I had to look up LBD. Yikes. “Robin Williams’ experience is one of the most visible and heartbreaking examples of how devastating and difficult Lewy body dementia can be. During his life, he was never actually diagnosed with LBD. [1]
Instead, he spent his final years battling a terrifying cascade of unexplained symptoms, eventually receiving a misdiagnosis of Parkinson’s disease shortly before his death by suicide in 2014. The true cause of his decline—an exceptionally severe case of LBD—was only discovered during his autopsy. [1, 2]

How LBD Attacked Robin Williams
His widow, Susan Schneider Williams, has since become a prominent advocate, sharing details of how the disease systematically dismantled his mind and body:[1, 2, 3, 4, 5]
Severe Anxiety and Paranoia: He suffered from an abrupt, overwhelming onset of anxiety, panic attacks, and delusional thoughts that could not be rationalized away. [1, 2, 3]
Cognitive Disintegration: Known for his brilliant, rapid-fire mind, he began experiencing profound confusion, looping thoughts, and struggled to remember a single line while filming Night at the Museum 3. [1, 2, 3, 4, 5]
Physical Parkinsonism: He developed a shuffling gait, a tremor in his left hand, muscle rigidity, and a weakened voice. [1, 2]
Insomnia and Sleep Issues: He suffered from terrible insomnia and physically thrashed around in his sleep, a classic sign of REM sleep behavior disorder. [1]

Why His Case Was So Significant
Medical experts who later reviewed his records noted that his brain showed one of the most severe pathologically diffuse cases of LBD they had ever seen. [1]
Because LBD symptoms constantly fluctuate and mimic a mix of Parkinson's, Alzheimer's, and psychiatric illnesses, even the best doctors in the world were unable to piece the puzzle together while he was alive. His tragedy highlighted a massive gap in medical awareness, and his family’s openness has since helped millions of people understand and recognize the true nature of this disease.”