activate the nmda receptor and turn on the aura there's a relationship between the cgrp and the glutamate turning on the aura and what you see in this picture is that when the red glutamate binds to the nmda receptor it's turning on the aura you see the arrow going up into that part of the brain to turn on the aura so there are ways of treating one way that specifically target the nmda receptor one way is to take magnesium and we usually do recommend that people with migraine aura take daily magnesium and sometimes magnesium causes diarrhea so that people can't tolerate it but for people that tolerate it magnesium plugs the nmda receptor so that the glutamate cannot get in there and it can work preventively it can work acutely in treating migraine and aura and it's pretty well tolerated if you don't have a gastrointestinal problem with it and it's safe and it's over the counter so we use a lot of magnesium to treat migraine with aura momentine is also a drug that blocks the nmda receptor that's approved in the united states for the treatment of alzheimer's but it can also prevent migraine and aura because it works a little bit like magnesium it blocks the nmda receptor those are two medicines that are not approved by the united states fda food and drug administration but which we use pretty routinely in treating aura we have other treatments that we do use for aura and if it comes up in the q a i can talk to you about it but these are the simplest ones because they directly address the nmda receptor now some of the commonly used uh prescribed medicines do interfere with that spreading of the neuron of the nerve discharge remember that spreading is called cortical spreading depolarization or cortical spreading depression or csd and topiramate and valprade propranolol and amitriptyline they all interfere with csd with vaporate propranolol and amitriptyline the effect on csd which would prevent aura was observed only after chronic treatment and with higher doses but with topiramate it seemed to block the csd in the aura even after an acute dose one single dose so our old-fashioned medicines that i i don't particularly like and most patients don't particularly like and are not specific they do actually to some extent prevent aura and csd this uh single pulse transcranial magnetic stimulator uh is a device it's called the stms or savvy or sdms mini it's a very simple device it plugs in uh you you uh charge it and then when you put it on the back of the head and press one of those two buttons on either side it pulses a magnet takes that long to pulse and in the united states it's a it's cleared for the acute treatment of migraine so at the beginning of a migraine or an aura a person can pulse it three or four times and that can terminate the auric and terminate the migraine and it's also approved in the uh cleared in the united states for preventing migraine four pulses twice a day and it can be used both ways acutely and preventively and i know of patients in ireland who've been over to london to pick this device up uh and rent it what's really interesting about this device is that it not only prevents migraine but it but when it when you when a person pulses it it stops the csd it stops the cortical spreading depression it stops the aura so it is it specifically stops aura and it specifically can terminate a migraine with aura and then it also works on preventing migraine that's a pretty interesting way to treat because it doesn't involve any drugs and in the u.s it's cleared for ages 12 and above so this is actually one of the treatments that i bring up with patients unfortunately it's quite expensive to to rent in the united states it costs 350 dollars per month to rent so that's a lot of euros and um i really the patients have to be pretty well to do before they can afford it which is really a shame because it's very very useful in treating migraine with aura now again talking about cgrp there is all this interaction between cgrp and glutamate and the brain probably cgrp works mostly outside the brain but in the meninges but the effects of cgrp go into the brain and cgrp uh these monoclonal antibodies such as aranamab and galkanazumab and feminism those monoclonal antibodies do prevent migraine with aura and migraine without aura just as as they prevent both episodic migraine and chronic migraine probably the aura part of it is that relationship that i showed you between the cgrp and the nmda glutamate receptor to summarize this because it's a lot of information the first point is from a diagnosis standpoint to make the diagnosis of the aura the person has to have a reversible neurologic event which lasts from five minutes to an hour if it's just a few flashes of light before that's not it if it's occurring a day before and somebody gets nauseated and neck pain and food cravings that's not aura or as a is a discrete event five to sixty minutes in the typical form visual or speecher language one can have all three and still be a typical aura but only about a quarter of those with migraine get aura and not necessarily with each migraine attack the rare auras involve weakness or other neurologic functions they can last longer than 60 minutes but remember they're always associated with typical aura so if somebody's having those symptoms but doesn't have any history of typical or migraines probably not migraine aura despite what somebody might suggest but the the cause of the aura is the nerves firing in that particular part of the brain and that is is initiated by the activation of the nmda glutamate receptor and the nerves firing in that portion of the brain corresponds with the symptom for example a nerve a set of nerves firing in the visual brain cause the visual aura in the sensory part of the brain the numbness and tingling in the speech or language centers speech or language dysfunction in the motor part of the brain weakness and so on and one way to treat that simple is to try to block that nmda glutamate receptor with magnesium sometimes momenting can be used and these can be helpful in preventing or treating aura there are other treatments that are commonly used that are not officially fda approved in the u.s such as barapamil and anti-epilepsy drugs and we'll try a lot of different aspects the stms device that i showed you can specifically treat aura and it can terminate migraine with aura terminate aura and prevent migraine with and without aura and the anti-cgrp drugs seem to prevent migraine with and without aura which is very good news for people with aura and we've really specifically looked at that but remember aura is not the same as prodrome and then it's really important to make sure that what's going on is typical aura and not something else

Channel: The Migraine Association of Ireland

Views: 29,621

Keywords:

Id: pLd_S_TynoA

Length: 29min 6sec (1746 seconds)

Published: Wed Apr 06 2022