Article

Cardinal motor features of Parkinson's disease (PD) appear when about half of the
nigral dopamine neurons have disappeared. Based on extrapolations from
post-mortem and imaging studies, the delay between the onset of dopamine
denervation and the appearance of motor signs ranges from 5 to 20years. According
to Braak and co-workers, motor symptoms only appear at stage III of PD, while the
neurodegenerative process begins earlier in the olfactory bulb and lower brain
stem. In addition to the cardinal motor features, non-motor signs are
increasingly being recognized in PD. Some of them, mainly olfactory disturbances,
rapid-eye-movement sleep behaviour disorder and autonomic dysfunction, are
already present in the early disease stages and may precede the onset of motor
signs by up to four decades. These non-motor signs are related to widespread
extranigral and even extracerebral degeneration, and have been considered risk
factors for many years. Indeed, recent evidence suggests that they may be
prodromal manifestations of PD. From the perspective of future disease-modifying
or neuroprotective treatments, combining prodromal non-motor signs and
paraclinical investigations may help to further develop reliable tools for early
diagnosis of PD before the onset of its cardinal motor features.
CI - Copyright (c) 2012. Published by Elsevier Masson SAS.

Langue : ANGLAIS