JOURNEY TO THE CENTER OF THE BRAIN:

FROM DEVELOPMENT TO DEGENERATIVE DISEASE

Audience Q & A

Question:  Is there any correlation between mental illness in early life and neurodegenerative disease in later life?

Answer:  First, let’s limit the definition of neurodegenerative disease to the common causes of dementia.  These include Alzheimer’s disease, vascular dementia (due to strokes), and dementia related to Parkinson’s disease.  For these diseases, the answer to your question is clearly “no.”  We know of no epidemiological evidence linking these dementias to mental illness occurring early in life.  Having said that, however, it is important to keep in mind that late-life depression is sometimes associated with Alzheimer’s disease and that depressive symptoms may appear even before memory loss is recognized.

--William Klunk, M.D., Ph.D.

Question:  If the pathology of Alzheimer’s is not subtle, why is it so difficult to diagnose definitively?

Answer:  By definition, Alzheimer’s disease can only be called “definite” after an examination of the brain at autopsy, that is, after death.  The extensive pathological changes in the brain tissue of the Alzheimer’s disease victim are apparent during an autopsy, and a definitive diagnosis is not difficult.  In contrast, diagnosis in the living patient is labeled as “probable Alzheimer’s disease.”  This is done because we cannot presently assess pathological changes in the brains of living patients.

In Alzheimer Disease Research Centers, this “probable” diagnosis is later confirmed as “definite” at autopsy in about 90 percent of cases.  Even so, it would be very helpful to have a tool to measure the brain pathology of Alzheimer’s disease in living patients.  University of Pittsburgh researchers have pioneered the development of this type of neuroimaging tool and hope to apply this imaging technology to human studies.  If successful, this technology could allow us to make a definitive diagnosis of Alzheimer’s disease during the patient’s lifetime.  Ultimately, we may even be able to diagnose this dementia before the first symptoms of forgetfulness appear.

--WK

Question:  Should family members of Alzheimer’s patients get a CT scan to see if they will be affected in future years?

Answer:  Absolutely not.  At this time, no test can accurately predict who will or will not develop Alzheimer’s disease.  This limitation even extends to assessments of specific genes.  However, researchers are actively seeking methods for making these predictions at some point in the future.  Experimental tests involving blood, cerebrospinal fluid (obtained through a spinal tap), and neuroimaging studies of brain function (using magnetic resonance imaging and positron emission tomography scans) are all being evaluated.  None of these can currently be recommended for clinical use.

--WK

Answer:  There have been anecdotal reports on the usefulness of gingko biloba for memory loss, but the evidence is not complete.  The National Institutes of Health has instituted an ongoing, rigorous clinical study to evaluate gingko biloba.  These types of studies are essential in separating “fact” from “fiction.”  The situation is similar for antioxidants, but no formal clinical trial has been instituted to test these compounds to date.

--Robert Y. Moore, M.D., Ph.D.

Answer:  Stem cells are seen as an ideal source of tissue for transplantation for two reasons.  They are pluripotential – capable of producing many different types of cells – and they can be directed to make any kind of cell.  Many scientists believe that stem cells will be used successfully in the future to treat neurological diseases.  However, at the present time, the U.S. Congress has specifically prohibited the use of human stem cells.

--RYM

Question:  How is Alzheimer’s different from senile dementia?

Answer:  Senile dementia is a generic term used to describe loss of intellectual function in the elderly.  The term actually includes a number of disease entities, but Alzheimer’s disease is the most common of these.

--RYM