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Connectivity measures are robust biomarkers of cortical function and plasticity after stroke

Read Full Text: Connectivity measures are robust biomarkers of cortical function and plasticity after stroke (Free to access)
Journal: Brain
Year Published: 2015
Ranked 19th on our 2014-2019 list of the 50 most influential articles

Article overview for OTs

This is a very technical article, and that means it’s not an easy read—but it does provide some important glimpses into future trends, and it also gives us a baseline vocabulary for what to be watching for.

The study followed 12 patients over 28 days, during which time intense therapy was provided to patients in the chronic stage of stroke recovery. Therapy interventions targeted upper extremity motor deficits.

EEG (electroencephalography) was also used to measure the “functional connectivity” between the primary motor cortex and premotor cortex sections of each patient’s brain. Note that these sections were examined on the side of the brain with the stroke lesion.


(The above image is licensed through Creative Commons and gives you a good visual of the primary motor cortex and premotor cortex.)

The connectivity measures were then compared with improvement in the patients’ motor skills (as measured by the Fugyl-Meyer).

Ultimately, the study showed that there was a correlation between the “functional connectivity” measures and motor improvement!

The EEG readings were also shown to be predictors of gains from therapy.

Terms worth noting

EEG: An electroencephalogram (EEG) is a test that detects electrical activity in your brain. This activity is measured by using small metal discs (electrodes) attached to your scalp. (Source: Mayo Clinic.) Examples of EEGs currently on the market are listed below!

Biomarker (also called bio-marker): A measurable substance in an organism whose presence is indicative of some phenomenon such as disease, infection, or environmental exposure. From cancer treatment, to measuring chemical exposure, to rehab, biomarkers are somewhat of a holy grail, because they make things objectively measurable.

Brain structure versus brain function: In the simplest sense, imaging such as an MRI gives you a snapshot of brain structure (in this case, the damage done by a stroke). On the other hand, an EEG shows you how the brain is functioning. These two measures appear to be most helpful when they are used together.

How was OT involved in this article?

Not gonna lie, the usage of OT in this article is a little unsettling. And I don’t think we should turn a blind eye to this issue.

The UE therapy does not seem to have been delivered by a rehab professional. Instead, the article states that the therapy included “slide show diagrams” of OT and PT exercises, along with virtual reality computer games.

The article does say that the therapy delivery was adjusted according to individual deficits, but it does not say by whom, nor does it discuss the clinical reasoning used to determine how to adjust the delivery. It also does not mention therapy intervention specifics, such as doseage.

What is actually on the market

(This section is all of my own research, as particular devices were not mentioned in the article.)

We recently talked about how virtual reality systems were now on the market at 1/1000th of the cost that they were 20 years ago. EEG is on a similar trajectory as it becomes more and more affordable. The most well-known consumer-facing EEG device is the Muse Headband, which retails for $199.

That being said, the Muse only has four leads, whereas the EEGs used in this study had 256. From what I can tell an EEG with around 256 leads is still in the $25,000+ range, which is significantly less expensive than an MRI, but still not super affordable.

One would anticipate the cost of these devices to continue to decrease. And perhaps we’ll also see EEG devices that are designed for more specific purposes (perhaps even ones for specifically tracking healing from stroke).

Takeaways for OT

Start imagining the ability to measure who is a good candidate for stroke rehab, and if rehab is working.

This article indicates that the technology exists to objectively measure improvements in upper extremity motor rehab following stroke—and that these measurements can be gleaned by directly measuring functional brain activity. It seems like it is only a matter of time before this technology becomes more affordable and accessible.

As therapists, we need to start wrapping our minds around how technology like this might impact our practices.

Rapidly decreasing technology costs are going to make rehab tech devices available to consumers in ways we never thought possible.

While this study has a very specific focus, the implications of more affordable EEG systems (especially ones that can collect even more targeted brain activity measurements in the future) are far reaching.

Imagine as a school OT using EEG to track whether students are achieving an optimal learning state.

Imaging using something like Muse for our mental health patients.

And, for therapists who work with patients recovering from strokes, imagine taking this one step further and having EEG impact your therapy in real time. Brain-computer interface (BCI) devices are in their infancy, but expect to see brain computer interface rehab devices like this coming to the market.

The quest for biomarkers is emerging as a trend in OT-related research.

We all know that most of the assessments we use in rehab are insufficient for our needs. That is why, across the medical field, there is a push to find biomarkers that give us objective ways to measure the presence, and advancement, of specific diseases.

Something that this article really drove home for me is that not only could biomarkers help you concretely measure whether rehab is working—they could also give you an unprecedented baseline for understanding the likelihood that your rehab treatments will be effective in the first place.

Listen to a summary in podcast form:

Find other platforms for listening to the OT Potential Podcast here.

What questions/thoughts does this article raise for you?

