 Welcome everyone. My name is Vanessa Tyler and I'm the local site investigator for the CLSA at Breier Continuing Care and an associate professor in psychology at the University of Ottawa. So I'd like to thank you for attending our May webinar, Long-Term Cognitive Impairment Following Concussion Findings from the Canadian Longitudinal Study on Aging. Before we begin, I want to acknowledge the heartbreaking news out of British Columbia last week and recognize the painful legacy of residential schools and the importance of honoring the 215 children who never returned home from the Kamloops Indian Residential School. I also want to acknowledge that CLSA National Coordinating Centre is located on the traditional territories of the Mississauga and Haudenosaunee nations and within the lands protected by the Dish with One Spoon Wampum Agreement. I'm sending to you all from the University of Ottawa which is situated on the traditional lands of the Algonquin people. We acknowledge their long-standing relationship with this territory which remains unceded. As attendees of this webinar, I encourage you to learn more and to acknowledge the original inhabitants of the lands where we currently have the privilege to research, live, and work wherever that may be. It's now my pleasure to introduce today's webinar entitled Long-Term Cognitive Impairment Following Concussion Findings from the CLSA presented by my PhD student Mark Bedard. So Mark holds a BA in Psychology and MSE in Neuroscience from Carlton University and he's currently a PhD candidate just finishing up in Clinical Psychology at the University of Ottawa where he's working toward developing competency in both clinical psychology and clinical neuropsychology. And Mark is a Vanie scholar supported by the CI Char and his doctoral research examined long-term impact and cognitive function following concussion. He's published a number of articles in peer review journals and presented his work at international conferences and his pre-doctoral research examined the impact of chemotherapy treatments on cognitive function in breast cancer survivors. So now it is my great pleasure to pass it along to Mark. Wonderful. Thank you very much. It's so great to meet everyone here. It's a huge pleasure to be able to be at this point to share with you some of the findings from my dissertation which I'm very fortunate to have defended back in February. Ultimately too I think a great opportunity to showcase what the CLSA can be used towards so how some of the data can actually be leveraged in a way and what findings we can have come from it. I approached some of the data from a very interesting angle. I've always had a large interest in looking at long-term functioning following concussion. I've had a couple in my past. I've known some people that have had some different head injuries and so one of the big questions that I had was does a concussion lead to long-term impacts as far as cognitive functioning and ultimately as we get older right do you know what does this mean for long-term aging. So these were some of the questions that I was wrestling with with my dissertation. Let's see so I don't know if I have access surely to the slides. Do I need to get good to go you have access. There we go okay so I guess I just have to click I can't use my keyboard. So first thing I just did a bit of a cursory look at some of the epidemiology around TBI so traumatic brain injuries in general and they seem to be a really big phenomenon for younger Canadians younger individuals tend to come on as well in that sort of younger adulthood where you know people are starting to engage in sports they might be driving for the first time kind of really busy lifestyles and then beyond that they seem to be a phenomenon in older age where balance and the ability to ambulate is a little bit more challenging certainly in you know the Canadian context of winters with ice lots of hazards at play and so with the increasing frailty that we might experience in older age it seems to be an area in an area in life when people are having head injuries. So these are you know pretty common affairs in fact many of us may have you know had a head injury in our past and so it's a really important research question as far as looking at the the long-term impacts of head injury and what this might mean as we get older. Ultimately what I was most curious in is you know what we call concussion but the research literature calls mild traumatic brain injury so MTBI and so really it's on the lower end of head injuries so where we might have had some kind of unconsciousness but it didn't take up very much time less than 30 minutes might have had some kind of amnesia like difficulty remembering events in and around the head injury might have some kind of altered mental status some kind of like neurological deficit so maybe a sensitivity to light or to smell these kinds of things and ultimately you know if if someone is presented to hospital they would use the Glasgow Coma scale score so scale scores are 13 or higher which means that the person you know is pretty aware they can respond to questions you know as far as their sort of consciousness when they get to hospital it's there no real difficulties with that. Now here's the thing research literature examining long-term cognitive you know impacts of concussion or sorry a traumatic brain injury have mostly looked at more modern and severe traumatic brain injuries so there's a huge amount of literature out there that is examined you know these types of individuals who may have been unconscious for a day