Researchers from Mount Sinai School of Medicine (USA) have found that people who toss and turn in bed and kick in their sleep may have an increased risk of Parkinson's disease. Such restless sleep may be caused by increased inflammation in the area of the brain that regulates dopamine production. The results of the study are published in the journal Annals of Neurology. According to scientists, frequent body movements in sleep in Parkinson's disease is called rapid eye movement behavior disorder (RBD). Patients with Parkinson's disease and dementia are known to have reduced levels of dopamine, which is involved in regulating the sleep-wake cycle and helps control sleep phases. This happens because the nerve cells in the brain that produce it die off. Researchers have also found that a sleep study known as videopolysomnography can help predict the development of Parkinson's disease. As part of an experiment involving 170 volunteers (80 of whom had the disease), scientists used such sleep monitoring technology. The team analyzed the number of movements the participants made during REM sleep. The scientists then used this data to measure the frequency, ratio, magnitude and speed of movements, as well as the ratio of immobility (restful sleep). The sleep study helped identify individuals with Parkinson's disease with 92% accuracy.