How to tell if MCI will convert to Alzheimer's Disease?

Contributed by: Dennis Fortier, President, Medical Care Corporation

I commonly encounter this question in the press, I hear it discussed at conferences, and physicians pose it to me on a regular basis. Despite the centrality of this question in so many forums of cognitive health, it is a nonsensical inquiry with inherent flaws. Additionally, it propagates a pernicious brand of confusion that I want to clarify today.

As per my earlier post, Mild Cognitive Impairment 101, there are many medical conditions that can cause a subtle cognitive deficit. Pondering whether or not MCI will "convert" to Alzheimer's Disease (AD) obscures the fact that MCI is a symptom of an underlying medical problem (not the problem itself). In fact, some MCI is actually caused by AD and therefore, the prospect of converting does not belong in a logical, informed discussion.

When MCI is present, the correct question is "what is the cause of the impairment?". If the answer is AD, then the folly of a conversion outcome is clear; the disease precedes the impairment and not vice-versa. If the MCI is caused by some other medical condition (depression, vascular disease, anxiety, etc.) then it is equally futile to consider whether or not it will convert to AD; these medical problems are separate and distinct. That is not to say that such a particular person will never get AD because they may. In fact, the medical condition causing their impairment might even confer a greater risk for AD, but the notion of "converting" from MCI to AD is illogical.

A good analogy would be to learn of a patient with excessive thirst and blurry vision and then wondering if these symptoms will ever "convert" to Diabetes. Most physicians would perform a diagnostic work-up, take note of the high blood sugar, and diagnose diabetes immediately. There would be no debate about whether or not the symptoms would covert to the disease -- they would conclude that the presence of the disease has caused the symptoms. We must do the same with MCI. That is, perform a work-up and identify the underlying cause of the symptoms so that the patient may benefit from timely intervention.

So why have I labeled this as "a pernicious brand of confusion"? Because the perpetration of the idea that MCI might or might not convert to AD prevents some (if not many) primary care physicians from proactively diagnosing the cause of MCI and treating it. Giving any credence to the notion that MCI is a sporadically progressive precursor to AD is a barrier to clarity and interferes with a higher standard of care in this field.

No comments :

Post a Comment