or two in hospital for longer periods of time and so the big piece of the puzzle was was missing as far as looking at the long-term impacts of mild traumatic brain injuries which were actually one of the most more common types of head injuries um so I was really interested in this and you know ultimately when when when we look at some of the the neuroimaging findings around mild traumatic brain injuries we're talking about changes in the frontal part of the brain so this part of the brain is really important for personality parts of it are important for our ability to you know be awake and to have some some level of consciousness and a big piece around the frontal part of the brain too is it acts as like an executive you know over overriding control on on general cognitive functions so it's really it's a really important area of the brain as far as cognitive functioning is concerned and so when we have a concussion just very generally kind of cursory overlook on it we might have some kind of impact possibly some kind of rotational forces if the person is spinning but ultimately what we're talking about is is changes on more of the microscopic level where we might have brain cells or the cell body and this kind of longer axon this like tail that then connects with other brain cells and you know the brain's got a lot of brain cells we're talking about a hundred billion neurons a hundred billion brain cells um but what can happen after a concussion is that some of these brain cells the fatty part of that tail that really helps with the communication can shear so this is axonal shearing and this is really common after um someone experiences a maltraumatic brain injury and especially so when they've experienced an mtbi with loss of consciousness and so this is what some of the the imaging studies have shown is that we'll find some axonal shearing and we'll find some changes in frontal parts of the brain so what does this mean uh well the frontal part of the brain as I mentioned is really there is this kind of like overriding um you know control center for a lot of cognitive functionings and when we start talking at that level we're really talking about executive functioning ability to plan to organize to problem solve to inhibit responses like impulse control um set shifting this is kind of that multi um multitasking kind of piece can we switch between different things flexibly are we a little bit more rigid and get stuck if the you know the whatever the environment we find ourselves in changes can we adapt um and these kinds of executive functions are really important for what's called prospective memory so this is our ability to remember to remember so the fact that we all knew that we had this webinar and to organize ourselves to be here to attend it and so when we talk about prospective memory we can really break it down as far as how is it that we remember to remember and so sometimes this can be event based in which case there's some kind of external queue so maybe this is like a calendar reminder or it could be a little bit more time-based which is more self-initiated so we don't necessarily have that external queue but we rely on internal queues to try to remind ourselves that we we have to do something um and so it's more time and and uh and cognitively intensive it tasks more on to the executive functions um looking out though as far as what cognitive functioning uh is following mtbi there have been a lot of different research studies uh really more recently um and a few meta analyses that have you know cataloged these kinds of things so meta analyses to make sense uh of what the overarching literature tends to show some of those early meta analyses though were saying that people tend to get better right around three months so if you have a head injury if you have a concussion give it some time and you know if you look again in three months odds are you should be back to normal um but what some of the more recent meta analyses are suggesting is that those earlier meta analyses were actually just obscuring a small subset of people that tend to actually continue to have impairment long after the head injury and um so this was really interesting you know it's maybe not the case that everyone who has had a concussion will have long-term changes and long-term impairment but there are certainly a group of people that do and so what's different about them and so this is where I was really intrigued so uh clsa a really wonderful reservoir of data of course it's longitudinal assessing individuals between the ages of 45 and 85 every three years and for these 20 years and there are those two assessment streams tracking more of that telephone follow-up and comprehensive um where uh individuals are followed uh at 11 data collection sites across Canada and so there's more of an in-person aspect extensive assessment biological samples and in my case which I which I was really excited by is that there's some neuropsychological testing as well that happens um I was also fortunate for my dissertation to have access to both the baseline data that first wave and the second wave follow-up data so um when I go in to start talking about what my research looked like um I have a couple studies and so some are focused more on the baseline and there'll be a third study that that focuses on uh on that follow-up as well so as far as my primary measures um sort of background information was looking at age sex gender education which I had recoded for more of an international readership and publication um so I I recoded the the education to kind of fall