There is no specific test to confirm a diagnosis of mild cognitive impairment (MCI). Your doctor will decide whether MCI is the most likely cause of your symptoms based on the information you provide and results of various tests that can help clarify the diagnosis.
Many doctors diagnose MCI based on the following criteria developed by a panel of international experts:
- You have problems with memory or another mental function. You may have problems with your memory, planning, following instructions or making decisions. Your own impressions should be corroborated by someone close to you.
- You've declined over time. A careful medical history reveals that your ability has declined from a higher level. This change ideally is confirmed by a family member or a close friend.
- Your overall mental function and daily activities aren't affected. Your medical history shows that your overall abilities and daily activities generally aren't impaired, although specific symptoms may cause worry and inconvenience.
- Mental status testing shows a mild level of impairment for your age and education level. Doctors often assess mental performance with a brief test such as the Mini-Mental State Examination (MMSE). More-detailed neuropsychological testing may shed additional light on the degree of memory impairment, which types of memory are most affected and whether other mental skills also are impaired.
- Your diagnosis isn't dementia. The problems that you describe and that your doctor documents through corroborating reports, your medical history or mental status testing aren't severe enough to be diagnosed as Alzheimer's disease or another type of dementia.
As part of your physical exam, your doctor may perform some basic tests that indicate how well your brain and nervous system are working. These tests can help detect neurological signs of Parkinson's disease, strokes, tumors or other medical conditions that can impair your memory as well as your physical function. The neurological exam may test:
- Eye movements
- Walking and balance
Blood tests can help rule out physical problems that can affect memory, such as a vitamin B-12 deficiency or an underactive thyroid gland.
Your doctor may order an MRI or CT scan to check for evidence of a brain tumor, stroke or bleeding.
Mental status testing
Short forms of mental status testing can be done in about 10 minutes. In testing, doctors ask people to conduct several specific tasks and answer several questions, such as naming today's date or following a written instruction.
Longer forms of neuropsychological testing can provide additional details about your mental function compared with others' of a similar age and education level. These tests may also help identify patterns of change that offer clues about the underlying cause of your symptoms.