We have discussed exercise on individuals with
relatively healthy brains and no history of cognitive impairment or disease.
But what about people who have already had
a stroke or even dementia or parkinson's disease.
Is it too late for them to benefit?
A six-month study looked at women diagnosed with mild cognitive impairment. After participating in a four times a week walking program, they were found to actually improve in their neuropsychological measures, looking executive function. Not only that, they had decreased levels of insulin, so better insulin sensitivity and reduced levels of cortisol which is involved in stress.
In the excel study which stands for exercise for cognition and everyday living, 86 women with objective cognitive deficits found on neuro-psychometric testing between the ages of 70 and 80 years were randomized to three groups. One doing aerobic training twice a week, one doing resistance training twice a week and the third group doing balanced training twice a week.
After just six months of training, subjects in the resistance training and aerobic training had significant improvement in their attention and decision-making compared to the balance training group.
How about cognition in parkinson's disease?
Parkinson's disease is a neurodegenerative disease that affects neurons that produce dopamine in the brain. It results in a slow and steady loss of motor and cognition functions. There are multiple studies showing the efficacy of exercise namely tai chi in parkinson's disease. Almost all studies favor tai chi. Tai chi was shown to improve the unified parkinson's disease rating scale, which measures motor function. It also showed that parkinson's patients having trouble with initiating movements had better scores and that their speed which is typically slowed because of the disease was much improved.
Nosera hitao showed that exercise not only improve the slow down of motor function, it also resulted in a less steep curve of cognitive decline. This has benefits on quality of life, decreasing falls from motor dysfunction, increasing independence in activities of daily living and slowing the progression of the dementia that can accompany parkinson's disease.
What do we know about stroke and exercise?
Most importantly, we know that exercise prevent stroke, exercise prevents or reverses high blood pressure and metabolic syndrome which is the combination of hypertension, diabetes, high cholesterol and obesity. It's not fully understood, but we do know that there is a dose-response relationship between physical activity and stroke, which has been proven in some analyses of the association between stroke and physical activity.
So, the more you exercise the lower your risk of stroke.
How about following a stroke? Where does exercise fit in there?
Of course strokes cause physical disabilities that can make exercise difficult and even sometimes unsafe. It must be monitored and guided by a professional like a physical or occupational therapist. A very well-studied physical therapy exercise called constraint induced movement therapy has been shown effective in rehabilitating arm dysfunction.
Their premise is that the good or unaffected arm is constrained often in a sling, so that the weak arm is forced to move and learn and get stronger. The specific therapy shows not only to increase arm strength which is achieved by other therapy modalities, but the strength also translates into independence in activities of daily living. A mental exercise important after a stroke is balance and mobility training.
Stroke can cause serious handicaps when it affects your legs or sense of balance. Exercise helps to recover that lost balance and return a sense of independence. Exercise after stroke also helps from a cognitive standpoint. One of the most debilitating post stroke deficits is actually cognitive decline which affects up to 65 percent of patients. Post stroke fatigue also affects 40 to 77 percent of patients. Exercise helps in both those domains.
Not only does exercise help with deficits caused by stroke, it helps increase quality of life and independence and it can also prevent another stroke. So, exercise is an important process that should be included in post stroke recovery.
In summary, fitness training has clear and positive effects on cognition for both normal aging adults and those with early varieties of dementia.