Impaired automatic and unconscious motor processes in Parkinson's disease.

While it is increasingly recognized that voluntary movements are produced by an interaction between conscious and unconscious processes, the role of the latter in Parkinson's disease has received little attention to date. Here, we administered a subliminal masked prime task to 15 Parkinson's disease patients and 15 age-matched healthy elderly subjects. Compatibility effects were examined by manipulating the direction of the arrows and the interstimuli interval.

Finger tapping clinimetric score prediction in Parkinson's disease using low-cost accelerometers.

The motor clinical hallmarks of Parkinson's disease (PD) are usually quantified by physicians using validated clinimetric scales such as the Unified Parkinson's Disease Rating Scale (MDS-UPDRS). However, clinical ratings are prone to subjectivity and inter-rater variability. The PD medical community is therefore looking for a simple, inexpensive, and objective rating method.

Role of the supplementary motor area in the automatic activation of motor plans in de novo Parkinson's disease patients.

The role of the basal ganglia-cortical motor loop in automatic and unconscious motor processes is poorly understood. Here, we used event-related functional magnetic resonance imaging in 11 de novo Parkinson's disease patients as they performed a visuomotor masked priming task. The stronger subliminal priming effect for the non-dominant side of motor symptoms than for the dominant side was paralleled by stronger supplementary motor area proper activity in response to lateralized visual stimuli presented below the threshold of awareness.

Brain activation pattern related to gait disturbances in Parkinson's disease.

Gait disturbances represent a therapeutic challenge in Parkinson's disease (PD). To further investigate their underlying pathophysiological mechanisms, we compared brain activation related to mental imagery of gait between 15 PD patients and 15 age-matched controls using a block-design functional MRI experiment. On average, patients showed altered locomotion relatively to controls, as assessed with a standardized gait test that evaluated the severity of PD-related gait disturbances on a 25-m path.

Construction and validation of the Dynamic Parkinson Gait Scale (DYPAGS).

The dynamic evaluation of Parkinson's disease (PD)-related episodic gait disturbances in routine is challenging. Therefore, the aim of our study was to assess the reliability/validity of the Dynamic Parkinson Gait Scale (DYPAGS) composed of eight relevant items for the objective quantification of PD gait features: walking forwards/backwards/with dual-task, turning to both sides, imaginary obstacle avoidance with both legs and passing through narrow spaces. The scale was validated on thirty-five patients with mild to severe parkinsonism in their habitual "on-state".

Gait feature extraction in Parkinson's disease using low-cost accelerometers.

The clinical hallmarks of Parkinson's disease (PD) are movement poverty and slowness (i.e. bradykinesia), muscle rigidity, limb tremor or gait disturbances.

Effects of light deprivation on visual evoked potentials in migraine without aura.

Background: The mechanisms underlying the interictal habituation deficit of cortical visual evoked potentials (VEP) in migraine are not well understood. Abnormal long-term functional plasticity of the visual cortex may play a role and it can be assessed experimentally by light deprivation (LD).

Methods: We have compared the effects of LD on VEP in migraine patients without aura between attacks (MO, n = 17) and in healthy volunteers (HV, n = 17).

Hemispheric specialization during mental imagery of brisk walking.

Objectives: Brisk walking, a sensitive test to evaluate gait capacity in normal and pathological aging such as parkinsonism, is used as an alternative to classical fitness program for motor rehabilitation and may help to decrease the risk of cognitive deterioration observed with aging. In this study, we aimed to identify brain areas normally involved in its control.

Methods: We conducted a block-design blood oxygen level dependent function magnetic resonance imaging (BOLD fMRI) experiment in 18 young healthy individuals trained to imagine themselves in three main situations: brisk walking in a 25-m-long corridor, standing or lying.