Even though many believe that cognitive decline related to old age is inevitable, we should emphasise that an extensive research evidence shows that health and lifestyle strategies can defy and reduce the risks of many “age related” illnesses. Just because one is older, one’s life should not dwindle. Our gene-inherited tendencies may reveal our vulnerability towards certain diseases; however, it is the gene-environment interactions which determine our health pathways. Flexibility is easier to us than we think and with special treatment we can avoid rigidity and bad habits.

With that knowledge in mind, most people want to know how they can keep their brain sharp as they get older – what things should they do or avoid doing to keep their brain healthy.

Dementia diagnosis

There is a cluster of neurodegenerative diseases also known as “progressive diseases” (e.g., Alzheimer’s disease, Multiple Sclerosis, Parkinson’s, Motor Neuron Disease) and many of those are accompanied with what we call dementia. Dementia is a syndrome caused by brain disease and characterised by declining cognitive function that impairs: memory, language, attention, judgement, planning, behaviour, mood, and personality.

Most debilitating and widespread of these, especially among older population, is Alzheimer’s disease, with 1 in 12 Australians older than 65 now having it (Footnote: (ABS, 2021)). It is characterised by the presence of amyloid plaques and hyperphosphorylated tau in the brain (Footnote: (Swarbrick et al., 2019, Systematic Review of miRNA as Biomarkers in Alzheimer’s Disease)). Current diagnostic techniques for Alzheimer’s disease include cognitive assessment, neuroimaging and biomarkers detection, such as amyloid beta (Aβ) and tau protein detection in cerebrospinal fluid (CSF), blood testing (miRNA blood deregulation), retinal examination, breath, urine, saliva (infrequent method), and Transcranial Magnetic Stimulation (TMS) (Footnote: (Padovani et al., 2019, Transcranial magnetic stimulation and amyloid markers in mild cognitive impairment: impact on diagnostic confidence and diagnostic accuracy)). There are additional methods which tend to identify cell cycle, gene expression, or any other early sign that could help detect the disease onset. However, many of these procedures are costly and frequently done too late.

Some studies suggest that Mild Cognitive Impairment could be an early indicator of Alzheimer’s; while others suggest that its presence does not necessarily lead to development of Alzheimer’. Usually, a diagnosis of Mild Cognitive Impairment relies on extensive evaluation of cognitive and behavioural performances and refers to subjects with objective cognitive impairment with only minimal impairment in instrumental activities of daily living, who do not meet the criteria for dementia.

20 - 40% of people with Mild Cognitive Impairment have other dementia related disorders, such as Fronto-temporal dementia or Lewy bodies dementia, which affect individuals in their 30s, 40s and 50s, and these numbers are rising (Footnote: (Morrin et al., 2018, Systematic review of the efficacy of non-pharmacological interventions in people with Lewy body dementia)). Therefore, early detection of cognitive, emotional, and behavioural impairment is crucial for any dementia treatment. This is why many experts emphasise that to identify biomarkers may only be a first step, the cure is best achieved through prevention, because the diseases that cause dementia begin many years before any symptoms become apparent. The signs that Alzheimer’s is present may appear 20 to 30 years earlier (Footnote: (Swarbrick et al., 2019)). Disease gradually damages the brain until an individual can no longer function normally, thus, early intervention is our only hope in slowing its progression. Swarbrick et al. shows that miRNA blood deregulation is the earliest biomarker for Alzheimer’s disease to appear, some 20 years earlier.

Pharmaceutical treatments

Recent advances in dementia treatment, such as latest drug Aduhelm, were expected to deliver long-overdue relief and hope to many. Although approved by Food and Drug administration (FDA) in USA (Footnote: (June 2020)), it was done against the recommendation from the advisory panel. There was a pressure on FDA to produce the drug, the first one since 2003. The drug, costing $56,000, is supposed to remove amyloid plague during the early stages of dementia, but it is surrounded by controversy as only two studies submitted to FDA have contrasting conclusions. However, experts in memory and aging, such as Dr Scott Ayton (Footnote: (Head of the Translational Neurodegeneration laboratory at Melbourne, Australia’s Florey Institute of Neuroscience and Mental Health)), caution, while insurance companies in USA refuse to cover the drug. Doctors warn that Aduhelm is not a cure and question its proposed benefits, such as slowing down the disease progression. People are reluctant to use it and more clinical studies need to be done. On the other hand, what is not questionable is that it can cause cerebral haemorrhage, brain swelling and bleeding (ARIA), and brain volume loss in a significant number of patients (Footnote: (Mintun et al., 2021, Donanemab in early Alzheimer’s disease)).

