Psychological Testing for Dementia and Alzheimers

I have written a little already about psychological testing in general.  One of the types of testing which I mentioned is testing for dementia.

People often confuse dementia and Alzheimers.  Alzheimers disease if a form of dementia.  Often, it is difficult to tell the difference between Alzheimers and other forms of dementia.  What are the other types?  Ischemic dementia involves disease of the small blood vessels of the brain, with occlusions (or blockages) starving brain cells and causing small areas of death.  The areas may be small, but the process is occurring over and over.  Ischemic dementia is also called white matter disease (because the small strokes are occurring in the deep whtie matter) or multi-infarct dementia (because of the repeated small infarcts, or strokes).  Sometimes multi-infarct dementia can be detected by the "spotty" pattern of results.  That is, a patient does well in some areas and poorly in others, rather than doing poorly across the board on cognitive tests.  There are other dementias as well.  Frontotemporal dementia is somewhat different from the other dementias because its meain features are problems with impulsivity and executive functions.

Here is a basic dementia battery that I generally use:

Clinical interview--There always has to be a clinical interview.  And there generally needs to be collaborative information from family, radiological results, nursing staff, etc. The clinical interview needs to rule out other possible causes of memory loss and cognitive dysfunction besides dementia, such as severe depression, anxiety, medication effects, and so.  The interview also looks at current medications, history of head trauma, alcohol and drug abuse, and so on.

My own habit is to look next at the Geriatric Depression Scale.  I always want to know next how depressed the person is, mainly because severe depression can cause memory problems.  On the other hand, cognitive problems can cause people to become depressed, either psychologically depressed, or through more direct biochemical pathways.

For a cognitive screening, I use the Dementia Rating Scale.  Many people use the Mini Mental Status Exam (MMSE).  I find that the DRS gives a better screening.  It looks at attention, initiation of tasks, graphomotor functioning, abstract thinking, and memory.  By the time the DRS is over, I have a rough idea of whether the person is actually having any significant cognitive problems or not.  If so, I don't know what is causing them; I just know whether there are any gross problems.

I look at spatial functioning using a simple clock drawing test, and I look at ability to find words using the Boston Naming Test.  A straightforward verbal list learning test is also part of my screening batter.  If the dementia is severe, sometimes this simple battery is all that I need to answer a referral question.  If the cognitive impairment is less severe or uncertain, or if very specific information is wanted, I use a longer battery of tests.

For example, I use the Wide Range Assessment of Memory and Learning-2 to assess verbal memory, visual memory, attention, delayed recall, and recognition memory.

The Wechsler Adult Intelligence Scale-IV is an IQ test, but IQ is not really what we are looking for here.  We are looking at the pattern of results.  There are some patterns more suggestive of dementia than others.  Verbal abilities such as vocabulary tend to remain at the same level during cognitive decline compared to the loss of perceptual organizational abilities.  The IQ test allows us to look at such patterns.

If I suspect a frontal lobe problem, then there is a test which includes several tasks measuring frontal lobe functioning.

What else could be done?  Well, there are other tests, but in my experience the above tests usually provide the information which is needed for diagnosis.

Followup to the testing involves a feedback session with the patient and their family.  The main question which they usually have is whether the memory loss is permanent and whether there is any treatment for it.  I usually tell them to talk with the psychiatrist, but I tell them that most dementias do not get better.  (Some insults to the brain, on the other hand, do heal.)  I talk with them about medication being available for some dementias.  I also talk with them about maybe seeing a rehabilitation psychologist to help them learn ways of improving memory, or if not improving it, at least compensating for memory problems.