A study has indicated that REM sleep behaviour disorder is a risk factor for Parkinson's disease.
Patients suffering REM sleep behaviour disorders dream nightmares in which they are attacked and pursued, with the particularity that they express them by screaming, crying, punching and kicking while sleeping.
The new study applied brain SPECT to conclude that the levels of dopamine in the brain are quickly lowering over the years in patients with REM sleep behaviour disorder. This neuroimaging technique became the first tool to detect the disease progression at an early stage.
The study involved comparing for three years the evolution of brain SPECT in 20 patients with REM disorder and 20 healthy controls. The neuroimaging technique measures the presence of dopamine in the substantia nigra, a part of the brain associated with learning and harmony of body movements.
In Parkinson's disease a deficiency of dopamine in the substantia nigra causes tremor, stiffness and movement slowness in patients. Results show that after 3 years of monitoring the production of dopamine in the control group was reduced by 8 pc due to age, while the group of REM sleep disorder patients experienced a reduction of 20 pc. Once the 3 year follow-up ended, 3 of 20 patients in the REM sleep disorder group had developed Parkinson's disease and their dopamine reduction was around 30 pc.
The study is detailed in Lancet Neurology.