Jean-François Gagnon

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OBJECTIVE To determine the frequency of REM sleep behavior disorder (RBD) among patients with PD using both history and polysomnography (PSG) recordings and to further study REM sleep muscle atonia in PD. BACKGROUND The reported occurrence of RBD in PD varies from 15 to 47%. However, no study has estimated the frequency of RBD using PSG recordings or(More)
OBJECTIVE Idiopathic REM sleep behavior disorder (RBD) is a potential preclinical marker for the development of neurodegenerative diseases, particularly Parkinson disease (PD) and Lewy body dementia. However, the long-term risk of developing neurodegeneration in patients with idiopathic RBD has not been established. Obtaining an accurate picture of this(More)
Rapid-eye-movement (REM) sleep behaviour disorder (RBD) is characterised by loss of muscular atonia and prominent motor behaviours during REM sleep. RBD can cause sleep disruption and severe injuries for the patient or bed partner. The disorder is strongly associated with neurodegenerative diseases, such as multiple-system atrophy, Parkinson's disease,(More)
Idiopathic rapid eye movement sleep behaviour disorder is an important risk factor in the development of Parkinson's disease. Numerous potential predictive markers of Parkinson's disease may present before motor symptoms emerge, but testing of these markers in rapid eye movement sleep behaviour disorder has been performed only in small studies. There has(More)
OBJECTIVE To investigate the frequency and subtypes of mild cognitive impairment (MCI) in idiopathic rapid eye movement sleep behavior disorder (RBD) and Parkinson's disease (PD) in association with RBD. METHODS One hundred and twelve subjects without dementia or major depression including 32 idiopathic RBD patients, 22 PD patients with(More)
REM sleep behavior disorder is a unique parasomnia characterized by dream enactment behavior during REM sleep. Unless triggered by pharmacologic agents such as antidepressants, it is generally related to damage of pontomedullary brainstem structures. Idiopathic REM sleep behavior disorder (RBD) is a well-established risk factor for neurodegenerative(More)
OBJECTIVE For development of neuroprotective therapy, neurodegenerative disease must be identified as early as possible. However, current means of identifying "preclinical" neurodegeneration are limited. Patients with idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) are at >50% risk of synuclein-mediated neurodegenerative disease--this(More)
Previous anatomical volumetric studies have shown that healthy aging is associated with gray matter tissue loss in specific cerebral regions. However, these studies may have potentially missed critical elements of age-related brain changes, which largely exist within interrelationships among brain regions. This magnetic resonance imaging research aims to(More)
Parkinsonism, as a gradually progressive disorder, has a prodromal interval during which neurodegeneration has begun but cardinal manifestations have not fully developed. A systematic direct assessment of this interval has never been performed. Since patients with idiopathic REM sleep behaviour disorder are at very high risk of parkinsonism, they provide a(More)
Sports-related concussions have been shown to lead to persistent subclinical anomalies of the motor and cognitive systems in young asymptomatic athletes. In advancing age, these latent alterations correlate with detectable motor and cognitive function decline. Until now, the interacting effects of concussions and the normal ageing process on white matter(More)