Dalfampridine and physical therapy: Effects on dual task performance for adults with multiple sclerosis

Dalfampridine and physical therapy:

Effects on dual task performance for adults with multiple sclerosis

A Capstone Project by Corinne Bohling, SPT

Background

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Multiple sclerosis (MS) is a chronic, progressive neurological disorder that is characterized by periods of inflammation in which demyelination of the nerve fibers occurs, resulting in lesions of the central nervous system (1).  The symptoms experienced by individuals with MS may vary greatly from person to person, but common symptoms include muscle weakness, fatigue, spasticity, and poor balance and coordination (2).  Importantly, people with MS are more likely to experience difficulty with maintaining gait speed when completing a cognitive task (referred to as “dual task cost” or DTC) than the general population (3).  DTC for people with MS has been linked to increased falls risk and has been suggested as an important target for intervention to decrease the risk of falling for this population (4).  DTC has also been associated with decreased gait speed during single-task conditions (5), suggesting that improvements in gait speed may improve gait speed during dual task activities.  Improved dual task performance via increased gait speed may then be useful in reducing the risk of falling for people with MS.

One pharmacological intervention has been approved by the FDA to increase walking speed for people with MS: dalfampridine extended release (D-ER) or Ampyra® (6).  D-ER is believed to affect gait speed by increasing nerve conduction velocity, and thirty-eight percent of people with MS who take D-ER experience at least a 20% increase in gait speed on a Timed 25-Foot Walk Test, which is a clinically important improvement (6).  This 38% of people are labelled “responders.”  The remaining 62% of people with MS who do not experience at least a 20% increase in gait speed when taking D-ER are labelled “non-responders”, indicating that non-responders do not experience a clinically important improvement in gait speed with D-ER (6).  Non-responders may then be less likely to experience improvements in DTC related to increased gait speed while taking D-ER. Currently, no published studies have investigated the potential effects of D-ER on DTC for people with MS.

Another potential approach to increasing gait speed for people with MS is physical therapy.  There is some evidence to suggest that physical therapy gait training interventions, including over-ground or treadmill training, can increase gait speed for people with MS (7-9).  This evidence is limited, however, due to a small number of studies and heterogeneity of the physical therapy protocols used in the studies.  Still, it has been suggested that gait training interventions aimed at improving gait speed may be effective at decreasing DTC for people with MS (5,10).

There is a growing body of literature examining the nature of DTC for people with MS, but little is known about the effects of D-ER, physical therapy, or a combination of the two on DTC for people with MS.  This information will be useful to health professionals and researchers looking for ways to improve safety and quality of life for people with MS.

 

Project Overview

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My capstone project involves a case study from the first participant in a pilot study with which two of my classmates and I assisted Dr. Prue Plummer over the 2015 fall semester.  To share our findings, we presented a poster at the Human Movement Science Symposium at UNC to share our case study.  We also worked together to compose a research article detailing our case study to submit for publication.  Through the poster presentation and article, we have shared and plan to publish information about the results and implications of our case study.  While our entire poster presentation and article describe multiple outcomes measured in the case study, my capstone project focused on dual task performance specifically.

 

Products

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In preparation for this capstone project, I completed a Critically Appraised Topic (CAT) to answer a question specific to the effects of gait training on dual task performance for people with MS.  While I greatly expanded my literature search beyond the articles included in my CAT to complete my capstone, my original CAT is provided below as an example and analysis of existing literature on the topic.

Critically Appraised Topic: Gait training and DTC

Ellese Nickles, Alexis Williams and I submitted the following abstract about our case study for acceptance to present at the Human Movement Science Symposium at UNC.

HMS Symposium Research Abstract

Our abstract was accepted for a poster presentation at the Human Movement Science Symposium.  We presented the following poster together at the symposium on February 26, 2016.

HMS Symposium Poster

We are currently working to complete final revisions on our manuscript to submit for publication to the International Journal of Multiple Sclerosis Care (IJMSC).  Due to the status of the manuscript, we are unable to publish our work at this time.

 

Evaluation

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We were able to distribute three evaluation forms to people who had discussed our poster presentation with us at the Human Movement Science Symposium.  The results of these evaluations are posted below.  Further evaluation of our work was received as successful acceptance of our abstract to present at the symposium.  We will continue to assess and learn from the feedback we receive as we look forward to the comments of our committee members and the outcome of our manuscript submission to the IJMSC.

Poster Presentation Evaluations

 

Reflection and Self-Assessment

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This project has really helped me to explore my interest in research while learning more in-depth about a topic and patient population that greatly interests me.  During my clinical rotations, I treated multiple patients with MS for whom dual task performance was negatively affected by MS, some of whom had been prescribed or were considering D-ER to help increase their gait speed.  When prioritizing goals for these patients, it would have been helpful to know what effects to expect from D-ER and how gait training with or without D-ER could affect dual tasking.  I asked a similar question about the effects of D-ER on outcomes other than gait speed at an information session I attended during the Consortium of Multiple Sclerosis Centers Annual Meeting in 2015, but company representatives for Ampyra® were unable to comment on other potential effects of the drug due to FDA regulations and the limitations of existing research.  By assisting with research, presenting a case study, and working on an article for publication about the effects of physical therapy and D-ER on dual task performance for people with MS, I feel that I have contributed to efforts that may help inform clinical decisions for physical therapists and other medical professionals who share my question in the future.  As I reflect back on this process, I find it very satisfying to be part of the development and dissemination of new knowledge!

