Scientists link a ‘certain type of dream’ with dementia and Parkinson’s

Many people experience the odd restless night, but regular abnormal movements or acting out of dreams may be signs of something more serious.

Scientists say REM behaviour disorder (RBD), which occurs during the rapid eye movement phase of sleep, is an early sign of or “in nearly all cases”.

researchers have developed a way to more accurately diagnose the disorder, which affects 80 million people worldwide.

The method involves using an artificial intelligence-powered algorithm to analyse video recordings of clinical sleep tests.

According to findings  Annals of Neurology, it detects RBD with 92% accuracy.

Dreams can be much more vivid during the REM stage, which first occurs around 90 minutes after you fall asleep.

During this stage, people with RBD can act out their dreams by vocalising or moving their arms and legs. The disorder is linked to a failure of the normal mechanisms which keep the body still during dreams.

Some 80 patients with RBD and a control group of 90 others participated in the study.

The algorithm calculated the motion of pixels between consecutive frames of the video to detect movements during REM sleep.

The researchers then considered data on the rate, ratio, magnitude, and velocity of movements, as well as the ratio of immobility, when trying to detect the condition.

Study author Dr Emmanuel During, an associate professor of neurology and medicine at Mount Sinai School of Medicine in , said: “This automated approach could be integrated into clinical workflow during the interpretation of sleep tests to enhance and facilitate diagnosis, and avoid missed diagnoses.

“This method could also be used to inform treatment decisions based on the severity of movements displayed during the sleep tests and, ultimately, help doctors personalise care plans for individual patients.”