In Amplitude‘s November edition (coming your way any day now), we introduce you to a pair of VA researchers who are taking a novel approach to the study of phantom limb pain—and seeking volunteers to take part in their investigation. (See below to learn how you can participate.)
The researchers, Tonya Rich and Kierra Falbo, think PLP management has a hit-or-miss track record because PLP is inherently a hit-or-miss condition. Everybody experiences it in their own way, with a unique set of sensations, triggers, frequencies, and so forth. “Phantom limb pain can be really different for different people,” says Falbo, a former prosthetist who’s now pursuing a PhD in rehabilitation science at the University of Minnesota. “The experience can be really different, but also what seems to set it off, or what seems to perpetuate it can be different as well.”
That insight is guiding Falbo’s research with Rich, a PhD occupational therapist whose research is focused on practical, personalized interventions for patients with neurological injuries. Their joint study will pilot a new method for assessing patients’ PLP at the individual level, and molding the treatment to that person’s specific experience of PLP. “If we could figure out what factors contribute to phantom limb pain or perpetuate it in a person’s life,” Falbo explains, “we could theoretically target those factors in a treatment tailored to that individual.”
Amplitude only had limited space in our print edition to describe this project, so we’re offering some additional details here in Q+A format. Falbo and Rich are actively seeking research subjects, and the study is open both to veterans and non-veterans. If you’re interested in participating, contact Falbo at firstname.lastname@example.org. Our conversation is edited for length and clarity.
You’re going to be studying phantom limb pain through the lens of “ecological momentary assessment.” What’s unique about EMA?
FALBO: Ecological momentary assessment involves repeated surveys, a couple times a day, over a couple of weeks. That allows you to gather a lot of data on one individual person at various times, both when they are in pain and when they’re not in pain. When you analyze the data, you can look at patterns that might help you understand what they are doing that might lead to pain. Maybe lack of sleep tends to lead to their pain, or maybe stress tends to lead to their pain.
RICH: One of the things we’re trying to change is to have better measurement so we can stop just throwing things at the patient. People with PLP have been told for years: “Try this. Did it work? Nope? OK, then try that. Nope, that didn’t work either. . . .” I mean, what kind of sales job is that for an intervention? How defeating to be told, “If you want to try this intervention, here you go,” without knowing if it actually applies to you as an individual. We’re trying to open the conversation up and pinpoint what personal and environmental factors are actually contributing [to PLP] for each individual.
And how do participants know when to record their data? Will they get smartphone prompts at random times throughout the day?
FALBO: We’re planning to do it at set times, based on that person’s daily schedule. So they’ll do a morning survey when they get up in the morning, and evening survey before they go to bed. As you said, they’ll get a prompt on their phone.
One of the big benefits to EMA is that you get the data in real time. They’re filling out the survey as soon as they get the prompt; they’re not trying to think back to what their pain was like last week, or how much sleep they got last week. Everything’s fresh in their minds, so hopefully you get more accurate data. They’re also giving data as they going about their day-to-day life in their home, or whenever they’re active outside their home. So that’s the “ecological” part. It’s measuring their pain in relation to daily activities.
And what will participants be queried on? It sounds like pain level, obviously, is one factor. You mentioned sleep as another one. What are some of the other things you’ll be gathering data on?
FALBO: Our first step is to figure out what questions to ask. Because there’s a lot we don’t know about phantom limb pain. There are a lot of things that could be associated. We’ve reviewed the literature to look at what’s been published so far, as far as evidence for factors that might be associated. But we also plan to hold focus groups with individuals who’ve experienced PLP to asking them what factors they think are associated. When I worked as a prosthetist, seeing patients every day, they would often tell me, “I’ve realized that I tend to get phantom limb pain when I do this, or when XYZ happens.” A lot of people have an idea of what might might cause it or or contribute to it, so we want to get their input as well.
We’ll take what we hear in the focus groups and what we’ve gotten from the literature, and we’ll compile a list of of questions. The other factor is that we’re really looking for things that we might be able to target in a treatment. We want to gather data about things that are modifiable, that we could do something about.
And when you say “modifiable,” I gather than you’re looking for behaviors or activities that could be treated through OT, PT, or some other type of rehab treatment?
RICH: I’m an occupational therapist by background, and when I worked in clinical practice I became very interested in pairing interventions in the nervous system with rehab to get better outcomes. I did my PhD research on non-invasive [i.e., external] brain stimulation paired with motor training to improve motor control in children who’d experienced stroke. So the possibility is whether the same paradigm could work with PLP. If we knew how an individual is wired, and we could give them some stimulation and pair it with high-quality rehab, who knows what the possibilities are? The goal is to develop and test interventions that can be done in the home on a day-to-day basis, rather than something where patients need to visit a clinic for weeks on end.
What might some of those interventions look like? A simple thing might be, “If I get eight hours of sleep, I experience less PLP.” Maybe it’s premature to ask, but I’m just curious what other types of treatments might come out of this.
RICH: Those are all things that remain to be seen. The first big step is to see whether we can identify, for an individual person, what the biggest contributing factors are to their PLP. The next big step will be: If jwe intervene on those contributing factors, does that actually reduce their pain? Does it actually have an effect? And then if that works, the next question will be: How do we implement this into a clinic? How do we get clinicians involved? How would this fit into everyday care?
Does “getting clinicians involved” refer only to prosthetists? Or are there other clinicians who would be part of the intervention?
FALBO: I think it depends. We’ll be looking at how anxiety and depression affect PLP, so that would typically fall under a mental-health clinician. We’ve got survey questions around pain catastrophizing, which could be addressed with pain education, and that could come from a PT, an OT, or potentially a prosthetist. There might be some people where physical activity could improve their phantom limb pain, and that might come from a PT. This research is very multidisciplinary, and that’s the only way to go in healthcare, in my book.
RICH: There’s been a real reframe in pain rehabilitation. Our primary goal is not to get your pain intensity down. We’re working to get pain interference down, so pain interferes with daily life less and you’re able to function more. Over time, hopefully your pain intensity will also come down. But the immediate goal isn’t to get your pain intensity down from nine to six. It’s really about getting people back to where they can function. The more I’m in this domain, the more I think it’s going to take individualized approaches to be successful.
How can people volunteer for your study?
FALBO: The first thing we’re recruiting for is the focus groups to help us develop the EMA surveys. The actual EMA portion, the data gathering, will likely begin next summer. But if you’re in the focus group, you can also participate in the EMA portion. It’s not one or the other. If people are interested in the EMA portion [rather than the focus group], they can get in touch with us now and we’ll keep them on a list to contact later on.
If you’re interested in participating in the EMA study, contact Falbo at email@example.com. To learn more about Rich and Falbo’s PLP research, see “Veteran Perspectives on Phantom Limb Pain and Non-Drug Interventions” in the Journal of Pain Research.