While the end result and finished products are satisfying, the process was not without challenges.  I have learned that I function best with a routine and need to improve my skills at imposing structure on myself during independent work.  My greatest challenge was adhering to self-imposed deadlines at irregular intervals, and I am grateful to Dr. Plummer, Lexie, and Ellese for providing the external cues that I needed to stay on track.  The project also allowed me to experience the unknowns of a research environment first-hand, such as the unpredictable nature of scheduling participants to match a carefully orchestrated timeline, and the difficulty of addressing every potential intervention situation in a standardized protocol.  Working on this project, with its individual and group-work components, has also helped me to practice working in a collaborative environment.  Dr. Plummer, Ellese, and Lexie all introduced me to excellent strategies for helping to streamline communication and increase productivity throughout the project.

For future independent projects, I will know to ensure that I establish “check points” for myself at regular, frequent, and specific intervals so that my timelines become more predictable and routine.  For example, I might develop my list of deadlines similar to a course schedule, with defined components of the project due by 5:00 every Thursday.  I have also learned effective strategies to reduce confusion and support cooperative efforts during group project communication. This experience has helped me to gain skills and understanding that should serve me well as I approach my future as a PT.

 

Acknowledgments

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I would like to thank my partners in this project, Ellese and Lexie, for all of their contributions, positivity, and cooperation throughout the process.  Thanks also to our classmates, friends, and faculty who visited our poster presentation, challenged us to think on our feet, and provided us with encouragement and evaluations.  The contributions of Catherine Jacobs and Amy Thomas, who graciously accepted the responsibility of providing feedback for three third year DPT students simultaneously, are also greatly appreciated.

Thanks to our first research participant, who enthusiastically consented to be the subject of our case study to help advance care for people with MS.  I am grateful to have been a part of the MS STEP UP program over the past two years, which helped to shape and inform my interest in care for people with MS beyond what I knew existed, and to have worked with the Volunteer Leadership Team, who offered incredible support throughout the program.

Finally, heartfelt thanks go out to Dr. Prue Plummer, whose guidance and patience made this project possible for my classmates and myself.  Her insights and encouragement have fostered my love of research and sense of possibilities, the effects of which continue to unfold as I consider my career path beyond graduation.

 

References

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1. National Multiple Sclerosis Society. What is MS: Definition of MS. Natl Mult Sclerosis Soc Website. http://www.nationalmssociety.org/What-is-MS/Definition-of-MS. Accessed December 4, 2016.
2. National Multiple Sclerosis Society. Symptoms and Diagnosis: MS Symptoms. Natl Mult Sclerosis Soc Website. http://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms. Accessed December 4, 2016.
3. Hamilton F, Rochester L, Paul L, et al. Walking and talking: an investigation of cognitive-motor dual tasking in multiple sclerosis. Mult Scler 2009;15:1215-27.
4. Etemadi Y. Dual task cost of cognition is related to fall risk in patients with multiple sclerosis: A prospective study. Clin Rehabil. 2016 Mar 7. pii: 0269215516637201.
5. Sosnoff JJ, Socie MJ, Sandroff BM, et al. Mobility and cognitive correlates of dual task cost of walking in persons with multiple sclerosis. Diabil Rehabil. 2014;36(3):205-209.
6. Goodman AD, Brown TR, Schapiro R, T., et al. A pooled analysis of two phase 3 clinical trials of dalfampridine in patients with multiple sclerosis. International Journal of Multiple Sclerosis Care 2014;16:153-160
7. Hoang P, Schoene D, Gandevia S, Smith S, Lord SR. Effects of a home-based step training programme on balance, stepping, cognition and functional performance in people with multiple sclerosis – a randomized controlled trial. Mult Scler. 2016 Jan; 22(1):94-103.
8. Swinnen E, Beckwee D, Pinte D, Meeusen R, Baeyens J-P, Kerckhofs E. Treadmill training in multiple sclerosis: can body weight support or robot assistance provide added value? A systematic review. Mult Scler Int. 2012;2012:240274.
9. Vaney C, Gattlen B, Lugon-Moulin V, et al. Robotic-assisted step training (lokomat) not superior to equal intensity of over-ground rehabilitation in patients with multiple sclerosis. Neurorehabil Neural Repair. 2012;26(3):212-221.
10. Motl RW, Sosnoff JJ, Dlugonski D, Pilutti L a., Klaren R, Sandroff BM. Walking and cognition, but not symptoms, correlate with dual task cost of walking in multiple sclerosis. Gait Posture. 2014;39(3):870-874.

“Brain Juggling Ideas” image borrowed from: http://www.savagefuel.com/blog/ketogenic-best-productivity-diet/