Contribution of the superior colliculi to post-stroke unilateral spatial neglect and recovery

Unilateral spatial neglect (USN) is a highly prevalent and disabling consequence of stroke that often responds poorly to existing interventions. Its underlying neural mechanisms are still unclear. Recent work suggests that post-stroke USN may be partly related to a disruption of top-down and bottom-up control of visual attention mediated in part through the midbrain superior colliculi (SC). With mounting evidence from animal and human research, our objectives were: (1) to synthesize the literature implicating the SC in USN; (2) to review the rationale and potential for using eye patching and prism adaptation as USN treatment approaches that recruit SC involvement; and (3) to provide recommendations for research on the potential of therapeutic interventions that involve and/or target the retino-collicular pathway. Given the paucity of human studies, the contribution of the SC in USN, while plausible, remains to be confirmed. Further exploration of the mechanisms involved and their impact on USN in human subjects will help develop theoretically based intervention strategies tailored to USN type.