Non-invasive brain stimulation

Other developments reported regarding dementia treatment and detection come from multiple non-invasive brain stimulation studies, such as Transcranial Magnetic Stimulation (TMS). Some of those have promising results (Footnote: (Neurophysiological biomarkers using transcranial magnetic stimulation in Alzheimer’s disease and mild cognitive impairment: A systematic review and meta-analysis Mimura et al., 2021; Transcranial magnetic stimulation predicts cognitive decline in patients with Alzheimer’s disease, Motta et al., 2017)). Motta et al. showed that TMS - based assessment of brain plasticity (LTP-like cortical plasticity) was a significant predictor of disease progression, when no other neurophysiological, neuropsychological and demographic parameters could predict cognitive decline. Following promising results, a range of ongoing trials and systematic reviews (Footnote: (Monash University, Melbourne, Australia -ongoing trial - A randomized controlled trial of Theta Burst Stimulation for the treatment of mild to moderate Alzheimer’s disease; Xu et al., 2019, The modulation effect of non-invasive brain stimulation on cognitive function in patients with mild cognitive impairment: a systematic review and meta-analysis of randomized controlled trials; Manitoba University, 2021, Investigating the Effect of Repetitive Transcranial Magnetic Stimulation (rTMS) as a Treatment for Alzheimer's Disease)) examines the effect of different non-invasive brain stimulation protocols in treatment of dementia disorders including Alzheimer’s disease.

Mimura et al. demonstrated that motor cortical excitability was increased, while cholinergic function was decreased in Alzheimer’s and patients with Mild Cognitive Impairment. Mankin and Fried (Footnote: (2020, Modulation of Human Memory by Deep Brain Stimulation of the Entorhinal-Hippocampal Circuitry)) suggest that due to vital involvement of hippocampus (its shrinkage is significant in dementia detection) deep brain stimulation of entorhinal-hippocampal system, the brain’s major memory hub, slows memory decline. These are all possible promising pathways.

Dementia and cognitive training

It is never too late to develop good brain health habits. Beneficial factors, such as mental and social involvement when integrated with physical activity can decrease the rate of cognitive decline in someone with dementia and improve their quality of life dramatically. Our brains are so plastic that even everyday same practices produce slightly different neural connections.

Cognitive training helps with many of cognitive problems, but for it to work it must induce neuroplasticity in brain regions and related networks that matter. No brain region should be seen in isolation. Enhancement in one region or network may result in inhibition of activity in another. Neuroplasticity refers to simulated activation of neurons and specific neuronal pathways, thus a familiar saying “Neurons that fire together wire together” means that when neurons fire together they strengthen their synaptic connections and are likely to fire in synchrony again, and due to repetition potentially build a new neuronal network.

Non-invasive brain stimulation studies (Footnote: (Nikolaidis et al., Parietal plasticity after training with a complex video game is associated with individual differences in improvements in an untrained working memory task, 2014)) have shown that cognitive training can transfer to a real-life activity. Furthermore, it is suggested that future cognitive training should be designed for maximum impact on brain activity, and for that a combination of cognitive training with physical activity to up-regulate biomarkers associated with neuroplasticity would be most effective.

Novel activity, such as learning new skills, has been associated with neuronal re-growth and neuroplasticity. Drawing is a simple, yet can be an intensely attention driven physical activity, which involves multiple brain regions and networks and is often implicated as beneficial in cognitive training (Footnote: (Fan et al., Relating Visual Production and Recognition of Objects in Human Visual Cortex, 2020)). Drawing from memory and life-drawing involve different processes, brain regions and networks. The task of drawing from memory evokes perceptual-motor encodings of visual images that preserve spatial information over short and long timescales. Therefore, perceptual-motor interactions directly serve as memory aids.

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