Brain Network Dysfunction in Poststroke Delirium and Spatial Neglect: An fMRI Study.

BACKGROUND AND PURPOSE: Delirium, an acute reduction in cognitive functioning, hinders stroke recovery and contributes to cognitive decline. Right-hemisphere stroke is linked with higher delirium incidence, likely, due to the prevalence of spatial neglect (SN), a right-brain disorder of spatial processing. This study tested if symptoms of delirium and SN after right-hemisphere stroke are associated with abnormal function of the right-dominant neural networks specialized for maintaining attention, orientation, and arousal. METHODS: Twenty-nine participants with right-hemisphere ischemic stroke undergoing acute rehabilitation completed delirium and SN assessments and functional neuroimaging scans. Whole-brain functional connectivity of 4 right-hemisphere seed regions in the cortical-subcortical arousal and attention networks was assessed for its relationship to validated SN and delirium severity measures. RESULTS: Of 29 patients, 6 (21%) met the diagnostic criteria for delirium and 16 (55%) for SN. Decreased connectivity of the right basal forebrain to brain stem and basal ganglia predicted more severe SN. Increased connectivity of the arousal and attention network regions with the parietal, frontal, and temporal structures in the unaffected hemisphere was also found in more severe delirium and SN. CONCLUSIONS: Delirium and SN are associated with decreased arousal network activity and an imbalance of cortico-subcortical hemispheric connectivity. Better understanding of neural correlates of poststroke delirium and SN will lead to improved neuroscience-based treatment development for these disorders. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03349411.

Illustrating where spatial perception versus memory-based representation: spatial neglect in a distinguished artist; a case report.

Spatial neglect is a disorder of attention, perception, and processing of stimuli in contralesional space. The heterogeneous behaviors involve diverse neuroanatomical mechanisms. Anecdotal evidence suggests that neural circuitry of active spatial perception may differ from that used to encode spatial memory. These differences can escape detection by conventional assessments, thereby leading to missed diagnoses. We present a case, in an artist who demonstrates selective impairment in a contralesional space during active Where spatial perception. His performance is better when asked to draw entirely from memory. This case highlights the variability in neglect, importance for comprehensive testing, and encourages further investigation.

Impact of spatial neglect on stroke rehabilitation: evidence from the setting of an inpatient rehabilitation facility.

OBJECTIVE: To examine the impact of spatial neglect on rehabilitation outcome, risk of falls, and discharge disposition in stroke survivors. DESIGN: Inception cohort. SETTING: Inpatient rehabilitation facility (IRF). PARTICIPANTS: Individuals with unilateral brain damage after their first stroke (N=108) were assessed at IRF admission and discharge. At admission, 74 of them (68.5%) demonstrated symptoms of spatial neglect as measured using the Kessler Foundation Neglect Assessment Process (KF-NAP). INTERVENTIONS: Usual and standard IRF care. MAIN OUTCOME MEASURES: The FIM, Conley Scale, number of falls, length of stay (LOS), and discharge disposition. RESULTS: The greater the severity of spatial neglect (higher KF-NAP scores) at IRF admission and the lower the FIM scores at admission as well as at discharge. Higher KF-NAP scores also correlated with greater LOS and lower FIM improvement rate. The presence of spatial neglect (KF-NAP score>0), but not Conley Scale scores, predicted falls such that participants with spatial neglect fell 6.5 times more often than those without symptoms. More severe neglect, indicated by KF-NAP scores at IRF admission, reduced the likelihood of returning home at discharge. A model that took spatial neglect and other demographic, socioeconomic, and clinical factors into account predicted home discharge. Rapid FIM improvement during IRF stay and lower annual income level were significant predictors of home discharge. CONCLUSIONS: Spatial neglect after a stroke is a prevalent problem and may negatively affect rehabilitation outcome, risk of falls, and LOS.