Early Stage or First stage: Preclinical Alzheimer’s disease
This stage is for research purposes only and will have no effect in your doctor’s office. The idea is that patients could be developing Alzheimer’s, even when they are free of cognitive or memory problems.
This stage is to help researchers determine whether there is a biological change caused by Alzheimer’s that can be detected through blood, spinal fluid test or neuroimaging. Right now, there is no test that accurately predict whether a person will develop Alzheimer’s disease.
While studies show that Alzheimer’s patients experience changes in the brain — the buildup of amyloid protein tangles and nerve cell changes — it is unknown whether this means an inevitable progression to Alzheimer’s dementia.
The disease begins in the hippocampus, then spreads to the frontal temporal lobe affecting recent memory, learning of new information, thinking, planning and organization.
Mid Stage or Second Stage: Mild cognitive impairment (MCI)
Long before a person gets an Alzheimer’s diagnosis, he or she may show small changes in memory, behavior and thinking. This is called mild cognitive impairment.
While it does not cripple a person’s ability to function throughout the day, these differences are often noticed by friends and family members. The disease moves further into the frontal temporal lobe and into the occipital and parietal lobes affecting sensory perception, communication, behaviors, impulse control, judgment and attention to personal appearance.
Some patients in this stage are already observed by their doctors as “probable Alzheimer’s.”
This is a gray area because not all memory problems are Alzheimer’s-related. Cognitive difficulties could stem from other factors such as a drug’s side effects or vascular disease.
There are no blood or medical tests available in doctors’ offices to confirm whether the mild cognitive impairment is because of Alzheimer’s.
Late Stage or Third stage: Dementia because of Alzheimer’s
This is the stage when memory, thinking and behavioral symptoms have become so damaging that the patient’s ability to function is hindered.
In the final stages the disease spreads throughout the brain and affects the ability to recognize anyone, including themselves, to control bodily functions and to eat and drink. Eventually, the brain can no longer tell the body what to do.
This is the stage that people are most familiar with. The patient eventually becomes unable to carry out basic daily tasks — eating, bathroom-related functions and is fully dependent on others for basic care.
The disease is not solely restricted to memory problems. The new guidelines include other symptoms such as difficulty finding words, visual and spatial problems, impaired reasoning and judgment.
- Experienced clinicians can accurately diagnose dementia 90% of the time.
- Accurate diagnosis is critical. Some conditions that cause symptoms of dementia, such as hormone imbalance, vitamin deficiency and infections, can be reversed. For irreversible dementia, treatment options vary depending on the disease.
- Obtaining a proper diagnosis involves consulting with a healthcare professional who is an expert in dementia, and communicating symptoms and experienced in testing.
- Diagnostic tools: include a complete medical history; blood, urine or other medical tests; neuropsychological tests that measure memory, problem solving, attention, and language; and brain scans.
- Individuals with clinically diagnosed dementia have clear cognitive loss in two or more intellectual domains, such as amnesia (loss of memory) and aphasia (inability to communicate effectively), but almost all individuals with Alzheimer’s disease demonstrate short-term memory impairment.
- Other types of dementia may begin with a slow loss of memory function; however, a careful clinical evaluation will usually provide information that suggests dementia other than Alzheimer’s disease.