within those sorts of categories um also had access to the brief traumatic brain injury screen which includes a lot of different items within it but most of most interest to me was this loss of consciousness uh variable and so they categorize it based on these three different levels um obviously when we're talking about mild traumatic brain injuries some of these individuals will fall in this greater than 20 minutes but also um it could be it could also include some of those more moderate to severe so we did exclude these individuals um and really just focused on the one to 20 minutes unconscious and less than one minute unconscious um looked at depression as well so the CESD is a really useful scale it's it's often used in research to look at and and make sense of depressive experiences um and uh testing language so whether individuals were tested on those neuropsychological tests in in English or in French um I also looked at alcohol frequencies so there's a variable within the CLSA that that looks at alcohol um a couple others as well but these were the primary ones those are the ones that I was most interested in as far as um the neuropsychological aspect um the CLSA uses the Miami prospective memory test so there are two different tasks one more event-based the other more time-based so with the event-based one the examiner prompts the participant um to then reach over to an envelope where the the examinee the participant will will have to their their tasks with giving the examiner from that envelope with a bunch of different bills a five dollar bill and to keep a ten dollar bill so there's an envelope with a bunch of different denominations they have to remember to do this and it happens you know some minutes after they start the cognitive testing and then 15 minutes after the this test is started they also have to self-initiate this time-based activity to grab an envelope with a bunch of different numbered playing cards and select the the number 17 to hand this to um to the examiner so there's some different aspects of of this prospective memory task and ultimately it's scored based on three different facets or or aspects um the intention to perform did they actually remember that they were supposed to do something accuracy did they remember what it was that they were supposed to do and need for reminders like did they really need some help to remember that they needed to do something in the first place and so ultimately these um for each event-based each time-based each one of these is scored on three so a total of nine points for event nine points for time-based um as far as other executive functioning or other cognitive measures we had the controlled oral word association test fas um examiny needs to say as many words that come to mind within like a 60 second period for each of those letters animal fluency examiny needs to identify and name out as quickly as it can the all the animals that come to mind mental alternation tests the the examinee is flipping between an increasing sequence numbers and letters up the alphabet up the number chain jumping back and forth so a lot of set shifting with this one and the stoop test really interesting test of inhibition and flexibility feel free to look that one up online it's really cool and then we had some tests of long-term memory as well so the ray auditory verbal learning test um so asking uh telling the examinee um I think 15 words reading them out and then having the examinee repeat as many of those 15 words that they can so one's done right after presentation the other one's done some minutes later as more of a delayed recall okay um so as I mentioned really interested in looking at the mild traumatic brain injury piece we did exclude people that had some kind of neurological disease uh Alzheimer's multiple sclerosis Parkinson's central nervous system cancers stroke transient ischemic attack which is like a mini stroke any brain injury or multiple injuries which can include brain injury in the past 12 months these people were excluded as well um and any missingness so we did a list wise deletion on any missingness across the data set so ultimately what we had were people with mtbi that had some kind of brain injury a head injury um more than 12 months ago with a loss of consciousness um and really only looked at people that had only one head injury one brain injury um so isolating for a single lifetime concussion that occurred more than a year ago and as I mentioned we removed the people that had reported potentially long loss of consciousness so ultimately this was our this was our distilled baseline sample um so quite a sizable sample to work with which I was really excited by um ultimately in this first study looking at the baseline data really interested in looking at that prospective memory test right so it's really sensitive to to to changes in executive functioning executive functioning being subserved by the frontal lobe which we know that those neuro imaging studies tend to show some changes in um so I ran a repeated measures and cova um to look at group differences on that prospective memory test and I controlled for age education sex depression alcohol frequency testing language so trying to remove some of those other confounding variables ultimately to distill whether you know having had an mtbi with loss of consciousness in the past means that we're maybe predisposed or more likely to experience some kinds of deficits in prospective memory um and so you know we also had some additional analysis as part of that repeated measures and cova to really break it