“Oops, I Think I Did It Again:” Yet Another Misdiagnosis of Alzheimer’s Disease

The words instill dread in the hearts of the American public.

While cancer remains top vote-getter in the frightening arena, with 41% of respondents to a 2011 survey for the MetLife Foundation in 2011 conferring upon it ‘most-feared’ status [see “The Winner on Fear-Factor: Cancer“], Alzheimer’s clocks in at a close second, with 31% of the votes. [Note that the next two diseases are stroke and heart disease, each at 8% of respondents, a 23-point differential.]

The picture painted by the Alzheimer’s Association of the omnipresence of Alzheimer’s Disease (AD) in society feels like one of doom and gloom. Their Quick Facts section informs us that, as of 2012:

• 5.4 million  Americans, or 1 in 8 older Americans, have Alzheimer’s.
• Alzheimer’s is the only cause of death among the top 10 in the United States that cannot be prevented, cured or even slowed. {“Based on final mortality data from 2000-2008, death rates have declined for most major diseases—heart disease (-13 percent), breast cancer (-3 percent), prostate cancer (-8 percent), stroke (-20 percent) and HIV/AIDS (-29)—while deaths from Alzheimer’s disease have risen 66 percent during the same period.“}

With organizations like the Alzheimer’s Association working hard to get out the word on the prevalence and destructiveness of the disease, and with more Americans aging and coming in contact with those who have the illness, the levels of fright and near-panic surrounding it have increased in recent years, and, since AD has no known cure, and a long course of decline, people feel hopeless in the face of its path.

AD has taken hold of the American psyche, filling it with anxiety.

But what if, just what if, these highly advertised statistics were wrong–and Alzheimer’s is less common–perhaps as much as 50% less common–than is now believed? That wouldn’t nullify the worst aspects of the disease, but it would require a second look at our beliefs about its prevalence, which might very well soothe some of our fears.

I ask. . .because that just might be happening.

Researchers working on the Honolulu-Asia Aging Study (HAAS), ongoing since 1991, have been studying the brain changes caused by Alzheimer’s and other forms of dementia, and have a fairly clear grasp–post-mortem, that is–of what is Alzheimer’s–and what is something else completely.

They autopsied the brains of 211 men diagnosed who had been diagnosed with dementia during their lifetimes, and the dementia was most frequently attributed to the decline of Alzheimer’s.

But. . . . the autopsies revealed that about half of those diagnosed with Alzheimer’s lacked the appropriate number of lesions to reflect the ravages of the disease.

The rest had other brain abnormalities that might explain dementia–but were not consistent with Alzheimer’s.

Said Lon White, a professor of geriatric medicine at the University of Hawaii, and director of the HAAS,

There are at least five different kinds of important lesions which can produce a picture that looks like Alzheimer’s. Each of those five kinds of lesions is apparently driven by its own pathologic process. . . . All are independent. . . .

White’s research was presented in a plenary session at the American Academy of Neurology’s 63rd Annual Meeting in Honolulu in April, 2011.

You might stop and ask a question that perplexes most people: What’s the difference between dementia and Alzheimer’s? Aren’t they the same?

In fact, no; so glad you asked.

As defined by Geriatric Care Management, dementia refers to a cluster of symptoms.

These symptoms include: short-term memory loss, poor judgment, difficulty performing familiar tasks, etc. When a person develops these symptoms, it is often a sign that something is wrong inside the brain.

Dementia can be caused by any number of reversible reasons: sleep apnea, depression, vitamin deficiency, temporary lack of oxygen to the brain, being over-medicated.

Often dementia is stopped in its tracks when these issues are addressed.

If it’s not due to a reversible reason, then it’s time to look at the 3 causes:

1. Alzheimer’s Disease: The leading cause of dementia is AD, was once believed to account for up to 70% of dementia cases, thus becoming, in the lexicon, often synonymous. It may, given new research findings, be closer to around 50%.
2. Vascular Dementia: Accounting for around 30% of all cases, high blood pressure and high cholesterol join forces to account for irreversible confusion.
3. Lewy Body Dementia. The Lewy Body Dementia Association, asserts that  dementia with Lewy bodies may account for up to 20-25% of people with dementia. The term Body Dementia (or LBD) covers two related diagnoses:  ‘Parkinson’s disease dementia’ (which can occur in the end stages of Parkinson’s disease) and ‘dementia with Lewy bodies’ (meaning that Lewy bodies, or proteins that abnormally clump together inside neurons and cause degeneration of  brain cells, are present and cause deterioration).

