Exercise as it relates to Disease/Strategies to improve neuroplasticity in Parkinson's disease patients

This is a review of the article "The Effect of Exercise Training in Improving Motor Performance and Corticomotor Excitability in People With Early Parkinson’s Disease"[1].

What is the background to this research?

Parkinson's disease (PD) is a degeneration in an area of the brain called the basal ganglia, which is primarily responsible for the co-ordination of movement [1, 2, 3]. A patient suffering from Parkinson's disease can exhibit symptoms ranging from rigidity of the body, tremors and shaking when at rest, difficulties with walking, and other cognitive deficits. Traditionally, treatment has focused on maintaining a patient's strength, range of motion and identifying the particular impairments that a patient exhibits. The treatment exercise program is tailored to what the patient needs. For example, if a patient is exhibiting difficulty in taking big steps, the exercise program will incorporate an activity that will require the patient to take bigger steps. This works on the principles of neural plasticity, where the brain makes new pathways to allow us to learn new motor skills. However, there is little evidence in regards to the level of exercise intensity needed to receive the greatest impact from the neural plasticity [1, 2, 3]. This study aims to identify if exercising at a higher intensity will increase the growth and speed of neural plasticity, which will allow a patient to remain living an independent life for as long as possible.

Where is the research from?

Fisher, Wu, Salem, Song, Lin, Yip, Cen, Gordon, Jakowec, & Petzinger conducted this trial from the University of Southern California, in Los Angeles. It was published in the Archives of Physical Medicine & Rehabilitation journal, Volume 89, Issue 7, in July 2008. There was no conflict of interest mentioned.

What kind of research was this?

This study is a prospective cohort randomized controlled trial, staged in a clinical university setting looking at Parkinsons's disease patient's within 3 years of their original diagnosis, and with a Hoehn and Yahr diagnosis of stage 1 or 2.

What did the research involve?

Aim: The purpose of this research was to determine if higher levels of exercise intensity were associated with increased functional improvements in patient's with Parkinson's disease, when compared with patient's who exercised at a lower intensity. A secondary purpose was to determine whether functional improvements were positively correlated with an increase in cortico-motor excitability (neural plasticity) in the brain.

Methods: 1. Thirty patients with Parkinson's disease volunteered to be included in the study. All patients had to be relatively fit, and recently diagnosed with Parkinson's Disease. Patient's were not eligible if they were deemed to be unable to complete the exercises assigned.

2. To determine a baseline measurement, assessments were carried out looking at functional tasks including; sit to stand, walking, balance activities, and a measure of cortico-motor excitability of the brain via transcranial magnetic stimulation.

3. All participants were randomly assigned to one of three exercise groups; a high intensity, low intensity, and zero intensity exercise group as outlined below.

- High intensity group: consisted of 24 sessions of treadmill training where the participants had 10% of their body weight supported by a harness. Participants worked at 75% of their predicted maximal heart rate for around 45 minutes. This was for a period of eight weeks.

- Low intensity group: Consisted of 24 sessions of traditional physiotherapy exercises, focusing on improving range of motion, balance, walking, strength, and functional activities e.g. getting out of a chair. Participants worked at around 50% of their predicted maximal heart rate for 45 minutes. This was also for a period of eight weeks.

- Zero intensity group: Consisted of six lots of one hour education classes, over an eight week period. The classes were focused on quality of life, coping with stress, improving memory and cognition, and current treatment in Parkinson's disease.

4. After the eight week period had ended, all participants were re-assessed to determine if there was an improvement.

What were the basic results?

The results of the trial demonstrated an improvement from all three groups, however the high intensity group showed the greatest improvement, and the most consistent results. Further, when re-assessing the transcranial magnetic stimulation of the brain, all three groups showed an increase, however the largest increase was seen in the high intensity group[1].

What conclusions can we take from this research?

The conclusions that can be drawn from this study indicate that when utilising the principles of neural plasticity, it is important to work at a specific intensity to obtain the best results for your patient. Specifically, an individual with Parkinson's disease should work at an intensity of around 75% of their maximum heart rate for 45 minutes, three times a week, for at least a period of eight weeks to receive the greatest benefit[1]. Further, training should be task specific to receive even greater benefits[2]. Neural plasticity is thought to be improved when exercising at a higher intensity because it forces the participant to breathe harder, thereby causing an increase of blood and oxygen to the brain. It is theorised that high levels of oxygen and greater blood flow increases the rate of neural plasticity[3].

Practical advice

Some practical treatment strategies for a patient with Parkinson's disease would be education about the importance of high intensity exercise. They would need to understand that they shouldn't be able to talk and exercise at the same time. This is especially important in the early stages of Parkinson's disease as high intensity exercise will have the greatest impact, allowing them to remain active for longer[1, 2, 3].

Further information/resources

For additional information regarding Parkinson disease, please click the links below:


 * For general information about Parkinson's disease: http://www.parkinsons.org.au/what-is-parkinsons
 * For exercise in Parkinson's disease, scroll to "Exercise and Parkinsons disease": https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/parkinsons-disease
 * For information regarding medication in Parkinson's disease: http://www.parkinsonsnsw.org.au/about-parkinsons-disease/parkinsons-disease/treatment-and-therapies/
 * For information on services available in the ACT: http://health.act.gov.au/our-services/chronic-disease-management/chronic-disease-services/parkinsons-disease-service
 * For information about Parkinson's disease effect on cognition: http://www.pdf.org/en/cognitive_impairment_pd

References

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 * 1) Fisher BE, Wu AD, Salem GJ, Song J, Lin CH, Yip J, Cen S, Gordon J, Jakowec M, Petzinger G. The effect of exercise training in improving motor performance and corticomotor excitability in people with early Parkinson's disease. Archives of physical medicine and rehabilitation. 2008 Jul 31;89(7):1221-9.
 * 2) Tomlinson CL, Patel S, Meek C, Herd CP, Clarke CE, Stowe R, Shah L, Sackley CM, Deane KH, Wheatley K, Ives N. Physiotherapy versus placebo or no intervention in Parkinson's disease. The Cochrane Library. 2013 Jan 1.
 * 3) Petzinger GM, Fisher BE, McEwen S, Beeler JA, Walsh JP, Jakowec MW. Exercise-enhanced neuroplasticity targeting motor and cognitive circuitry in Parkinson's disease. The Lancet Neurology. 2013 Jul 31;12(7):716-26.