Frédéric Assal

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Hysterical conversion disorders refer to functional neurological deficits such as paralysis, anaesthesia or blindness not caused by organic damage but associated with emotional "psychogenic" disturbances. Symptoms are not intentionally feigned by the patients whose handicap often outweighs possible short-term gains. Neural concomitants of their altered(More)
BACKGROUND Few studies have explored motor imagery (MI) as a way of accessing the higher-level of control of complex body movements involved in gait or balance. The objective of this study was 1) to measure and compare the time needed to complete the Timed Up & Go test (TUG), the time needed to imagine performing the same test (iTUG) and to calculate the(More)
The objective of this study was to systematically review all published articles examining the relationship between the occurrence of falls and changes in gait and attention-demanding task performance whilst dual tasking amongst older adults. An English and French Medline and Cochrane library search ranging from 1997 to 2008 indexed under 'accidental falls',(More)
OBJECTIVES Gait and cognitive disorders are frequently reported in patients with multiple sclerosis, leading to decreased quality of live. The objective of this prospective study was to examine the impact of four specific cognitive tasks on gait in patients with relapsing-remitting multiple sclerosis (RRMS) with low disability. METHODS The mean±standard(More)
BACKGROUND Gait disorders caused by dementia have been associated with frontal lobe dysfunction. Dual-tasking is used to explore the involvement of cortical level in gait control. It has been shown that dual-task induced gait changes that could be related to (1) the efficiency of executive function, (2) the level of difficulty involved in the(More)
BACKGROUND/AIMS To measure the Timed Up and Go (TUG), imagined TUG (iTUG), and the difference of time between these two tests (delta time) in 20 patients with relapsing-remitting multiple sclerosis (RRMS) and 20 healthy age-matched controls and to examine whether an association with cognitive functions, motor impairment, and behavioral changes can be(More)
The main diagnostic criteria of the behavioural variant of frontotemporal degeneration (bvFTD) include neurobehavioral and dysexecutive syndromes, but not specific gait characteristics although strong relationship between gait and prefrontal functions are increasingly recognized. Accordingly, we tested the hypothesis that patients with bvFTD would have more(More)
Alien hand syndrome is a rare neurological disorder in which movements are performed without conscious will. By using functional magnetic resonance imaging in a patient with alien hand syndrome after right parietal lesion, we could identify brain regions activated during involuntary or voluntary actions with the affected left hand. Alien hand movements(More)
BACKGROUND Serotonin has been linked to neuropsychiatric symptoms in Alzheimer disease, mainly agitation/aggression, depression, and psychosis. Neuropsychiatric symptoms have been associated with polymorphisms of the promoter region (5-HTTPR ) and intron 2 of the serotonin transporter gene (5-HTTVNTR) or the 5-HT2A and 5-HT2C receptor genes in some but not(More)
PURPOSE OF REVIEW Neuropsychiatric, or non-cognitive symptoms are increasingly recognized as manifestations of dementias. RECENT FINDINGS In Alzheimer's disease, recent advances have included the identification of behavioral profiles, differentiation of apathy and depression, characterization of risk factors for psychosis and its links to agitation and(More)