Neural correlates of somatosensory processing in patients with neglect

Abstract

Purpose: Recent evidence from neuroimaging studies using visual tasks suggests that the right superior parietal cortex plays a pivotal role for the recovery of neglect. Importantly, neglect-related deficits are not limited to the visual system and have a rather multimodal nature. We employed somatosensory stimulation in patients with neglect in order to analyze activity changes in networks that are presumably associated with this condition. Methods: Eleven chronic neglect patients with right hemispherical stroke were investigated with a fMRI paradigm in which the affected and unaffected hand were passively moved. Results: Brain activation was correlated with the performance in clinical neglect tests. Significant positive correlations with brain activation were found for the lesion duration, the performance in bells and letter cancellation tests and the line bisection test. These activated areas formed a distributed pattern in the right superior parietal cortex. Conclusions: The results suggest a shared representation of visual and somatosensory networks in the right superior parietal cortex in patients with right hemispherical strokes and neglect. The spatial pattern of activity in the superior parietal cortex points out to a different representation of changes related to lesion duration and neglect.