Specialized Tests - When To See A Doctor: Improving Memory Understanding Age Related Memory Loss

Content provided by the Faculty of the Harvard Medical School

Specialized tests

Your doctor will probably refer you to a specialist for more testing if your examination and initial test results suggest the possibility of a neurological or medical disorder.

Brain-imaging tests

An MRI or CT scan produces a structural image of your brain. These imaging methods provide the most definitive method of identifying certain causes of memory problems, such as a brain tumor, hydrocephalus (an abnormal accumulation of cerebrospinal fluid within the ventricles of the brain), or a subdural hematoma (a collection of blood under the surface of the skull). All of these conditions cause increasing pressure within the brain, producing neurological and cognitive symptoms. Treatment for these conditions is often successful, particularly if they are detected early.

Although each new generation of MRI scanners is more sensitive than the one before, the types of structural changes in the brain characteristic of very early Alzheimer's disease are quite subtle, and may not be easily detectable with current MRI technology. If your structural imaging is normal, your doctor might arrange for you to undergo a SPECT scan or a PET scan. In contrast to MRI and CT, which evaluate the physical structure of the brain, SPECT and PET scans evaluate how well your brain is functioning by tracking either blood flow or metabolic activity. A decrease in blood flow or energy metabolism in the temporal and parietal regions of the brain is frequently seen in Alzheimer's disease, and functional imaging can reveal these abnormalities, even when the MRI or CT is apparently normal. (For more on imaging methods, see "Watching the brain at work.")

Last updated:	January 23, 2007