Striatal Dopaminergic Deficit and Sleep in Idiopathic Rapid Eye Movement Behaviour Disorder: An Explorative Study

Area of Science:

• Neurology
• Sleep Medicine
• Neuroimaging

Background:

• Idiopathic REM sleep behavior disorder (iRBD) is a precursor to alpha-synucleinopathies.
• iRBD involves dream enactment, loss of muscle atonia, and increased REM sleep muscle activity.
• Early sleep dysfunction in iRBD may indicate caudate dysfunction.

Purpose of the Study:

• To investigate the relationship between early sleep changes and striatal dopaminergic availability in iRBD.
• To explore correlations between specific sleep parameters and dopamine transporter (DaT) uptake in iRBD patients.

Main Methods:

• Retrospective analysis of 12 iRBD patients and 22 matched controls.
• Video polysomnography and striatal dopamine transporter (DaT) imaging were used.
• Statistical analysis identified altered sleep parameters and correlated them with DaT signaling.

Main Results:

• iRBD patients showed more periodic limb movements during sleep than controls.
• Sleep fragmentation was strongly associated with dopamine deficiency in the left caudate.
• Increased striatal DaT uptake correlated with better sleep efficiency and duration.

Conclusions:

• This study demonstrates a link between striatal dopaminergic availability and sleep quality in iRBD.
• Exploratory findings suggest early striatal changes in iRBD impact sleep architecture.
• These findings highlight potential early biomarkers for alpha-synucleinopathies.