Evidence of meeting #115 for Veterans Affairs in the 42nd Parliament, 1st session. (The original version is on Parliament’s site, as are the minutes.) The winning word was symptoms.
A recording is available from Parliament.
Liberal
Darrell Samson Liberal Sackville—Preston—Chezzetcook, NS
Is there an area we should focus on and research? Is there a recommendation that you would make?
Optometrist, As an Individual
Yes, there are particular symptoms and signs that have shown up in the patients we see. A lot of it has to do with coordinating with the vestibular system. For instance, the patients we see with mefloquine toxicity that I'm aware of tend to have what we call vertical phorias, or the two eyes want to be pointed a little bit up and down instead of on the same plane. That makes horizontal surfaces ambiguous to your brain, because your two eyes are not giving you the same information. Those vertical phorias in brain stem injury tend to change when you look from left to right, so you get different information about horizontal surfaces as you move your eyes. Vertical phorias seem to be an issue. The convergence insufficiency, where you are having trouble pulling your eyes inward as is necessary for reading, tends to be an issue. It's also a brain stem-related function.
Then, of course, there's coordinating the vestibular system—for instance, one of my patients had difficulty moving his eyes. When he moved his eyes from looking far to looking near, he would go into a tumbling vertigo, so we were trying to figure that out. It turned out that he had both the vestibular neuropathy and a vertical phoria that changed from distance to near, such that one eye was up at distance and the other eye was up at near. There was no opportunity for his visual system to stabilize the vestibular system.
Liberal
Darrell Samson Liberal Sackville—Preston—Chezzetcook, NS
Thank you.
Dr. Douglas, it is nice to see you again. I think we all agree around the table that tracking is probably the most challenging thing we need to be doing more of, so that we have the facts and we can draw on those facts and then find solutions to the issues on the table. I think we can put systems together to track; there is no question about that.
When the other countries like Australia and...?
Liberal
Darrell Samson Liberal Sackville—Preston—Chezzetcook, NS
Yes, it's the U.K. They have done some research and they are saying that there are some links, but I don't get the direct link. They are saying that there are possibilities but it's not directly PTSD. Can you expand on that? When I look at those studies it's not as clear as night and day that it's directly an effect.
Psychologist, Central Ontario Psychology, As an Individual
Yes. As I say, unfortunately, I'm really not an expert. I would direct that question to Dr. Nevin. I think he might be much more familiar with it than I would be, but it is my understanding that essentially what it boils down to is this: Those who are exposed to mefloquine and have had that prodromal reaction to mefloquine are substantially more likely to be diagnosed with a psychiatric disability.
Liberal
Darrell Samson Liberal Sackville—Preston—Chezzetcook, NS
But we don't know what numbers that is based on because we're not doing the tracking.
Psychologist, Central Ontario Psychology, As an Individual
In Canada we're not doing the tracking, no.
Liberal
Liberal
Conservative
Robert Gordon Kitchen Conservative Souris—Moose Mountain, SK
Thank you both for being here today. I've learned something new because I was not aware of neuro-optometry, so I appreciate that.
I could spend hours talking with you, Dr. Suter, about many things, but I'm limited on time so I will try to be as quick as I can.
We talked about quinolones, basically, dealing with their having caused brain stem injuries. We know that there are 12 cranial nerves and basically 10 of them come from the brain stem and two of them don't. As for the oculomotor nerve—and I'm assuming that's where the interaction between vision, which you've been looking at, and the oculomotor disturbances is—I'm wondering if you could expand a bit more on that for us.
Optometrist, As an Individual
In those cranial nerves that are coming off the brain stem, the information is kind of flowing from the bottom. The eighth cranial nerve is your vestibular nucleus. Then the information comes up to the sixth, the fourth and the third, all of which involve coordinating your eye muscles. The vestibular system tells us where our head is going so that the information then moves up the brain stem so that we can coordinate head and eye movements and keep our fixation stable, even though our head is moving. I think that is a huge part of what is happening here, that you're ending up with interruptions in that pathway.
Conservative
Robert Gordon Kitchen Conservative Souris—Moose Mountain, SK
When you're seeing patients who have been on mefloquine, how are you testing it? What are you looking for when you do this with that specific patient?
Optometrist, As an Individual
With any brain injury patient, we are looking very carefully at eye alignment. With the traditional eye exam. you don't really look at eye alignment very carefully. If they're not complaining of double vision, then you don't test out the fine details.
There are techniques whereby you separate the vision from the two eyes. You have one eye seeing a line and one eye seeing a line and you just say, “Tell me when it lines up.” You can measure very accurately what the misalignment is in all kinds of different fields of gaze. We usually measure nine fields of gaze, because it changes in nine fields of gaze.
There are, then, instruments that are simple and easy to use, which any practitioner can use. This might be something that would be good to make standard for your optometrists or your vision specialists who are testing veterans.
Conservative
Robert Gordon Kitchen Conservative Souris—Moose Mountain, SK
Okay, thank you.
I think we've all heard and you both have indicated that the reality is that we need to make certain we're doing the proper diagnosis, whether it's of PTSD or of mefloquine toxicity. That's ultimately what we're looking at—what diagnoses we need. Obviously we need more research along those lines.
On that note—and Dr. Douglas, you touched a little bit on this when you pointed out to us the criteria—when we're looking at the criteria, and particularly when you talked about someone being exposed to an event, if you were exposed to that event and you had other factors on top of it, what would be the potential that we could see a greater reaction, greater responses?
Psychologist, Central Ontario Psychology, As an Individual
I think the potential is certainly there, absolutely. For example, PTSD tends to be cumulative, so if you have more and more exposures to trauma, you can absorb so many and then you'll get the one that breaks the camel's back. Obviously there are multiple factors. Life at home can add more stress and then make PTSD more likely and lead to a stronger reaction. As I said, I think something like mefloquine could very well make it more likely that someone's going to have a traumatic reaction to a given event.
Conservative
Robert Gordon Kitchen Conservative Souris—Moose Mountain, SK
Are you aware of any specific medications that might react with mefloquine?
Psychologist, Central Ontario Psychology, As an Individual
I'm not aware. That would be outside of my purview, for sure.
Conservative
Psychologist, Central Ontario Psychology, As an Individual
That could also be an issue, but again, I'm not the right person for that question.
Conservative
Robert Gordon Kitchen Conservative Souris—Moose Mountain, SK
But those would be things worthwhile researching, isn't that correct?
Psychologist, Central Ontario Psychology, As an Individual
Absolutely, yes.
Conservative
Robert Gordon Kitchen Conservative Souris—Moose Mountain, SK
Definitely we would want to know this. I see it when I travel overseas. We see it not only in our military population, but in the civilian population who travel overseas. Often our doctors are prescribing the first thing that comes along, and it's mefloquine.
In fact, when I went to Pakistan, that was the first medication my physician offered me. Knowing what I know, I chose doxycycline, but the reality is that not everybody knows that information. It has a big impact for them. We hear of civilians travelling in Asia, especially the Australians, who say.... When my son was overseas in Thailand, and he said he was taking it, they told him to get off it, because they're aware of it but Canadians aren't.