down to understand is that if there are some changes is it more in that time based or more the event based functioning um and then beyond that right so I talked about those meta analyses and it seems to be like a subgroup of people that tend to have impairment so I ran um some some pretty interesting analyses to really break it down so that we can isolate people that we would consider more impaired um and so by that it's scoring two or more standard deviations below the mean of the control group for that time and event based uh prospective memory functioning task so we're talking about like you know we're not just saying like people that have made like a mistake they're the like significant mistakes um so they're really quite markedly you know at a deficit as compared to the compare group comparison group okay um a lot of data here that I presented but ultimately to say that the you know each of these different groups were largely the same um uh some differences popped up in depression so controls were generally speaking reported less depression the other two groups well we can see here that the means are relatively close standard deviations are also pretty close so not super you know not not a not a huge effect here but the controls did have a larger proportion of females as a relative to males the inverse was found for the the other two groups so at any rate we did control for these factors but these you know these are important pieces to keep in mind when when making sense of the results um so this is a table that you know really highlights the results from that repeated measures and cova and from those you know two standard deviation impairment rate analyses so ultimately what we have here are some um small but significant changes as far as time-based functioning is concerned so really popping up for those that reported um either sets of unconsciousness so ultimately people that have had an mtbi more than a year ago that reports and loss of consciousness in this study tended to score lower on the time-based um measure of the of the my of that prospective memory task um that wasn't found for the event-based functioning and when we look at the errors it seemed to pop up more with the intention to perform so a failure in their in their ability to remember to remember to do something it's not that they forgot what it is that they were supposed to do um there was just a breakdown in that process in that self-initiated process to get to them to the point where they can you know actually grab that envelope um and and grab the items and hand it to the examiner work i really interesting though is when we looked at the impairment rates right so scoring two or more standard deviations below the mean of the control group um really it's this group that reported more loss of consciousness that were quite a bit more likely to be impaired on time-based functioning relative to those who reported less unconsciousness and certainly less than the time or than the control group and we're talking almost like 50 more likely it's quite a quite a striking um difference that's emerged there um so this study was really interesting this was the first one that i worked on with clsa data really excited by those findings and then i really wanted to see okay so prospective memory we know is super influenced by executive functioning but what processes in executive functioning tend to be more impaired or more implicated in mtbi and again let's look at you know the declarative memory let's look at that long-term memory piece let's have a look at whether you know people's verbal long-term memory seems to be you know implicated at all as well so that was the focus of my second study um so as far as analyses um a multivariate uh analysis of covariance so looking at the relation across all those different cognitive um tests again controlling for age education sex depression alcohol testing language same covariance as before and i also ran some different impairment analyses this time uh you know scoring one and a half or more standard deviations below that control group which we had adjusted for age and education and ultimately chose a more uh liberal standard deviation this time because i did some further analyses to group up those different test scores um as people have also done in the case of like mild cognitive impairment if you're at all done or have looked at that kind of research um might end up looking at a couple of different tests um to see if it's more like scoring at that level of impairment on two or more different tests so to really kind of hammer home that we're talking about someone who has um a pretty consistent level of impairment um and i broke it down based on you know two levels of impairments or two domains so grouped up the executive functioning tests and those two um tests of declarative memory of long-term memory so ultimately trying to see whether people tend to be more impaired on individual tests of executive functioning and verbal memory or if we group them up does there tend to be like a more consistent picture of impairment and is it more one or the other so uh as far as the results from that second study um again we have the results here i've broken it down based on domain so results from that man cova here and then as well here when we look at the raw scores ultimately um not really any significant changes on that group yeah group mean level and i think this is this is consistent with what the um with what those earlier meta-analyses would say when we have grouped level mean changes we don't tend to really find a lot of difference