Mild Cognitive Impairment
Mild cognitive impairment refers to cognitive symptoms that are worse than expected for age, but not severe enough to interfere with normal activities or relationships. Like dementia, mild cognitive impairment is a descriptive term and not a specific disease; it also shares with dementia a similar list of possible underlying causes.
It is important to note that neurodegenerative diseases do not start the day that a patient can no longer drive a car, balance a checkbook, or prepare a meal. Instead, the changes that occur in the brain in Alzheimer's disease and other such illnesses begin insidiously, without any outward symptoms at first; patients progress gradually through a stage of mild cognitive impairment and then to dementia, often over a period of years. Frequently, the pattern of early symptoms is evident only in retrospect.
On the other hand, not all patients with mild cognitive impairment ever go on to develop dementia. Much research, including at the Stanford Center for Memory Disorders, focuses on how to determine which patients with mild cognitive impairment will worsen over time, and who will not. Diagnostic tests like advanced neuroimaging and the determination of certain protein levels in the blood and cerebrospinal fluid may yield valuable predictive information.