Not Everyone With Mild Cognitive Impairment Progresses To Dementia

Last Sunday(05/29/11) almost two columns of Letters to the Editor appeared in the Opinion section of The New York Times. Most were written by family members objecting to a piece written by Brandeis scholar Margaret Morganroth Gullette. In her article she challenged the prevailing theory that most people who are diagnosed with mild cognitive impairment (MCI) will progress to dementia. Unlike elders with normal varieties of mental decline who usually avoid Alzheimer's disease, the diagnosis of MCI predicts serious intellectual deterioration within a few years.

Ms. Gullette pointed out that many people with mild impairment learn to compensate for their cognitive losses. With a positive attitude and the support of loved ones they do not develop dementia. As might be anticipated, those with loved ones who suffered the ravages of Alzheimer's disease and other forms of dementia objected to the portrait of elders with MCI living happy, fulfilling lives. Their experience has been just the opposite: a proud, charming, and beautiful grandmother declining into Alzheimer's disease and becoming crazed, violent and mute; a man beloved for his kindness and humor deteriorating into an agitated, angry, and fearful person with no connection to the world around him.

Professionals weighed in. Neurologists who have watched their patients with MCI struggle to continue to function independently, worried that pointing out that not everyone with this diagnosis develops severe impairment minimizes the daily challenges that they face to lead a normal life.

My own reaction to this heated discussion is that we need to learn more about the characteristics those seniors with MCI who do not progress to dementia. In my own research I looked closely at studies on three continents that followed people with MCI for 3-5 years. At follow-up the investigators classified the patients as having progressed to dementia; stable; or no longer impaired. On average the investigators found that nearly half of the individuals did not progress to dementia as anticipated. Even more surprising was that one in seven were no longer impaired.

A great deal of research has been published about the psychosocial characteristics of those more likely to progress to dementia. But no systematic study has identified those behaviors or lifestyle habits that distinguish those MCI patients who do not progress to dementia, who remain stable or who revert to normal cognitive aging. What an important research project this would be.

25 years ago 26% of US citizens 65+ were disabled. The most recent surveys put the number at about 19%. In an effort to understand the reasons for this declining disability, a great deal of research has been carried out. Two factors that contributed are advances in medical technology and healthier lifestyle habits practiced by older adults.

There is no shortage of testable theories to explain why some of those with MCI do not decline further. For example, we might speculate that some of these newly diagnosed MCI patients take matters into their own hands and begin to practice healthy lifestyle habits such as exercising and eating healthily, which enhance the mind along with the body, retarding the progression to dementia. Another hypothesis is that some people diagnosed with MCI seek and receive successful treatment on their own that halt cognitive decline and/or restored something approximating normal intellectual functions. Though medications and cognitive training have not been widely successful with MCI patients, some people have been helped.

I find myself wondering whether anyone reading this blog might be acquainted with individuals diagnosed with MCI who have has stabilized or have returned to normal cognitive aging. If you know of anyone I would enjoy hearing from you.

Selected References

Ravaglia, G ., Forti, P ., Montesi, F ., Lucicesare, A ., Pisacane, N ., Rietti, E ., et al . (2008) . Mild cognitive impairment: Epidemiology and dementia risk in a large elderly Italian population . Journal of the American Geriatrics Society, 56, 51-58.

Lopez, O . L ., Kuller, L . H ., Becker, J . T ., Dulberg, C ., Sweet, R . A ., Gach, H . M ., et al . (2007) . Incidence of dementia in mild cognitive impairment in the Cardiovascular Health Study Cognition Study . Archives of Neurology, 64, 416- 420.

Tschanz, J . T ., Welsh-Bohmer, K . A ., Lyketsos, C . G ., Corcoran, C ., Green, R . C ., Hayden, K., et al ., & the Cache County Investigators . (2006) . Conversion to dementia from mild cognitive disorder: The Cache County Study. Neurology, 25, 229-234.

Huang, J ., Meyer, J . S ., Zhang, Z ., Wei, J ., Hong, X ., Wang, J ., et al . (2005) . Progression of mild cognitive impairment to Alzheimer's or vascular dementia versus normative aging among elderly Chinese . Current Alzheimer Research, 2, 571-578.