a slight difference here as a bit of an anomaly as far as the um the group with the lower the the the less amount of loss of consciousness tending to score a little bit higher on this animal fluency test um for for you know an interesting reason i'm not even quite sure what what explains this but you know we're also talking about really small effect sizes so it's not super meaningful um in the larger scope of things generally speaking these groups are even though significant at the p level um you know meaningfulness um it's not exactly there however um what does seem to be there from both the p level and meaningful on the effect size piece of things uh are these impairment analyses so um the group that reported more loss of consciousness why it a bit more impaired on that verbal learning test the declarative memory um and and we're talking here like you know a little bit under twice as much um so it's it's quite a big change as compared to the control group and the the the less than one minute group where we also found some significant significant differences again with this you know more uh loss of consciousness group uh was in the mental alternation test so that's that test where they had to jump between a number and a letter up in sequence uh as many times as they can within a minute so actually a little bit of a challenging task requires a lot of efficiency and set shifting um and that verbal fluency task you know recalling as many words they can that begin at the letter f and s within 60 seconds as quickly as they can as many as they can um so these two domains of executive functioning these two processes in executive functioning seem to be areas of a particular impairment um in that higher loss of consciousness group as compared to the lower loss of consciousness group and that control group when we break it down or group it into that two test impairment again the same sort of picture um shows up um for my third study I'm going to just present some abbreviated findings we did also do some other stuff to look at um you know aspects of cognitive reserve which is a really neat area of the literature um I thought I would keep this presentation a little bit shorter so I'm I'm admitting that um but you're more than welcome to have a look at the original source article if you have access to it um because cognitive reserve um is this really cool area of the research that is really coming and taking um uh it's coming you know it's becoming really popular um so aspects either of our lived environment or maybe of our like formal education um that might actually help protect against and buffer against increasing age or you know increasing brain pathology so in the case of like a traumatic brain injury um in the case of any kind of like central nervous system changes like neurological deficits from Alzheimer's and Parkinson's cognitive reserve is is really quite quite huge in in in in those areas but I've left it out here um just to keep it on on cognitive functioning a little bit more um precisely but I'm more than happy to talk about that those results too if there's any questions um what I wanted to do in this third study um with the second wave data is to understand whether so from the the first two studies we know that there's a small group of people that tend to have long-term deficits in executive functioning and in some cases in in verbal memory as well um so we have this group of people but what does it mean in the larger scope of mtbi when we look again three years later do people tend to get better uh does cognitive functioning deteriorate or do they tend to stay the same um so this is what I was really kind of focusing on um there's been some you know look at the some some research studies have found that um you know head injuries particularly more um severe head injuries might actually predispose or start a cascade of brain changes that can initiate a cognitive deterioration towards in in some cases dementia but certainly um you know more of a longer term change on the negative end as far as cognitive performance um so I was really interested in looking at whether a single head injury with some level of loss of consciousness um might actually lead to any kind of change in the longer term should we actually be concerned for some of these people that that are reporting some significant differences um what does it mean um so that's why I use the reliable change in disease I'll talk a little bit more about that because it's um a really cool analysis that you can run when you've got you know pre and post or wave one wave two um ultimately what a reliable change index does is to try to understand whether a second set of scores is reliably different or significantly different from a first set of analyses accounting for measurement error so the fact that you know if I were to ask you to uh recall as many Canadian Prime Ministers as you can um that you're probably going to have a different number today versus if I were to ask you in like a week um so there's always a bit of measurement error and the reliable change in disease can help protect against that um and also protect against the fact of or the effect of practice effects so naturally when you're more familiar when you've done something once it's going to be easier the second time around and so this kind of thing in cognitive functioning is is super well documented um but the reliable change in disease can help protect against some of these influences so ultimately to have a little bit more of an assertion that if we see a change at time two it's because time two scores