Correlation between somatosensory function and cortical activation induced by touch stimulation in patients with intracerebral hemorrhage

Abstract

Objectives: The correlation between somatosensory function and cortical activation induced by touch stimulation in patients with intracerebral hemorrhage (ICH) was investigated by functional magnetic resonance imaging (fMRI). Methods: Thirty-two chronic ICH patients with somatosensory deficits in tactile sensation were enrolled. For fMRI, touch stimulation was applied on the dorsum of the affected hand (contralateral to the ICH), using a rubber brush at a frequency of 1 Hz. Regions of interests (ROIs) were set at the primary sensory–motor cortex [SM1: Brodmann's area (BA) 1, 2, 3, 4], the posterior parietal cortex (PPC: BA 5, 7) and the secondary somatosensory cortex (S2: BA 43) in both hemispheres. The tactile sensation subscale of the Nottingham Sensory Assessment (NSA) was used to determine somatosensory function. Results: Significant correlations were found between NSA scores and voxel counts in the contralateral (ipsilesional) SM1 (r = 0.642; p < 0.05), the contralateral PPC (r = 0.507; p < 0.05) and the ipsilateral (contralesional) SM1 (r = 0.466; p < 0.05). However, no correlation was found between NSA scores and the contralateral S2 (r = 0.323; p > 0.05), the ipsilateral PPC (r = 0.252; p > 0.05) or the ipsilateral S2 (r = 0.280; p > 0.05). Conclusions: It was found that somatosensory functions were positively correlated with degrees of blood oxygenation level dependent signal change of the following ROIs: the contralateral SM1, the contralateral PPC and the ipsilateral SM1. Opposingly, the S2 showed no correlation on either side of the brain.