Mild Cognitive Impairment

Diagnosis

No test can detect mild cognitive impairment. Instead, the disorder is diagnosed by excluding other conditions that might be causing the signs and symptoms. Because of this, there are numerous tests and questions for each patient.

The patient will first have a complete physical exam, along with a detailed history of symptoms and medical history, including medications. Examination by neurology specialists will help identify signs of Parkinson's disease, strokes, tumors and other medical conditions that may impair memory and thinking, as well as physical function. Some tests that may be given are described below.

Mental Status and Neuropsychological Assessments

To determine which thinking and memory functions may be affected and to what degree, the patient will be asked questions to measure cognitive functions for attention, learning, recall, language and visuospatial abilities. The tests are compared to the tests of others of similar age and education.

The patient and people familiar with the patient will be interviewed about the patient's emotional state and day-to-day routines. They will also be asked about possible alcohol or drug abuse, head trauma and other causes for memory loss. Family members or close friends can provide valuable information about changes in the patient's behavior and personality.

Psychiatric Assessments

In addition, the patient may have a psychiatric assessment to uncover if depression or other mental illness is present.

Blood Tests

The patient's blood sample will be checked for infections or conditions such as vitamin deficiency, anemia, medication levels, disorders of the thyroid, kidneys or liver, and other factors that can cause memory loss.

Brain Imaging

Tests of internal images of the brain help detect strokes, tumors or other conditions that may have affected the brain, and may show changes to structures in the brain that are associated with memory, such as the hippocampus. Mayo Clinic uses the following brain imaging techniques:

• Computed tomography (CT scan)— In this test, an X-ray machine rapidly rotates around the brain using a series of thin X-ray beams to produce two-dimensional images of the brain.
• Magnetic resonance imaging (MRI)— This test uses powerful magnets and radio waves to produce a detailed, three-dimensional view of the brain.
• Positron emission tomography (PET) or Single-photon emission computerized tomography (SPECT) — These two fairly new techniques may be needed for clinical-related or research-related study. For both tests, a small amount of radioactive material is injected into the patient and then detectors are placed on the brain to detect emissions. PET provides visual images of activity in the brain. SPECT is used to measure blood flow to regions of the brain.

Most patients will be asked to undergo an MRI scan. In some patients, one of the other types of scans may be performed. The physicians with whom you meet can discuss which tests are most appropriate to establish the correct diagnosis.

Other Tests

Other tests that sometimes provide important diagnostic information include an electroencephalogram (EEG), electromyogram (EMG), urine tests, and tests on the cerebrospinal fluid (CSF) obtained by a lumbar puncture. The physicians discuss with the patient and his/her family which tests are most appropriate to establish the correct diagnosis.