And other, less common causes, for dementia exist as well.  See:

•  “Often Misdiagnosed as Alzheimer’s Disease, Chronic Traumatic Encephalopathy Could Play a Role in Veterans’ Dementia,” or
• “Treatable Condition Can Be Misdiagnosed As Alzheimer’s,” which discusses Normal Pressure Hydrocephalus, or NPH, one of the very few treatable causes of dementia (and with an estimated 400,000 impacted), or
• “Conditions With Symptoms Similar To Alzheimer’s That Could Cause A Misdiagnosis” which discusses:
  • Multi-infarct dementia (MID) which occurs when a person has multiple strokes in the brain, which leads to insufficient blood supply to the brain, and thus deterioration of brain tissue, as well as
  • Huntington’s Disease, and
  • Creutzfeldt-Jakob Disease.

As far back as a 1993 article in the Journal of Geriatric Psychiatry and Neurology took a look at 8 cases diagnosed as Alzheimer’s that were discovered–in the pathology lab–to be no such thing. The researchers determined that each of the misdiagnosed people presented with symptoms that were atypical of AD–yet received the diagnosis anyway.

To me this indicates the tendency to  rush to diagnose AD so often when dementia symptoms occur–even if the diagnostic criteria are not a perfect match–without searching for other causes behind the presentation.

Other researchers found, as far back as 1988, that of 13 elderly patients diagnosed with AD, only 6 actually met the criteria according to brain lesion measurement after death. Vascular dementia, on the other hand, might be subject to serious under-diagnosis.

In an article with a provocative title, “Vascular dementia may be the most common form of dementia in the elderly,” author Gustavo Roman argues that, indeed, vascular dementia is so under-diagnosed that, if properly assessed, it could potentially rival AD for sheer numbers of sufferers.

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So this all might yield the question that so much fascinating information inspires: Who cares?

If the symptoms are similar, if the misdiagnoses are merely other forms of dementia, untreatable as yet, why should we worry if someone is labeled with Alzheimer’s as opposed to, say, vascular dementia? How would the response would be different if a patient knew a different cause underlay their confusion?

It’s a good question–with some good answers [the first two addressed by “the best name in news.” See CNN’s related article, Half of Alzheimer’s cases misdiagnosed].

First, because of a heredity component in Alzheimer’s as opposed to the other forms of dementia, knowing if a family member has the illness can help others determine their risk, and perhaps think differently about their own future care options.

Second, we really must know who has Alzheimer’s if research on treatments is to have any accuracy. Testing an Alzheimer’s drug on a patient with vascular dementia merely skews the results, and prevents the drug company from truly assessing how effective their treatments are.

At times the flu and the common cold present with similar symptoms, for example–but testing a medication for the flu on someone with the sniffles is worse than a waste of time–it invalidates the entire testing procedure.

Finally, I believe, there is a limited amount of research money, despite what it may sound like when we hear about the size of grants. The Alzheimer’s lobby is powerful, and takes up a large chunk of funding. The money goes to a good place, and I do not begrudge it.

But other forms of dementias need research too, for better diagnosis and treatment, and if they are so much more prevalent than previously thought, they deserve a commensurately larger piece of the funding pie.

If studies continue to confirm that diagnoses of AD are in fact other forms of dementia, there may very well need to be a reshuffling of research dollars–and even of public awareness campaign money.

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Sadly, as of yet there’s no way to distinguish between certain dementias except in the pathology lab.

But what if research could discover a way to determine from which dementia a patient was suffering–and, then, down the line, actually do something to slow progression of the symptoms, perhaps something different for those with AD than for those with MID than for those with NPH?

Wouldn’t it be nice for the 50% of people who might be have been misdiagnosed with the illness not to hear the prognosis “Alzheimer’s Disease” unnecessarily?

And wouldn’t it be nice, as well, as diagnosis became more accurate, for Alzheimer’s to fall a few notches from its place as the 5th most common illness? It just might happen, if we could more accurately figure out what was causing people’s dementia.

I believe it’s possible, one day, to get to a place where doctors don’t have to say, along with good old Britney Spears, when doing an autopsy on a patient they misdiagnosed with AD:

“Oops, I think I did it again.”

 

REFERENCES

American Academy of Neurology. “Alzheimer’s disease may be easily misdiagnosed.” ScienceDaily, 23 Feb. 2011. Web. 20 May 2012.

Americans Worry About Getting Alzheimer’s (http://www.webmd.com/alzheimers/news/20110223/americans-worry-about-getting-alzheimers)

Homer AC. Diagnosing dementia: do we get it right? British Journal of Medicine 1988; 297:894-8.

McDaniel LD, Lukovits T, McDaniel KD. Alzheimer’s Disease: The Problem of Incorrect Clinical Diagnosis. Journal of  Geriatric Psychiatry and Neurology 1993; 6(4):230-234.

Roman G. Vascular dementia may be the most common form of dementia in the elderly. Journal of the Neurological Sciences 2002; 203:7-10, 15.

Related articles

• What Causes Dementia (allthingsdementia.com)
• Diagnosing Dementia (allthingsdementia.com)
• Vascular Dementia Stages (allthingsdementia.com)