Brain imaging in rem sleep behavior disorder

Abstract

REM sleep behavior disorder (RBD) is a parasomnia typically occurring during REM sleep, characterized by complex and often violent behaviors. More than 80% of idiopathic RBD (iRBD) eventually develop a neurodegenerative disease, mostly a synucleinopathy. Brain imaging techniques provide in vivo demonstration of structural and functional abnormalities in such patients. Several studies have shown that iRBD patients often exhibit brain imaging finding suggestive of incipient neurodegenerative process, even without clinical sign of parkinsonism or dementia. On the one hand, these findings are allowing a better understanding of the pathophysiological basis underlying RBD. Moreover, growing evidence are suggesting that the use of brain imaging may allow the identification of iRBD patients at high risk of short-term conversion in a definite neurodegenerative disorder. Neuroprotective therapies for synucleinopathies are not available yet, but the identification of patients to be included in neuroprotective clinical trials is a main research priority nowadays.