Exercise as it relates to Disease/Aerobic training's effect on cognitive performance in elderly individuals with dementia

This wikibook article is a critical appraisal of the journal article “Effect of aerobic training on the cognitive performance of elderly patients with senile dementia of the Alzheimer type”.

What is the background to this research?
Dementia of the Alzheimer type increases with age, effecting the occupational and social skills of older individuals. It is a result of the deterioration of brain tissue, effecting the hippocampal part of the brain and the function of cortical and sub cortical regions of the brain, causing cognitive impairment. Evidence suggests that aerobic exercise can be used as a possible intervention to protect against dementia pathologies and preserve brain function by increasing cerebral blood flow.

Due to excessive sedentary behaviour in the elderly community the prevalence of dementia has increased and is estimated to effect 369,977 Australians.

The study was designed to examine how a 3-month exercise intervention plan would affect the neuropsychological performance of cognitive tasks in clinically diagnosed patients with senile dementia of the Alzheimer type.

Where is the research from?
The research was conducted at the Sapienza University of Rome in Italy by Palleschi, Vetta, De Gennaro, Idone, Sottosanti, Gianni and Marigliano. The study was published by the Archives of Gerontology and Geriatrics, which is an international journal that facilitates articles by specialists in the fields of gerontology and geriatrics. The journal is ranked 28th overall in journals of the same field Although the study was published in Rome it is still relevant to Australia.

Palleschi has focused on animal-related studies since the study was published in 1996, while Vetta has continued to undergo studies in the field of elderly health.

What kind of research was this?
The research would be categorised as an observational study as there was no variance in the intervention between subjects. It followed the cohort study procedures as it followed the same group of individuals who were assessed for the entire 3-month duration of the study. Due to the studies objective a cohort study would be an acceptable practice.

What did the research involve?
The study included 15 subjects, all male, average age being 75 and all were clinically diagnosed with SDAT. Studies took place over a 3-month period after a 3-week period of no pharmacological products that could potentially interfere with the results of the study.

The methodology as follows:
 * Patients were assessed prior to beginning of the intervention as the baseline studies included attentional matrix, verbal span test, supraverbal span test and mini mental state examination.
 * Subject underwent a training program 3 days a week, cycling on at ergometer at 70% of their maximum pulse rate with sessions lasting up to 20 minutes.
 * Exercise intervention continued for 3 weeks; at the end all baseline assessments were re-assessed to analyse.

No further interventions took place.

What were the basic results?
The results for the follow up assessment after 3 weeks of adherence to the program showed improvement in all categories of the psychometric tests, with results consistently improving among the 15 subjects.

Test improvements included:
 * Attentional matrix: +7.97
 * Verbal span test: +0.98
 * Supraverbal span test: +5.62
 * MMSE: +2.33

Although there were improvements across each stage of the study, there are still a lot of variables regarding adherence to program of this design that have gone undiscussed. Older individuals might find the program too difficult, especially as they progressively get older. The patient’s motivation is also a factor due to the monotonous aspect of the intervention and apathy effecting 50% - 70% of dementia patients. The study also doesn’t take into account disabled and handicapped dementia sufferers who would physically be unable to use a cycle ergometer.

What conclusions can we take from this research?
The research has proven that aerobic training as an intervention used in an elderly population suffering from senile dementia of the Alzheimer type can be an effective way to slow the deterioration of progressive dementia in a short term. More studies should be done before implemented into a population, testing on a larger cohort and mixing the studies so females are involved as well. The limitations of this study are that it didn’t take into account larger variables like long term memory or cortical atrophy. The study also didn’t examine the mental health and well-being of the patients, while other studies used more measures like depression, prior health conditions and lifestyle characteristics. Considering its release in 1996, a lot of the methods would be considered outdated to today’s standard.

Basing their evidence on these 4 tests alone in a 3-week time period is not sufficient evidence to claim that aerobic exercise can improve dementia in the long term. Due to the brevity of the study, further research is required to fully understand the effects of aerobic exercise on dementia.

Practical advice
To build on the methodology of the study in the assessment stage, before and after the intervention, the researchers should include wider baseline of measurements. A physical function assessment should be performed to gauge the capabilities of the participants of the study and prescribe exercise according to their capabilities. An alternative to the cycle ergometer could be aerobic swimming classes as it alleviates stress on muscles and joints. Depression could be measure by using the centre for epidemiological studies depression developed in 1977. It is also advised that the ADAS cognitive behaviour form is used to measure the severity of the dementia and participants are provided with support and motivation from researchers.

Further information/resources
https://www.dementia.org.au/files/helpsheets/Helpsheet-DementiaQandA08-PhysicalExercise_english.pdf

https://www.aihw.gov.au/reports-data/health-conditions-disability-deaths/dementia/overview

https://www.caregiver.org/caregivers-guide-understanding-dementia-behaviors

https://www.dementia.org.au/support/services-and-programs/services-and-programs/support-groups