really are different um from time one um and so how we um how we categorize that improvement or decline in the RCI literature is to take a z score of um 1.645 plus or minus so if they fall between these two you know sort of cutoffs then then we can say it's no change but scoring greater than 1.645 means that there's some kind of improvement scoring less than the negative it says that there's a reliable decline so this is what that equation looks like essentially each participant will have had you know their first test scores and their second test scores so taking uh the difference between the two and then also subtracting the mean of that second uh of of the entire group at the second test uh time minus the mean at the first test taking time and then dividing it by the standard error of the difference so a standard deviation of the difference between these two means um and ultimately this allows us to remove the influence of practice effects and it allows us to remove the influence of um of of measurement error um so it's not just a simple case of um of you know seeing that maybe this time two score is lower than the time one but it's not do it's it's more than that um it's beyond what people generally tend to have as far as their you know second time point score relative to their first time point score uh and again we're talking about you know some pretty big changes so to reliably say that there's some improvement means that the person at t2 would have really outperformed their t1 uh scores and likewise with decline really did significantly worse the second time around as compared to the first time relative to what the you know average amount of change would be found across the sample and this mean two mean one this is of the control group as with the standard error difference when I um graph out the reliable change scores so this is before I've categorized impairment and decline this is uh what it's looked like and this sort of darker hashed off um these bars here are for those that have had loss of consciousness one to 20 minutes the striped lighter one is for loss of consciousness less than one minute and what's super faint and hard to see are just super black small error bars or and bars right along the zero line that's the control group so which makes sense the control group ought to not have a whole lot of change um they are the index upon which we are comparing the two other groups to and so on the left side if the bar is jetting out closer into the negatives obviously you know it suggests that people tend to perform worse at the second time point relative to the first whereas if we start seeing some bars popping up on the right side they tended to do a little bit better the second time around as compared to the first and I have this you know these error bars around um these these point scores here to just kind of show where you know most of the people tended to fall um so where I was really being pulled towards um so some interesting findings um you know in the case of loss of consciousness one to 20 minutes that's a bit of a mixed bag um but um we also have to acknowledge that we haven't done that impairment rate yet and so although it's the case that in some cases people tend to deteriorate other people tend to improve um what is this actually is this a real significant change relative to the control group and and likewise if we were to like hone down to uh a small subset of people that have improved versus a small subset of people that have declined um you know it is that really a big change or a big difference uh as compared to the control group so that's what the this next set this next table here demonstrates um so I did also run some additional analyses looking at time one time two scores not a heck of a lot of change on that group mean level analysis um and so I also present that here for the declarative memory again breaking it down by cognitive domain but it does get interesting when we start to look at the impairments and the improved so after calculating those z scores and really dichotomizing participants into um into either improved or deteriorated or no change and so here I'm presenting that the dichotomy between improved uh sorry on the left side you'll see declined and on the right side you'll see improved um reliably so um the only ones that really came up the significant uh were in the group that reported more loss of consciousness and um in a couple areas it was really just declined so significant decline in the mental alternation test as compared to the two other groups which didn't differ from each other uh and in animal fluency again compared to the two other groups and so when we when I categorize sort of a global decline versus improvement so just looking across all the different tests if they declined on two or more tests or improved on two or more tests I gained that same story came out um the people that reported more loss of consciousness were more likely to have exhibited decline uh relative uh to the two other groups so so 10 of people that have had a single head injury with not a lot of loss of consciousness one to 20 minutes um you know three years after that first assessment tended to get worse there tended to be some deterioration so as far as what my dissertation is showing um is that of course mtbi's are really common um it's common that any one of us of the you know 60 people that are in here today um might end up having a head injury in the near term but um I think it's important to recognize that although most people will improve and get back to back to normal after a few months