Clinical diagnosis---etc

Clinical diagnosis

A physician can use a number of different tests to assess memory skills, and, combined with any observed changes in the individual's behavior, they can help make a diagnosis of Alzheimer disease. Other tests that are important in diagnosing the disorder can involve laboratory tests that require blood and urine or imaging studies of the brain. By using neuroimaging studies such as magnetic resonance imaging (MRI) scans, physicians have found that patients with Alzheimer disease often have diffuse atrophy (weakening or decrease in size) in a specific area of the brain called the cerebrum.

Genetic diagnosis

It has been shown that there is a significant association of a specific gene called APOE e4 with the development the early-onset form of the disease. There are three different types of Alzheimer disease that have been shown to be caused by mutations in three distinct genes known as APP, PSEN1, and PSEN2. However, determining the genotype (whether a patient carries this associated mutation) is not entirely conclusive. Currently, although APOE e4 mutation analysis can help in diagnosing a patient suspected of having Alzheimer disease, it is not used for predictive testing of these individuals.

Biochemical markers

Although there are no tests to definitively diagnose Alzheimer disease, there are useful biochemical markers that can help distinguish Alzheimer disease from other disorders that involve dementia, including dementia caused by vascular disorders, drugs, or thyroid disease. Fluid that is found in the brain and spinal cord called cerebrospinal fluid can be tested for levels of two proteins, Tau and A[.beta]42, in patients that develop symptoms of dementia. A[.beta]42 accumulation in the brain is associated with reduced levels in the cerebrospinal fluid. Accumulation of the Tau protein in the brain is associated with Alzheimer disease. Therefore, increased Tau protein levels and decreased A[.beta]42 in the cerebrospinal fluid can pinpoint which persons have Alzheimer disease, regardless of the cause or the age of onset.

The score for these tests is numerical and relies heavily on a reference range determined by a patient's age, sex, and the type of equipment used to perform the test. A positive result will only indicate that a patient is at high risk of having Alzheimer disease and requires further analysis for an accurate diagnosis. This test has yet to be widely performed and is, therefore, only available in certain reference laboratories.

Treatment team

Initially, a physician usually recommends counseling by a psychologist or a support group experienced with this disease. After the diagnosis, visits to the physician focus on treating mild behavioral changes such as depression. Eventually, treatment requires 24-hour supervision and nursing care. The caretakers are mostly nurses or professionals who are part of various assisted-living programs.