What Is Spectrum Dementia, and What Are the Differences?

What is a spectrum disease?  It’s a mental disorder that includes a range of linked conditions, sometimes also extending to include singular symptoms and traits (Spectrum disorder).    This usually pertains to Autism, but it also refers to Dementia, as well.  

According to the information from the Lewy Body Dementia Association, and the below lecture (sound is awful, but the information is incredible), there is a spectrum of dementia - at one end is Alzheimer’s (AD) and the other end is Parkinson’s Disease (PD).  Lewy Body Dementia falls somewhere in the middle, but there is no definitive point at where it might occur on that line.  

You see, LBD and PD stem from the same cause - alpha-synuclein acids in the brain.  PD is caused by the prevalence in the motor control portion and LBD has the little demons mostly surrounding the cerebral cortex, as well as other portion.   AD is caused by Beta Amyloid plaques in the brain.  AD is so very different from LBD/PD, and yet there is the phenomenon of mixed dementias - in which the LBD patient may have some of the same plaques and tangles of the AD patient, and the AD patient may develop some of the same symptoms as the other.  It’s a rather tangled and confusing issue.

There have been studies performed on locating just where on the spectrum LBD might be found, but they haven’t been able to make any determination (Ballard, C et al. "Differences in neuropathologic characteristics across the Lewy body dementia spectrum." Neurology 67.11 (2006): 1931-1934.).  

Now, the LBDA (Lewy Body Dementia Assn) expresses that the disease (some also state this is more a syndrome than a simple disease) runs a great spectrum of disorders that come together into the form of dementia which has found its way into our lives (The LBD Spectrum).  There is also a good article that does a much better job of articulating in few words than I at Alzheimer's Disease: One Type of Dementia on a Wider ….  While the end is a promotion, you can take the rest into account.

Following is a video which demonstrates (I may have posted it many moons earlier) the differences on the brain of PD, LBD, and AD.  As I stated, the sound is rather horrible, but the information is very intriguing, and I find myself watching it from time to time and learning much more:

This does such a fantastic job of showing the SPECT and PET scans, which are so expensive, that you are able to see the differences of the plighted brains.  There is a great deal of differences between the two ends of the "spectrum" and with LBD, as well. 

I hope I've been able to shed some more light on the topic, for those who might still have questions.