Dementia vs. Normal Aging: Key Differences Explained

Introduction

Old age comes with a number of complications, behavioral changes, and physical changes. At the same time, dementia presents several symptoms that are closely related to, or similar to, those displayed by people in old age. This makes it quite difficult for family members of an aging individual to determine whether the person is undergoing normal aging or has been affected by dementia. The difficulty is compounded by the fact that dementia is more frequent among older people than among younger ones. This paper examines both aspects and contrasts them, taking into account biological, psychological, physiological, and sociological perspectives.

Normal Aging: Physical and Physiological Changes

As we advance in years, the body gives way to several changes that were not present previously, and these changes occur at different rates for each person. The rate of aging and the onset of symptoms depend on genetics as well as the lifestyle an individual has lived or currently lives.

There are several symptoms expected to set in as an individual enters old age. There are physiological signs visible on inspection, such as less elastic skin, slower fingernail growth, and dry skin. The hair turns grey, and the person may develop scalp issues. There could also be a change in height — a loss of as much as 5 cm — through compression of joints and changes in posture. Hearing difficulties may develop, along with changes in the tone and fluency of speech. Most aging people will also develop presbyopia — the need for reading lenses — which typically sets in during the 40s and beyond. Reduced night vision may also occur, accompanied by a decline in visual sharpness and increased sensitivity to glare (Rawan T. & David M., 2012:2).

Changes in sleeping patterns are also common: the person will most likely sleep less deeply at night, and is prone to waking early in the morning or waking intermittently during the night.

Old age also brings natural bone loss, as bones become less dense and lose strength. During adulthood, people gradually lose minerals from their bones, leading to weaker bones in old age. This condition, known as osteoporosis, can be slowed by regular weight-bearing activities such as walking, by avoiding foods, drinks, and smoking that weaken bones, and by maintaining adequate intake of calcium and vitamin D.

There are also internal changes in body systems: metabolism slows, the heart becomes generally less efficient and circulation slows — particularly during heavy activity — and the lungs may become less effective, depriving the body of oxygen especially among inactive people. The kidneys decline in both size and function with age. Aging individuals may also experience urinary incontinence and a reduced sexual drive, particularly among women following menopause.

Neurological Changes in Normal Aging

Perhaps the most significant aspect of normal aging concerns the nervous system. From approximately the third decade of life, there is a general decrease in the weight of the brain as well as in the size of the neural network within it. This is occasioned by reduced blood flow within the brain. However, the brain adapts to these changes by developing new patterns in the nerve endings. Memory changes are considered a normal part of aging: people at this stage are expected to have reduced recall of very recent memories, and may be slower in remembering details and names than they were in younger years. Alistair B. & Michael Z. (2002:2) describe these changes as characteristic features of mild cognitive decline associated with normal aging rather than pathology.

Such loss of brain function can, however, be revived and revitalized through regular engagement in social activities, by challenging oneself to learn new things, and by remaining physically active — all of which help increase blood flow within the brain.

In old age, information processing generally slows, and older individuals may struggle to multitask. It is also quite common for older people to show considerable variability in cognitive functions. Notably, older individuals often surpass younger generations in their accumulated knowledge of the world.

Dementia and Alzheimer's Disease

While every person will experience some degree of memory loss as old age progresses, it is important to distinguish between normal memory loss and the problem of dementia or Alzheimer's disease among aging people.

Crucially, dementia is not normal aging. Dementia involves cognitive problems resulting from changes in brain function. It is understandable that many people conflate old age and dementia, since dementia is one of the most prevalent conditions seen in older adults. In a study conducted by Barry W. Roney et al. (2005), of the 454 older adults observed in nursing homes, 67.4% had dementia as their primary psychiatric condition.

There is general agreement that Alzheimer's disease is caused by the accumulation of a toxic protein known as apolipoprotein E (ApoE)-4 allele within the brain (National Institute of Health, 2012). Heijer T. et al. (2012) further indicate that people carrying this protein are commonly associated with lower hippocampal volumes, which is a predisposing factor for early signs of dementia and Alzheimer's disease. A study of 80 older persons found that over a period of 32.6 months, 27 of the 80 individuals who suffered mild cognitive impairment (MCI) due to hippocampal atrophy progressed to the Alzheimer's Disease type of dementia (Pieter J. Visser et al., 1999:478).

There is further indication that the condition can have an early onset — between the ages of 30 and 60 — but the most common form is late onset, appearing at age 60 and beyond (Sonia M. Rosso et al., 2003). Normal aging is not caused by this toxic protein and cannot have an early onset, which provides a clear distinction between the two.

Conclusion

Sadly, there is no known cure for dementia, and once it sets in at old age, there is a likelihood that the person will live with it until death, as noted by Guo S. (2012) in the International Journal of Alzheimer's Disease. The best approach is to remain aware of the condition through regular diagnosis, and to ensure that the individual receives appropriate care and support suited to their specific needs.

References

Barry W. Roney et al. (2005). The prevalence and management of dementia and other psychiatric disorders in nursing homes. International Psychogeriatrics — Cambridge Journals, Vol. 2, Issue 1.

Pieter J. Visser et al. (1999). Medial temporal lobe atrophy and memory dysfunction as predictors for dementia in subjects with mild cognitive impairment. J Neurol, Vol. 245, pp. 478.

Guo S. et al. (2012). Florbetaben PET in the early diagnosis of Alzheimer's disease: a discrete event simulation to explore its potential value and key data gaps. International Journal of Alzheimer's Disease, pp. 4.

Heijer T. et al. (2012). Vascular risk factors, apolipoprotein E, and hippocampal decline on magnetic resonance imaging over a 10-year follow-up. Alzheimer's & Dementia.

Kevin R. & Anna M. (2007). Dementia syndromes: evaluation and treatment. National Institute of Health: Expert Rev Neurother, Vol. 7, Issue 4, pp. 407–422.

National Institute of Health (2012). Alzheimer's disease genetics fact sheet. National Institutes of Health: National Institute on Aging.

Rawan T. & David M. (2012). The clinical problem of symptomatic Alzheimer disease and mild cognitive impairment. Cold Spring Harbor Laboratory Press, pp. 2.

Alistair B. & Michael Z. (2002). Mild cognitive impairment in older people. The Lancet, Vol. 360, pp. 2.

Sonia M. Rosso et al. (2003). Frontotemporal dementia in the Netherlands: patient characteristics and prevalence estimates from a population-based study. Oxford Journals: A Journal of Neurology, Vol. 126, Issue 9.

Toshioki M. et al. (2012). A warning index used in prescreening for Alzheimer's disease, based on self-reported cognitive deficits and vascular risk factors for dementia in elderly patients with type 2 diabetes. International Journal of Alzheimer's Disease, pp. 11.