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Holy buckets. @SarahLyon I can count on you to help me venture outside my OT comfort zone with these articles and this is certainly a case in point. This article topic blows my mind (no pun intended). It also caused an emotional reaction of defensiveness about OT AND a curiosity about how we’ve come to rely SO heavily on “objective” measures. Here’s the kicker, is this brain activity and being able to measure it REALLY important OR a possible distraction from the REAL power of OT? For example, isn’t the REAL measure of progress whether or not we are helping someone participate more fully? Do we really need fancy instruments to tell us this? I’m struggling a bit to digest all of this. What do you think the founders of OT would say about this research? I am tempted to think the fancy can distract us from the practical. For example, I will admit I struggle to see how majority of the clients I see in home health (who can barely afford a tub bench) would benefit from this level of research or device. AND I do ironically understand the immense value of research to purposely stretch our understanding and expand our dialogue. Definitely curious to hear more thoughts on all this from other readers.


I know! I laughed listening to my podcast summary because I used the phrase “I’m still trying to wrap my mind around this” so many times!

I agree with all of the points that you made, but would add this: whatever our response is to new technologies, we should not be caught off guard by them, but rather craft a thoughtful, intentional response.

Like, I said nothing has really hit the market that impact the average therapist, but it is worth starting to wrap our minds around it.

Also, we need more OTs like @lauren2 and @lauren1, who are working on the frontiers of rehab techonology and guiding how it is going to be used!

Very thought-provoking indeed! Thanks for challenging my brain, Sarah! As a pediatric OT, it makes me wonder if we could use EEG technology to show how sensory-motor activities such as swinging or cross-crawls impact brain activity?? And maybe eventually it would lead us toward the knowledge of which activities will be likely to help an individual child most based on which area of the brain we are hoping to target?? Wow - that would be super helpful information!!!


@gwen, your comment jogged my memory about seeing EEG used to detect “biomarkers of autism.”

The technology is still out of reach of the average practitioner, but what you mentioned definitely seems possible in our careers. I agree it would be super helpful to know what’s working and what isn’t!!

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I agree with you that though this article is very technical and does not really explain the functional aspect, we need to stay current and be aware of what is out there so as not to be caught off-guard (your words). Having said that, I am really curious about the n-Better machine which promises some good results as it can be used remotely (if and when cost permits). For OT to stay viable and prove its value (what a great profession) to others, we need objective methods such as the EEG machine/research to back it up. It would serve as a great biofeedback to our clients to SEE the neuroplasticity we talk about.


Hey @sanchala! I agree with you! And, I’m glad you brought up biofeedback, because I hadn’t mentioned that specifically. But, that is a huge part of the possibility here. A friend just told me about Recoverix, which is a device that combines EEG, VR, and electrical stimulation. To me, it is pretty mind-blowing the amount of biofeedback that patients receive with this device…not to mention the future possibility of technology like this!

A little off topic, but it’s interesting how we are seeing more and more studies including or looking at the effectiveness of virtual reality and therapy/programs delivered virtually. While I love technology and the opportunities it provides for the occupational therapy profession and clients/potential clients occupational therapy practitioners serve, I do not think anything can take the place of direct interaction with clients.


@megan1 Preach! I totally 10000% agree. @SarahLyon I can so appreciate your challenge to craft a conscious response to all this input about technology in the midst of wanting to pull my hair out sometimes. So much easier said than done AND challenge accepted:)

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I saw that Advent health pediatrics hospital for children in Orlando utilizes the recover x system.


I’ve been on such a huge learning curve this week! At the beginning of the week, I didn’t think technology like the Recoverix was on the market. But, after looking at the website, I’m realizing that there is one in CO, which is relatively close to me!

Sarah-Thankyou for this article review. It stimulated me to go deeper and understand better. Indeed it was not an easy read.
Having been in the profession for a long time I have been acutely aware of the ever increasing need for objective measurement to indicate progress following our Rxs. I know much work has been down to move forward toward that goal by clinicians, researchers, academicians and students. Thanks to all.
Interesting article and very promising and like Sarah said we should not be caught off guard. I totally agree with Megan that direct interaction is very important and satisfying to both patient and therapist. However, we still need to move onward keeping in mind current trends as dictated by our healthcare industry in terms of what is most cost effective. It has been my bone of contention and often times I have spoken to case managers and educated them. Sometimes I was successful and sometimes I was not. We have to go with the flow, continuously educating ourself and being positive in the best interests of our patients.
Also agree with Sanchala that we could very well use Biomarkers as a feed back strategy for the patients we treat so that they can actually ‘see’ neuroplasticity at work.
Enjoyed all the responses ! Thank you


Hi @sridevi, I love having your broad perspective on changing technologies and treatment opportunities! It is our human nature to want things to stay the same, but I love your go-with-the-flow attitude :slight_smile:

Totally agree from a clinical practice standpoint, its unlikely that devices like this will substantially change our practice - but, having better resolution to show changes in the brain as a result of treatment could be really valuable from a research perspective. Doing a study of occupation-based intervention compared to other things like exercise or medications would be really interesting and help build a case to see what the best interventions might be. It’s a good way to test our assumptions.

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Absolutely, @DevonCochrane, right now the implications are mostly for research, but it will be really interesting to see how affordable and accessible technology like this becomes in the next decade! Good thing you and I are sci-fi consumers so we are ready for things like this :slight_smile:

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