Next up we had Ellen McGough present on Integrating Health Promotion into Physical Therapy Practice to Improve Brain Health in Aging Populations.
First Ellen graciously reminded us of 2 key definitions: Physical Activity is any body movement above rest that requires energy expenditure, while Exercise is a purposeful activity with a goal of physical fitness in mind. She then gently reminded us that increasing exercise is all well and good, but for the prevention of many chronic disease, advocating for increased physical activity will probably do the trick.
She then went into the risk factors for Alzheimer’s disease (which we discussed here as a form of dementia): non- modifiable risk factors of age and genetics; modifiable risk factors of diabetes, midlife hypertension, midlife obesity, physical inactivity, depression, smoking, low educational attainment. Funny how physical inactivity can play a role 4 of the other 5 modifiable risk factors. For every decade a person remains physically active, their chance of getting Alzheimer’s decreases by 10-20%. WOW!
Neurophysiologically, the brain begins to decline in the THIRD decade of life. It starts with cellular metabolism changes, which leads to alterations in neurotransmitters, cascading into cell death, then brain atrophy– first in specific areas of the medial temporal lobes and the hippocampus and eventually generalized brain volume loss. So how can we combat this? With physical activity at least and perhaps a little exercise! To see real results, one needs to participate in regular physical activity– aerobic and strengthening– for at least 6 months. Increased physical activity has been shown to increase brain volume in those specific areas that atrophy with Alzheimer’s. Besides that, completing as much general education as possible, but also specifically educating the public on this topic and not smoking. All of these things help increase the central reserve, which is the buffer zone of ability to maintain function despite neuropathology. This occurs by three mechanisms: neural compensation (adapting dormant connections), task dependent neural reserve (making new connections) and cognitive reserve (education). All of those things can come together to lengthen the “health span,” which is life in good cognitive and physical health.
We can also predict Alzheimer’s with biomarkers (in the cerebrospinal fluid (CSF), looking for tau protein tangles in biopsies) and imaging (PET scans to look at hippocampal volume, those tau amyloids in vivo, and glucose metabolism). Functionally in the clinic we might see decreased memory, executive decision making functions, participation in activities of daily living like shopping, dressing (ADL), mood changes, gait speed, stride length and increased stride length variability. Just before mild cognitive impairment (pre-clinical dementia), decreased gait speed, and balance, increased gait variability and falls show up. We see these people all the time. We really need to attack these populations with increased physical activity and warn them of the consequences: hastening the onset of dementia!