There is no straightforward medical test for Alzheimer’s. If this is suspected, your doctor will do tests to rule other possibilities, such as vitamin deficiencies, thyroid gland problems, depression, side effects of medication, infections and brain tumours. Once these are excluded as the causes of your symptoms then the doctor is better placed to consider Alzheimer’s.
Some things the doctor will do to help diagnose the condition:
They will spend time talking to you (or the person you are concerned about). They will look at the person’s medical history and that of other family members. The way in which the person’s problems have developed is important and usually the doctor will ask many questions about the changes that have occurred in the person in order to help determine that your loved one has dementia and not one of the treatable conditions mentioned above.
They will normally carry out a physical examination and may perform a number of tests, such as blood and urine tests, to identify other conditions that may be causing confusion.
They may ask a series of questions designed to test thinking and memory.
At the end of their assessment, your doctor will let you know their findings and discuss what action needs to be taken. They may decide to refer you to a clinical psychologist for cognitive testing, or a different specialist such as a neurologist, psychiatrist or geriatrician for further tests. After this visit you will return to your doctor who will talk to you about the range of services available. It is useful to know what is available even if you might not need it right now.
Alzheimer’s disease with computed tomography
Alzheimer’s disease is usually diagnosed based on the person’s medical history, history from relatives, and behavioural observations. The presence of characteristic neurological and neuropsychological features and the absence of alternative conditions is supportive. Advanced medical imaging with computed tomography (CT) or magnetic resonance imaging (MRI). And with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) can be used to help exclude other cerebral pathology or subtypes of dementia. Moreover, it may predict conversion from prodromal stages (mild cognitive impairment) to Alzheimer’s disease.
Assessment of intellectual functioning including memory testing can further characterise the state of the disease. Medical organisations have created diagnostic criteria to ease and standardise the diagnostic process for practising physicians. The diagnosis can be confirmed with very high accuracy post-mortem when brain material is available and can be examined histologically.