The development of Alzheimer’s dementia is a gradual process (or transition) and not a sudden event. Most affected patients transition through a phase called mild cognitive impairment (MCI), an intermediate stage between the normal expected cognitive decline of aging and the more serious decline of Alzheimer’s dementia.
MCI patients have problems with memory, language and judgment that are greater than normal age-related changes, but they do not have dementia.
Affected patients might forget important events such as appointments or social engagements, lose their train of thought in conversations, feel overwhelmed making decisions, or have trouble finding their way around familiar environments. Family members may notice that their memory has “slipped”.
Although they might need to use written notes or other reminders to cope at home or at work, MCI does not prevent them from performing their day-to-day life activities.
MCI is a risk factor for developing Alzheimer’s in the future, just as high cholesterol is a risk factor for developing heart disease.
MCI patients will develop Alzheimer’s disease at a rate of about 12%/yr, more than ten times the rate of the general population. If you start out with 100 patients, 12 will have developed Alzheimer’s by the end of the first year, 24 by the end of the second year, 36 by the end of the third year and so on and so forth. The onset of Alzheimer’s is defined when the memory and behavioral problems of MCI get bad enough to affect daily activities.
Cognitive screening for MCI and Alzheimer’s dementia is one component of Medicare’s new annual wellness visit, and healthcare providers will be required to administer a brief screening test such as the Mini-Cog, the Memory Impairment Screen (MIS), or the General Practitioner Assessment of Cognition (GPCOG) during that visit. An abnormal result on the screening test will identify patients with MCI, at risk for developing dementia, who can then be sent for further testing.
Their are 2 FDA has approved classes of medication for the treatment of Alzheimer’s dementia. The cholinesterase inhibitors donnepezil (Aricept), rivastigmine (Exelon) and Galantamine (Razadyne) are approved to treat mild to moderate Alzheimer’s. Memantine (Namenda) is approved for treatment of moderate to severe Alzheimer’s. There are no currently approved drugs for the treatment of MCI, and although many doctors do prescribe medications approved for Alzheimer’s dementia “off label”.
MCI is an area of active research: Clinical studies are under way to find treatments that may improve symptoms or prevent or delay progression to dementia. Furthermore, because new treatments for Alzheimer’s are likely to be more effective early in the course of disease, there is considerable interest in identifying theses high risk MCI patients before they develop Alzheimer’s dementia.
CLick here for a recent post about diagnostic testing in MCI and Alzheimer’s disease.