Little is known about the neural correlates of lower limbs position sense, despite the impact that proprioceptive deficits have on everyday life activities, such as posture and gait control. We used fMRI to investigate in 30 healthy right-handed and right-footed subjects the regional distribution of brain activity during position matching tasks performed with the right dominant and the left nondominant foot. Along with the brain activation, we assessed the performance during both ipsilateral and contralateral matching tasks. Subjects had lower errors when matching was performed by the left nondominant foot. The fMRI analysis suggested that the significant regions responsible for position sense are in the right parietal and frontal cortex, providing a first characterization of the neural correlates of foot position matching.

Using a computational approach to extract the spinal canal from whole-body PET/CT images, Marini et al. reveal increased glucose consumption in the spinal cord in prospectively recruited patients with amyotrophic lateral sclerosis. Simultaneous measurement of brain 18F-Fluorodeoxyglucose uptake reveals a divergent metabolic response in the two structures.

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