Cognitive and Neuropsychiatric Profiles in Idiopathic Rapid Eye Movement Sleep Behavior Disorder and Parkinson's Disease.

Francesca Assogna,Lucia Macchiusi,Claudia Belli,Mariangela Pierantozzi,Francesco E Pontieri,Alessandro Stefani,Fabio Placidi,Francesca Izzi,Bruno Mercuri,Claudio Liguori,Nicola B Mercuri,Luca Cravello,Clelia Pellicano,Carlo Caltagirone,Gianfranco Spalletta

doi:10.3390/jpm11010051

Abstract

Rapid eye movement (REM) sleep behavior disorder (RBD) is a risk factor for developing Parkinson’s disease (PD) and may represent its prodromal state. We compared neuropsychological and neuropsychiatric phenotypes of idiopathic (i) RBD, PD and healthy comparators (HC) in order to identify iRBD specific characteristics. Thirty-eight patients with iRBD, 38 PD patients with RBD (PD + RBD), 38 PD patients without RBD (PD-RBD) and 38 HC underwent a comprehensive neurological, neuropsychological and neuropsychiatric evaluation. iRBD, PD + RBD and PD-RBD performed worse than HC in short-term verbal memory, praxia, language and executive functions. iRBD had higher levels of anxiety, depression, apathy and alexithymia than HC. iRBD had higher levels of apathy than PD + RBD. Both PD groups had higher levels of anxiety and depression than HC. Surprisingly, iRBD performed better than all groups in long-term verbal memory. Patients diagnosed with iRBD are characterized by poor global cognitive performance, but better long-term memory and higher levels of depression, anxiety, alexithymia and apathy. Alexithymia and apathy in patients diagnosed with iRBD may be the expression of precocious derangement of emotional regulation, subsequently observed also in PD. Cognitive and neuropsychiatric symptoms of iRBD are early clinical manifestations of widespread neurodegeneration.

Highlights

Rapid Eye Movement (REM) sleep Behavior Disorder (RBD) is a parasomnia characterized by loss of normal skeletal muscle atonia during Rapid eye movement (REM) sleep, such that patients “act out” dreams, often violently, which is potentially harmful for themselves and their bedpartner [1]
We found a significantly higher score in the UPDRS-III in the two groups of patients diagnosed with Parkinson’s disease (PD) compared to idiopathic form of RBD (iRBD)
No significant differences were found in illness duration, daily levodopa equivalent dosage and H&Y stage between the two groups diagnosed with PD (Table 1)

Summary

Introduction

Rapid Eye Movement (REM) sleep Behavior Disorder (RBD) is a parasomnia characterized by loss of normal skeletal muscle atonia during REM sleep, such that patients “act out” dreams, often violently, which is potentially harmful for themselves and their bedpartner [1]. The idiopathic form of RBD (iRBD) generally affects male adults [2]. The prevalence of RBD reaches about 15–60% in patients with PD [4], whereas the prevalence of iRBD is less than 1% in the general population [5]. RBD and PD share some pathophysiological mechanisms, such as neuronal loss and α-synuclein degeneration in brainstem nuclei modulating REM sleep atonia, in locus coeruleus-subcoeruleus complex, in the raphe nucleus, substantia nigra and common neuroinflammation markers [7]

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Results