Note: The below is a summary transcript of the conversation. View the video or listen on Soundcloud for the full discussion.
1. Can you explain neuro fatigue? What exactly is happening in the brain when things get confusing or slowed down in the brain?
We don’t understand neuro-fatigue 100%, but one of the leading theories right now is regarding the multiple networks in the brain – certain things inside your brain when you’re concerned with performing a task. If you have a task at hand that’s done by a network inside your brain, called the “executive network,” and when you’re just kind of daydreaming not really doing much, the dominant network in your brain is called the “default mode network.”
What usually happens in a normal person’s brain is that the “default mode” network is activated most the time when you’re just going about your day, but when you have a task at hand – if you’re going to do a math test or if you had to do something specifically – you would default over, or switch over to the “executive network.”
Moving between those two networks is what you need to be able to do in order to have cognitive thought processing, and in order to minimize the amount of activity in your brain.
When we look at people that have high stress or people that have anxiety, and when we look at people that have concussion (or persistent concussion symptoms), what we find when we put them into fMRI scanners is that both default mode network and executive network are activated at the same time.
What this does is creates a more difficult situation, and when you’re trying to perform a task your default mode network is taking over, so you’re not able to move between the networks easily. You have both activated at the same time. This becomes confusing for the individual and they can’t concentrate properly. But, because you’re activating more areas of your brain, you’re actually burning more energy and you become more fatigued as a result.
That’s the leading theory right now on neuro fatigue. Now, the question is how can we then change that? Is there a way in which we can change that and get people better at using their executive network? And, turning off their default mode network when they have a task at hand, so that they’re not doubling up their brain power, and therefore, going through neuro fatigue. That’s a whole other question.
2. I noticed that CCMI has a 10-day RTP protocol, but we currently use a 5-day protocol for our athletes. Do you feel like a 5-day protocol is adequate for our situation considering we cannot make educational accommodations for our patients?
We have a 10-day protocol – and not even a 10-day protocol – we have a 10 step protocol. That’s a huge distinction to make. We’re not concerned with the number of days in your protocol; we’re concerned with the number of steps.
So, let’s change 5 days to 5 steps. Is that adequate? According to the international consensus statement, the return to play process is a 6-step return to play. If you look at the return to learn process, it’s a 4-step return to learn. When you’re dealing with adolescents, the recommendation from Davis et al in 2017 – which was a systematic review that helped to inform the Berlin consensus document – said that return to learn should be completed before a return to play is initiated.
Therefore, what you end up with is a 4-step return to learn, and a 6-step return to play. And, what you get is a 10 step protocol. That’s all we’ve done in our protocol: put the return to learn in front of the return to play to put more steps into the process.
The reason that we’ve done that – and the reason that other people are calling for that – is that just relying on symptoms for an individual is inadequate. The brain takes longer to recover from a metabolic or functional standpoint than it does for the symptoms to go away.
Just because the symptoms have gone away, and you’ve passed a 5-step protocol (which you could theoretically get done in 5 days) is definitely inadequate because the research has shown that the human brain takes between 3 to 6 weeks to recover appropriately.
When you’re just relying on getting through your 5-day step, yes that is definitely inadequate. You should be adding more steps into the process and you should also be trying to add some objectivity to it such as physical exertion testing; baseline pre and post injury testing in order to try and truly understand when somebody’s metabolic recovery time has elapsed.
3. I have 2 elderly patients that all have dizziness and fatigue as their main symptom. Due to this population being super rigid into extension, how can I test for benign paroxysmal positional vertigo (BPPV)?
So, BPPV is benign paroxysmal positional vertigo. It is crystals inside the utricle of the ear get dislodged and come into the semicircular canals and they rest on hair cells, which gives the person the perception that they’re spinning. So, the world will start spinning around them and they’ll get vertigo. This is often when people are lying in a supine position when they’re on their back because it’ll activate the posterior canals and they’ll start to have that vertigo sensation.
There’s also horizontal canal BPPV when they’re laying on their side. Really it depends when you’re trying to get the person into the Dick’s Hall Pike – which is the position for looking at posterior canal BPPV – they have to have 45 degrees of rotation and 30 degrees or so of extension.
You can actually achieve this when we have their head off the table and they had to go into quite a bit of extension. But, you actually don’t need that. You can actually just do a little head tilt and achieve 30 degrees of extension.
The other option is if you have access to some sort of tilting table mechanism you can tilt the whole body up.
So, if they are that rigid and unable to achieve that level of extension – which is pretty minimal to be honest – but if you can’t do that find some way to try and maybe just tilt the whole body up so that their head and neck can remain in a neutral position. As long as you get that 45 degrees of rotation you should be able to access those posterior canals.
The other thing is that can be done easily is try to see if it’s a horizontal canal. Up to 85% of cases are going to be in posterior canal BPPV anyway, but about 10% are horizontal canal. This is the next most common. So, if it’s a horizontal canal, one way to test that is the BBQ roll or the supine roll technique.
In the videos that I have on my Instagram page (@concussion_doc), I show them supine and I turn their head 90 degrees or 45 degrees or so as much as I can get any way in terms of rotation directly to the side.
Elderly person might not have that much rotation, so what you can do to test it is just lay them on their side. Put a pillow under their head so that their head stays neutral. See if that evokes that down we’re beating nystagmus – what you’re looking for. Or, it could be upward beating depending if its apogeotropic or geotropic. That one you can test without having extension.
If that doesn’t work and you don’t elicit anything, try to see if you there’s any way you can get them into at least just a focal a little bit of extension. If that doesn’t work, try to see if you can get access to some sort of tilting mechanism to test them and to keep their whole body in a rigid plane.