there are a small group of people that tend to have lingering difficulties that tend to continue to suffer as far as their cognitive functioning is concerned and what this seems to be the case for are those people that report loss of consciousness and particularly when there's more loss of consciousness um so we found that there was lower time-based prospective memory functioning um at some point after you know a year later at least a year later um those errors tended to indicate that it was more about a difficulty to remember to remember that longer time loss of consciousness tends to be most implicated or most most likely a candidate there's something going on with these folks um that there's also the case of you know deficits and verbal memory long-term verbal memory uh and then these aspects of cognitive control and set shifting right that mental alternation past when we look at a three-year window and we look again three years later um right that that 10 percent of people on sort of globally index cognitive functioning do do show some deterioration so there's there's something to be said about mild traumatic brain injuries um that it's it's not just uh you know get back up and get back and play um in the case of a sports injury um it really is something to to be careful about and to try to understand a little bit more um certainly in the case of uh of people who might be you know working and and needing to manage a lot in their day-to-day lives but there's something to be said too about what it means for us as we as we age um and so to be aware of this and um so some of this research I think has some you know real-world applications for primary care um but also to to help inform the the next set of researchers um who can take this um that next step forward um and so to understand a little bit more about what it is that these people what it is about these these people um that might help to you know flush out the deterioration versus improvement uh and what kinds of things can we do to help support these people um so ultimately um it's nothing that we necessarily need to be concerned of as Canadians who tend to have head injuries from time to time as with the rest of the world um but to recognize that there are going to be a small group of people that might complain about some difficulties in their cognitive functioning and not to dismiss those concerns that they are real that there are a small group of people that have difficulties and so to recognize that to be so okay well thank you very much I'd love to open this up for any questions if you have any um I am happy to answer questions either about um my profession in clinical psychology clinical neuropsychology about the data about the results um anything at all okay thank you very much Mark for your excellent presentation so uh as Mark said we will open it up for questions now and I just want to remind you that uh your muting will remain on so if you have questions or comments feel free to enter them into the chat box in the bottom right corner and I will read them out uh in the order in which they appear and then Mark will have a chance to answer them so feel free to share any questions I didn't actually get a I don't know if you're getting some questions uh Dr. Taylor but I did get one sent to me privately okay so I will give a little reminder that's great if you want to read that out Mark and if you guys could uh share them make sure that you set it to everyone and then I will read them out and that way everybody will be able to to see what the questions are but go ahead Mark if you want to tell us what what the first question is you got sure sure happy to so uh I did get in a question here asking what were the etiologies of the TBI's balls and VA's etc and were litigants excluded sorry to close this uh poll yeah I think I'll enter the question um so yeah great great question right so um you know obviously when we when we start talking about litigious context we might start talking about people who are concerned about secondary gain are they actually giving you know good responses or are they trying to present themselves in a particular way because of court or money and these kinds of things so CLSA um you know we're really talking about people that aren't coming in with like a set agenda uh it's really you know we're talking about people that are that are being followed as part of this huge data set um so um we don't have data on litigious status um so we didn't exclude these kinds of individuals but I think it's also safe to assume that the people that participated in the CLSA weren't doing so for secondary gain as a part of you know litigious means if we will um as far as the falls the etiologies so it really is split a big part of this is falls naturally we're talking about older adults you know those between the ages of 45 and 85 mean age across the three different groups was like 60 61 so it's a big part of the head injury um sports related was a big one um and vehicle collisions as well um and you know the thing is what we what we have is a limitation in front of us is we don't know when the head injury occurred so we don't know how old they were we just know that it happened at least a year ago um but uh great great question hopefully I've answered it uh to your satisfaction uh thanks max so the next question is from alexandra fiorcho who asks uh if you could uh mention whether you examined sex differences in these associations yeah not uh not explicitly um but I did do some secondary analyses um so so if you were to find the source articles through pub med