Grant: Travel Awards - Institute Community Support

After a stroke, changes in the brain's functional connectivity (FC; communication between areas of the brain that are not anatomically near each other) are observed. It is possible that these changes disrupt recovery of motor patterns after a lesion to the brain from a stroke. Post-stroke FC changes play an important role in the development of impairment and may be a useful tool to predict the level of neurological impairment. In this study, we investigated whether changes in the interhemispheric resting-state FC (RS-FC) of the primary motor cortex after a stroke correlated with the patients' level of physical impairment. Post-stroke patients with at least of 3 months of recovery and age-matched control subjects underwent resting state functional magnetic resonance imaging (RS-fMRI). In this scan, patients and participants are asked to lay away with eyes open while images are taken. Areas of the brain with similar neural activity at rest were identified. The symmetry of this connectivity at rest was evaluated and correlated to the patient's level of physical impairment in order to assess whether the brain's connectivity at rest could be related to the physical deficiency. Analysis of patients' brain post-stroke indicated an asymmetrical pattern of connectivity between each side of the brain at rest. The side of the brain with the damage due to the stroke affected the amount the primary motor cortex that was connected between sides of the brain. A significant positive correlation between the pattern of connectivity of the hemisphere with the stroke lesions and the level of physical impairment indicated that subjects with more symmetric interhemispheric FC showed less neurological deficit. These results indicate that after a stroke there is a disruption in the functional connectivity of the brain's sensorimotor areas at rest. Additionally, this asymmetrical pattern of resting connectivity between motor areas may be a useful marker to predict physical impairment.