Early signs of Parkinson’s may already be visible during sleep

A sluggish day after a restless night: many people with Parkinson’s disease experience sleep problems. Remarkably, such symptoms occur long before the first visible ones. Neuroscientist Kaat Colman from the University of Antwerp (Faculty of Medicine and Health Sciences, UAntwerp) and Antwerp University Hospital (UZA) is investigating whether sleep can therefore serve as an early predictor of Parkinson’s.

 

Each year, 11 April is dedicated to Parkinson’s disease, the second most common neurodegenerative disorder worldwide. In these conditions, brain cells become damaged or die. In Belgium, an estimated 50 000 people are living with the condition. Although Parkinson’s is often associated with motor symptoms such as tremors and slowness, other signs appear much earlier, including a reduced sense of smell, memory problems and depressive symptoms.

One of the earliest possible warning signs is disrupted sleep. ‘REM sleep in particular plays a key role,’ says Kaat Colman, PhD researcher in translational neurosciences (UAntwerp/UZA). ‘This is the stage of sleep when we dream most vividly. In some patients, this sleep state is so dysregulated that they physically act out their dreams by kicking, hitting or shouting. This is referred to as REM sleep behaviour disorder.’

 

Sleep as a predictor

Strikingly, more than 90% of people with this disorder later develop Parkinson’s or a related condition. Sleep is therefore not only a symptom, but also a powerful predictor of the disease.

 

In her research, however, Colman aims to go one step further. ‘At the sleep centre of Antwerp University Hospital, we can measure extremely subtle disturbances in REM sleep: abnormalities that are far less pronounced than those seen in REM sleep behaviour disorder. Our goal is to determine whether these very slight changes can be linked to the very earliest stage of Parkinson’s.’

Preventing damage

‘If such a link exists, we may be able to detect the disease before noticeable symptoms or brain damage occur,’ Colman explains. ‘That is crucial, because Parkinson’s is often only diagnosed once brain damage has already ocurred. This damage is irreversible. If we can intervene earlier, we can treat the disease at a point where we can make the greatest impact.’