let's say um we don't break down the groups and look at you know the impact of of sex um but I did do some some other analyses sort of on the side um generally speaking no um you know there wasn't really a big impact of of one sex versus the other uh although I think there was a bit of an association of females tending to exhibit a little bit more deterioration relative to males um but um you know this is we're also relying on my memory which is terrible and um and I think it was it was a very small association uh great thank you and then uh next is the question about persistent depression following tbi so does mental health deteriorate or improve after three years ooh okay great question yeah I can't answer that second one unfortunately um you know people so we did have those depressive scores for the most part um you know we're talking across the three different groups right so um you know a lot of a lot of what I can talk about will get washed out in group level analyses so people tended to have some depressive symptoms um but generally speaking on a whole on a mean level analysis people weren't depressed but certainly people within those groups are going to have been depressed um notably you know and this is with the CSD it's it's more like recent recall of depressive experiences so um as far as answering that second part of the question you know does mental health deteriorate uh or improve after three years hard to say excellent question um and I and I think this this could be a really interesting you know research topic to flush out um you know certainly for anyone that might be interested um clinically I do fall between the two sort of domains um so it's well within my willhouse I just don't have the answer unfortunately um and persistent depression um I I haven't looked into that um only because I was limited based on the measures at my disposal um so the CSD is really looking at more recent um depressive experiences um the CLSA does have a whole trove of questions and variables to look at mental health um so again I think it's you know a wonderful research question to to begin to try to understand great thank you and any other questions from our audience we have a few more minutes left in the in the webinar okay um so I guess if there aren't further questions uh maybe we uh we can wrap this up you've muted yourself Mark so uh um I'll give you a minute I know sometimes it takes a minute to type a question in so in the meantime I will mention to everyone I'll give you a reminder that the uh the CLSA data access request applications are ongoing so um I surely just shared in the chat with you the link to learn more about the data access process and the next uh the next deadline for application is September 8th uh 2021 um and I would just like to remind everyone also to complete the survey located under the polling option so in the bottom right you have participants chat and then a new option appeared of polling so under there is your survey of how the webinar was for you so if you could take a couple minutes to fill that out that would be wonderful I'd like to thank Mark very much for the um for uh participating in the webinar series it's very appreciated and I know you're very busy at the moment so I uh appreciate you taking the time to prepare and uh and uh share your very interesting results with us and I would like to remind you also that there's one more CLSA webinar this season so it will take place in June and it's going to focus on data and linkage and if you go to the uh the webinar's part of the CLSA website details and registration information will be posted soon and we invite you those of you who uh who use twitter uh just a reminder that this webinar series is pro uh is promoted using the hashtag CLSA webinar and you're invited to follow CLSA on twitter at at CLSA underscore ELCB so thank you so much everybody for um for uh attending the webinar and we hope oh there's oh there's a question uh I'm sorry I missed it I missed this question one more for you Mark you thought you're off the hook and I wonder whether you compared anxiety and mood symptoms in the RCI study so I think you sort of answered that but if you could maybe just uh just read yeah no no no great great question so uh no I I didn't um but uh yeah you know it's uh it's one of those things that you know as you develop the RCI you've got an index based on uh improved versus deteriorated so you could certainly run like a logistic regression um to look at uh whether you know some of those anxiety those mood symptoms uh implicate in you know whether someone maybe gets better or deteriorates and has worse cognitive functioning um I didn't um just because we had a you know we're talking about 10 of the people that tended to deteriorate so it's not actually a huge sample and so I didn't have a lot of power to play with so I wanted to keep some of my other analyses you're talking about um you know cognitive reserve pretty pretty focused on my research questions which I was looking at social support so not unrelated to mood and anxiety as I'm sure we can all you know um have some awareness of in this in this pandemic and this lockdown so um yeah uh indirectly I can certainly comment that likely I think there's something to be said there um but I can't definitively lots of opportunities for for trainees to do studies to do research on this okay so uh thank you very much to everybody and I wish you a wonderful rest of your day and I guess we'll see hopefully most of you in June for the the upcoming webinar thanks all great thank you very much take care everyone