When news of Robin Williams' suicide spread throughout the country, all of his fans, celebrity and regular folk alike, were devastated and confused. We all asked ourselves and each other: How could such a wonderfully talented man who brought light and laughter into other people's lives have such dark demons that he would feel compelled to take his own life?

Because he was known to battle depression and drug and alcohol addiction, people first attributed his suicide to that, but then we discovered that he was diagnosed with early stages of Parkinson Disease.

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Recently TMZ in an exclusive report shed some more light on what Williams was going through in the weeks and months before his death. Williams according to TMZ was suffering from Lewy Body Dementia which may have contributed to his decision to end his own life.

The Mayo Clinic defines Lewy Body Dementia as "the second most common type of progressive dementia after Alzheimer's disease. It may also cause visual hallucinations, which generally take the form of objects, people or animals that aren't there. This can lead to unusual behavior such as having conversations with deceased loved ones."

This form of dementia is also known to exhibit similar symptoms as those of Parkinson's disease including tremors and rigidity in the muscles.

The Lewey Body Dementia Association (LBDA) offers some further clarification on Williams' autopsy report: "The autopsy indicated the presence of 'diffuse Lewy body dementia' in the brain of Mr. Williams. This is more commonly called 'diffuse Lew body disease' which reflects the biological disease process in the brain."

Dennis Dickson, M.D., Mayo Clinic in Jacksonville, Fla.  and member of the LBDA Scientific Advisory Council however warns that "the use of the term dementia in the neuropathology report should not be inferred to mean that dementia was observed during life."

Lewey bodies found in the brain is associated with both Parkinson's Disease (PD) and dementia with Lewy bodies (DLB).

Generally in a patient in the early stages of PD, the Lewy bodies are not widely spread through the brain, but in DLB they are. Williams' autopsy seems to correspond more to what is found in DLB.

Dr. Dickson having studied the autopsy and coroner's report reported that "Mr. Williams was given a clinical diagnosis of PD and treated for motor symptoms. The report confirms he experienced depression, anxiety and paranoia, which may occur in either Parkinson's disease or dementia with Lewy bodies."

According to LBDA, "both Parkinson's disease with dementia and DLV are considered Lewy body dementias because of the presence of Lewy bodies in the brain."

The main indicators of DLB are cognitive and memory problems that affect a patient's daily functions. While there has been no report that Williams showed these symptoms, that is not so surprising in the early stages. Current tests called Mini Mental Status Exams are limited in their ability to detect signs of early DLB.

Dr. Dickenson believes that "further research is needed to better understand why some individuals with diffuse Lewy body disease do not show symptoms of dementia. In particular, we need to learn how dementia with Lewy bodies differs clinically from Parkinson's disease when they both share the same underlying disease process."

To see a comparison chart between the two diseases, click here.  Learn more at http://www.lbda.org.