We have talked before in this column about the fact that there are many different disease processes that can cause dementia. Dementia is the general term that describes a loss of brain function that affects memory, thinking, language, judgment, and behavior.

Some of the more common types of dementia include Alzheimer’s disease, vascular dementia and Parkinson’s dementia. Another fairly prevalent type of dementia, though not frequently diagnosed, is Lewy Body dementia (also called dementia with Lewy Bodies)

Lewy Body Dementia, like the others, is a progressive neurological disorder. It is characterized by abnormal deposits of a protein (alpha-synuclein) that form inside the brain’s nerve cells. Lewy Body dementia is typically diagnosed by looking at a patient’s symptoms (and first ruling out any other medical causes for them). According to the Lewy Body Dementia Association (www.lbda.org), the diagnostic criteria requires a person to have dementia plus only TWO of any of the following: hallucinations, parkinsonism, fluctuating cognitive abilities, REM sleep behavior disorder, a severe sensitivity to antipsychotic medications, or an abnormal result on a brain scan that detects levels of dopamine.

Hallucinations are false perceptions that involved the senses. Typically in LBD, the hallucinations are visual. A person may see something that isn’t present, a face in a window, and animal on the floor, a person in the room. Hallucinations can also be auditory (hearing things that aren’t there). Hallucinations do occur in other types of dementia, like Alzheimer’s, but often in later stages of the disease, as opposed to early on in LBD.

Parkinsonism is the presence of symptoms typical to Parkinson’s disease, which include rigidity or stiffness, shuffling gait, tremor and slowness of movement. It could also include problems with balance and resulting falls. Again, some of these symptoms can be seen in other dementias, though often not until more advanced stages.

“Fluctuating cognitive abilities” means that a person with LBD may have significant and unpredictable changes in concentration and attention from day to day. Again, a person with other types of dementia may have some days that are better than others, but in LBD, these fluctuations are more pronounced.

REM sleep behavior disorder involves acting out dreams, sometimes violently. A person with LBD may experience other sleep issues as well, including excessive daytime sleepiness or periods of just staring in to space.

One of the tricky features of LBD is a severe sensitivity to antipsychotic medications. Before a diagnosis of LBD is made, these medications are often prescribed to address the hallucinations and other behavioral symptoms. Someone who has Lewy Body dementia is likely to react to these medications much differently than someone with another type of dementia.

It is particularly for this reason that a good diagnosis is critical. Your doctor will rely on medical testing, like blood work and brain scans, to help narrow the diagnosis. But your descriptions of behaviors and symptoms will be equally important as the doctor tries to determine the type of dementia that your loved one may have.

You can learn more about the various types of dementia at www.alz.org, and http://www.ninds.nih.gov/index.htm. The Lewy Body Dementia Association also has an excellent web site where you will find more information about the disease, including caregiver resources and resources that you can share with your doctor if he or she is not familiar with the disease. You can find them at www.lbda.org.

Christina Forbes, LGSW from the Daybreak Newsletter 8/2011