Researchers in the United States have recently found that people who punch and kick during sleep because of dreams related to violence may be a precursor to brain disease. The researchers found that more than 80 percent of people with REM sleep behavioral disorders will later develop neurodegenerative diseases such as Parkinson’s and dementia with Lewy bodies. This finding has important implications for the prevention of diseases such as Parkinson’s and dementia. REM sleep behavior disorders can be manifested as dreams of being attacked, yelling, kicking, punching, and other retaliatory actions that result in injuries to the dreamer or to the person in the bed with the dreamer. The dreamer often wakes up with a clear recollection of the dream accompanied by the fighting behavior. Studies have shown that 0.4% to 0.5% of adults have REM sleep behavior disorders. Carlos Shenk, an expert at the Minnesota Regional Sleep Disorders Research Center, said that tracking those with REM sleep disorders is a good idea. Schenk said that the longer you follow those with REM sleep disorders, the more cases of neurodegenerative diseases you will find.