Diagnosis Of Alzheimer’s Disease – Neuropsychological Testing

In addition to the standard psychological/psychiatric evaluation described above, neuropsychological testing may be conducted to determine more specifically the type and level of cognitive impairment people are exhibiting, as well as their strengths and preserved abilities. Information about preserved abilities is important to help form a treatment plan and recommendations about environmental modifications that would be useful (e.g., job modifications, looking for a more supportive living environment, etc.).

Neuropsychologists administer tests that have been developed through rigorous research in order to study people’s short- and long-term memory, attention, concentration, reasoning, and ability to solve problems and learn new information. Tests results are compared to performance of other individuals of the same age and education level to determine whether a specific individual is impaired.

A variety of tests are available that can narrow the range of possible diagnoses by identifying patterns indicative of Alzheimer’s, head injury, stroke, or other conditions. For example, someone with a head injury may exhibit amnesia (an inability to learn and recall new information and/or problems remembering previously learned information or past events) as the most prominent symptom, while someone with Alzheimer’s will show short-term memory impairment, but not necessarily amnesia. A neuropsychologist might administer one test or a whole battery of them, depending on the individual. Potential neuropsychological tests used to assess for AD include:

ADAS-Cog (Alzheimer’s Disease Assessment Scale-Cognitive): This is an 11-part test that takes 30 minutes to complete and is considered more thorough than the MMSE screening tool described above. The ADAS-Cog focuses on attention, orientation (knowing who you are, where you are, and what time it is), language, executive functioning (the ability to plan, make decisions, and carry out daily tasks), and memory skills.

Behavioral Pathology in Alzheimer’s Disease Rating Scale (BEHAVE-AD): This test provides a global rating of behavioral symptoms such as verbal aggression, physical aggression, and hyperactivity. In addition to diagnosis, the scale is often used when clinicians want to determine how well medications are working to manage someone’s behavioral symptoms.

Blessed Test: This is one of the oldest tests designed to assess for Alzheimer’s Disease and takes only 10 minutes to complete. The Blessed Test assesses memory, attention, concentration, and the ability to complete activities of daily living, or ADLs (i.e., bathing, dressing, grooming, eating).

CANTAB (Cambridge Neuropsychological Test Automated Battery): This test includes 13 interrelated tests of memory, attention, and executive functioning (planning and sequencing to solve complex problems). The battery is administered through a computer by using a touch-sensitive screen. Research has shown the battery to be largely unbiased in regard to language and culture, as well as quite sensitive to the early signs of Alzheimer’s Disease.

Clock Drawing Test: Often used in combination with other neuropsychological tests, the Clock Drawing Test assesses visual-spatial impairment (problems with the ability to perceive objects correctly as well as the relationship between objects; e.g., people with visual-spatial impairment may have trouble parking a car because they cannot correctly perceive where the car is in relation to the vehicles surrounding the empty parking space). Testees are asked to draw the face of a clock, including all of the numbers. They are then asked to draw clock hands which show a certain time (e.g., “10 minutes after 11”).

Cognistat (Neurobehavioral Cognitive Status Examination): This test assesses intellectual functioning in five areas: language, construction (i.e., the ability to copy or assemble items in a two- or three-dimensional space), memory, calculations, and reasoning/judgment. The test takes approximately 10 minutes when people show no cognitive impairment; for those who are cognitively impaired, the test can take up to 20-30 minutes.

Dementia Rating Scale – 2 (DRS-2): This is a 15-20 minute measure of cognitive impairment, which yields scores in five areas: attention, initiation/perseveration (i.e., the ability to start or stop doing a task), construction, conceptualization (interpreting what is seen, heard, etc., into an idea or a conclusion), and memory.

Neuropsychiatric Inventory (NPI): This test assesses 12 behavioral problems that commonly occur in people with AD and other dementias, including agitation, anxiety, apathy, delusions (fixed, false beliefs), hallucinations (sensing things that are not really there), euphoria (i.e., extreme happiness or elation), dysphoria (i.e., the opposite of euphoria), eating difficulties, loss of inhibition (the ability to hold back an extreme emotion or behavior), irritability, irregular motor behavior (e.g., shaking or trembling in just the hands or another body part), and sleeping disturbances.

Obviously, diagnosing Alzheimer’s is a complex process because the physician (or team of health care professionals) has a great deal of information to sort through. If a diagnosis of Alzheimer’s is made, the next step is to then begin treating the disease and symptoms. As previously explained, there is no cure for AD. However, there are some treatments and approaches that can sometimes improve symptoms and/or quality of life. The first stage of treatment is typically to address the person’s cognitive symptoms with one or more of the medications described below. Although these drugs can be helpful, they cannot stop or reverse the disease, and eventually, the brain damage will “win.” The second stage of treatment is to address the person’s environment or surroundings in order to maximize the person’s functioning. Methods for shaping the environment to be “AD friendly” are also described below.