Dementia
Alzheimer’s disease is a type of dementia meaning that it involves impairment in memory and one other cognitive domain. Typically this will involve impairment in one or more of the following: visuospatial processing, language, executive functioning (complex decision making), emotional regulation, and orientation.
A test called the Mini Mental Status Exam (MMSE) was designed to measure the progression of Alzheimer’s disease and tests these domains. See the section on this test below for more details.

Alzheimer's Disease
Alzheimer’s disease is a degenerative disease of the brain that affects approximately 5 million people in the United States. It is estimated that by the year 2030 more than 65 million people will be diagnosed with Alzheimer’s worldwide. Currently, Alzheimer’s disease is a clinical diagnosis, meaning that there is no confirmatory test that can definitively determine whether a person has it, other than tests of brain tissue that can only be performed after death. Although the exact mechanism by which Alzheimer's disease progresses is poorly understood, it is known that "plaques" formed of a subsance called beta-amyloid accumulate in the brains of invidual's with the disease and the extent of these plaques correlates with the severity of symptoms. These plaques are the hallmark of Alzheimer's disease. Traditionally they have only been identifiable by examination of the brain after death; however, new neuroimaging techniques are being developed that may be able to reveal these plaques early in the progression of the disease, allowing for earlier detection and better treatment outcomes.

Alzheimer's Symptoms
The symptoms of Alzheimer’s disease result from damage to a region of the brain called the mesial temporal lobe. In this region is a structure called the hippocampus which is involved in the formation of new memories. The hippocampus functions something like the recording head of a tape recorder; when it becomes damaged, no new information can be recorded. So in Alzheimer’s, old memories that were formed before the onset of the disease remain intact but new memories cannot be made. This is why individuals with Alzheimer’s often can remember events from the distant past in great detail but cannot recall events that occurred yesterday.  Other important neural structures are located in the mesial temporal lobe as well and damage to this region in Alzheimer’s results in varied but characteristic deficits. Below is a list of the 10 most common early symptoms of Alzheimer’s disease.

• Memory loss
• Difficulty planning or problem solving
• Difficulty completing familiar tasks
• Loss of orientation to time or place
• Difficulty with visual processing and spatial relationships
• Language difficulties
• Misplacing objects
• Impaired judgment
• Social withdrawal
• Personality changes

Alzheimer's Treatment
Currently there is no cure for Alzheimer’s and the medications that are available typically only slow the progression the progression of the disease rather than reverse it.  Nonetheless, there is a tremendous amount of research currently being done and there are new diagnostic and therapeutic technologies being developed. Early detection of Alzheimer’s is important as beginning medication earlier in the course of the disease may prolong functionality and quality of life.
Pharmacologically, there are two classes of drugs that are used to treat Alzheimer’s. The most commonly used class is called acetylcholine esterase inhibitors. These medications prevent the breakdown of acetylcholine, a neurotransmitter with low levels in Alzheimer’s. The other class of medication is NMDA antagonists. Currently there is only one medication in this class that is used for Alzheimer’s and it is called memantine or Namenda. This drug fits into the same receptors in the brain as a neurotransmitter called glutamate and prevents the receptor from firing.
Behavioral interventions for Alzheimer’s such as frequently reorienting the individual and keeping their environment stable and familiar are often very effective as well, particularly for decreasing agitation in the later stages of the disease.

Mini Mental Status Exam
The Mini Mental Status Exam is frequently used by physicians to screen for Alzheimer’s dementia and to assess its severity. The test is scored out of 30 and tests the cognitive domains most affected by Alzheimer’s (see above). Although the test was once widely distributed for free, it is now copyrighted and technically permission must be obtained from the copyright owner to publish it. Nonetheless, it is widely available on the internet, e.g. at http://www.nmaging.state.nm.us/pdf_files/Mini_Mental_Status_Exam.pdf.  A score of 24-30 is consistent with no cognitive impairment, a score of 18-23 is consistent with cognitive impairment, a score of 0-17 is consistent with moderate to severe cognitive impairment

Additional Resources
Alzheimer's Association, The Mayo Clinic, Medline