Although doctors have many tools that can assist them in diagnosing a person with Alzheimer's, the disease cannot be fully definitive until after death. This is done by examining the individual's brain tissue and pathology through an autopsy. Once certain structural changes to the brain have been identified, the diagnosis of Alzheimer's can be confirmed.
Despite the fact that a diagnosis cannot be fully obtained until after an individual has passed away, doctors do have several tools and resources available to them to assist in making an initial diagnosis. These diagnostic methods include:
- Physical exams: These tests are completed first to assess the patient's overall neurological health. Reflexes, muscle strength, sensory functions, coordination and balance are all tested during the physical exam.
- Neuropsychological testing: These tests are used to further determine a patient's mental status. Memory, problem solving and other skills are tested through a series of questions and tasks.
- Lab tests: Blood work is typically required in order to rule out other possible causes of Alzheimer's-like symptoms such as memory loss or confusion since these could be the result of a thyroid disorder or vitamin deficiency.
- Brain imaging: Computed tomography (CT), positron emission tomography (PET) and magnetic resonance imaging (MRI) are used to exclude other causes of dementia in the brain like a brain tumor or stroke.
Alzheimer's disease requires extensive testing in order to diagnose. However, these advanced tools have allowed doctors to give a diagnosis at earlier stages of Alzheimer's, allowing patients to begin treatment earlier and thereby slow down the progression of the disease. Even though these diagnoses can only be confirmed after death, doctors are typically correct in their diagnosis of Alzheimer's disease about 90 percent of the time.