From the simplest cells to complex creatures gifted with language, imagination and creativity, life has a beginning, interims and an ending.

There’s no escape: good genes, a healthy lifestyle, timely, effective intervention and treatment along the way, and luck, may put off this or that threat, but in the end, there is an end.

The fact that there is an end, however, is out of sight and mind for most people most of the time, except for illnesses and deaths  affecting family and friends.

Life between birth and the early thirties is spent learning and honing increasingly elaborate sensori-motor skills, learning languages, how to read the intentions and feelings of others, developing a sense of self-awareness, fitting in with increasingly large and complex social communities, and adopting family, cultural and community ideas and norms.

Then come the middle years between the early thirties to the late sixties.

This four-decade period is, for the most part, a period of consolation and continued learning from experience and, like the earlier period, a time most take good health for granted and adapt to new challenges in the work place and home with relative ease — most times.

Even so, there are warning signs: MRI studies suggest that during this middle period, the neocortex begins to shrink, even if there are few if any obvious functional correlates.

Physiological studies by Alan McComas at McMaster University suggest the sixth decade marks the beginning of losses of motor nerve cells in the spinal cord.

If so, there are probably similar losses, affecting other nerve cells in the brain and spinal cord, even though studying other nerve cells is harder to do compared to the relative ease with which motor nerve cells can be studied.

Nerve cells losses are accompanied by losses of the connections those cells had with other nerve cells and, in the case of motor nerve cells in the brainstem and spinal cord, with muscle fibers.

Despite these losses, the impact on function many be minor initially because surviving related nerve cells manage to cover the functional deficit, until they too begin to succumb.  

What sets the eighties apart from the seventies is that degenerative changes and the accumulation of misfolded proteins such as beta amyloid and tau become increasingly common, and clinically significant cognitive and memory changes eventually affect one-third or more of those in their eighties.

The eighties are marked also by the cumulative impact of other challenges such as the increasing prevalence of deafness, macular degeneration and significant degenerative disease in the lower back, hips and knee joints that, coupled with cognitive and memory losses, lead to significant functional disabilities and limit mobility, balance and social activities.

By this time in life, atrophy of the brain is very obvious and marks the loss of large numbers of nerve and other supporting cells in the brain.

The impact of cognitive changes on social activity is very apparent among those with dementia in long-term care facilities.

My observation is that residents with dementia rarely form meaningful relationships with other like-affected residents despite living together in community for many months and even several years.

With social isolation comes a withering of social and language skills, which compound the problems associated with isolation.

That’s where well-trained and motivated staff can make a big difference by making efforts to talk to individual patients and listen to their responses.

Residents do respond to cheery, literally hands-on staff, but not so much to planed group activities.

While it may be useful for clinical purposes to separate the cognitively healthy from those with early signs of dementia, the fact that the percentage of those with dementia continues to rise in the nineties suggests that the spectrum is seamless and that eventually, the majority of those in their nineties will suffer from significant cognitive impairment made worse by social isolation as friends of similar age become affected or die and social worlds contract.

Despite the claims of pharmaceutical companies championing drugs that clean up beta amyloid and even tau, I doubt there will be a truly effective safe drug for Alzheimer’s disease anytime soon.

Given the burgeoning numbers of cases of dementia, it’s very important that the province plan for far more and better care for seniors, much as some western European countries pioneered for humane care for elders.

That will mean huge investments and higher training standards and salaries for those who provide the care for those out of sight and mind for most Canadians.

Dr. William Brown is a professor of neurology at McMaster University and co-founder of the InfoHealth series at the Niagara-on-the-Lake Public Library.