Associating Functional Neural Connectivity and Specific Aspects of Sensorimotor Control in Chronic Stroke

Abstract

Hand sensorimotor deficits often result from stroke, limiting the ability to perform daily living activities. Sensorimotor deficits are heterogeneous among stroke survivors. Previous work suggests a cause of hand deficits is altered neural connectivity. However, the relationships between neural connectivity and specific aspects of sensorimotor control have seldom been explored. Understanding these relationships is important for developing personalized rehabilitation strategies to improve individual patients’ specific sensorimotor deficits and, thus, rehabilitation outcomes. Here, we investigated the hypothesis that specific aspects of sensorimotor control will be associated with distinct neural connectivity in chronic stroke survivors. Twelve chronic stroke survivors performed a paretic hand grip-and-relax task while EEG was collected. Four aspects of hand sensorimotor grip control were extracted, including reaction time, relaxation time, force magnitude control, and force direction control. EEG source connectivity in the bilateral sensorimotor regions was calculated in α and β frequency bands during grip preparation and execution. Each of the four hand grip measures was significantly associated with a distinct connectivity measure. These results support further investigations into functional neural connectivity signatures that explain various aspects of sensorimotor control, to assist the development of personalized rehabilitation that targets the specific brain networks responsible for the individuals’ distinct sensorimotor deficits.

Cortical Sensorimotor Integration as a Neural Origin of Impaired Grip Force Direction Control following Stroke

“…We surmise that impaired performance in grip force direction control in the hand affected by a stroke may be manifested as a result of impaired cortical sensorimotor integration. We postulate that the performance may be facilitated by utilizing the residual neural resources including the sensorimotor network in the non-lesioned hemisphere as suggested by the previous studies [ 56 , 57 ].…”

“…The results of this study also expand the findings of previous research investigating the neural correlates of the grip force direction control following stroke. Previous studies have examined the connectivity of the brain’s neural circuits as associated with the grip force direction control following stroke [ 56 , 57 ]. For example, one study used diffusion tensor imaging (DTI) to assess the structural connectivity of the cortical and subcortical areas of the brain in 22 chronic stroke survivors [ 57 ].…”

“…This study found that poor grip force direction control was associated with lower structural connectivity in the network involving the bilateral Rolandic, ipsilesional supplementary motor area and contralesional thalamus [ 57 ]. Another study used a different approach using electroencephalography (EEG) in 12 chronic stroke survivors [ 56 ]. They found that poor grip force direction control was associated with lower functional neural connectivity between the contralesional premotor and primary somatosensory cortices [ 56 ].…”

“…Another study used a different approach using electroencephalography (EEG) in 12 chronic stroke survivors [ 56 ]. They found that poor grip force direction control was associated with lower functional neural connectivity between the contralesional premotor and primary somatosensory cortices [ 56 ].…”