Left egocentric neglect in early subacute right-stroke patients is related to damage of the superior longitudinal fasciculus

Abstract

A typical consequence of stroke in the right hemisphere is unilateral spatial neglect. Distinct forms of neglect have been described, such as space-based (egocentric) and object-based (allocentric) neglect. However, the relationship between these two forms of neglect is still far from being understood, as well as their neural substrates. Here, we further explore this issue by using voxel lesion symptoms mapping (VLSM) analyses on a large sample of early subacute right-stroke patients assessed with the Apples Cancellation Test. This is a sensitive test that simultaneously measures both egocentric and allocentric neglect. Behaviourally, we found no correlation between egocentric and allocentric performance, indicating independent mechanisms supporting the two forms of neglect. This was confirmed by the VLSM analysis that pointed out a link between a damage in the superior longitudinal fasciculus and left egocentric neglect. By contrast, no association was found between brain damage and left allocentric neglect. These results indicate a higher probability to observe egocentric neglect as a consequence of white matter damages in the superior longitudinal fasciculus, while allocentric neglect appears more “globally” related to the whole lesion map. Overall, these findings on early subacute right-stroke patients highlight the role played by white matter integrity in sustaining attention-related operations within an egocentric frame of reference.

Non‐invasive Brain Stimulation Can Reduce Unilateral Spatial Neglect after Stroke: ELETRON Trial

“…Moreover, biomarkers and neuroimaging tests are needed to understand the plasticity mechanisms in USN patients to help select the best candidates for neuromodulation interventions. Some authors reported that lesions in the superior longitudinal fasciculus might cause persistent USN, and the evaluation by diffusion tensor imaging studies can provide direct evidence of anatomical localization of brain function for a better response after brain stimulation 34–36 . However, no biomarkers have been validated in stroke patients with USN.…”

“…Some authors reported that lesions in the superior longitudinal fasciculus might cause persistent USN, and the evaluation by diffusion tensor imaging studies can provide direct evidence of anatomical localization of brain function for a better response after brain stimulation. [34][35][36] However, no biomarkers have been validated in stroke patients with USN. Therefore, future efforts should compare optimal intervention strategies according to individual characteristics before larger and more comprehensive trials can be planned.…”

White matter tracts involved in subcortical unilateral spatial neglect in subacute stroke

“…The superior longitudinal fasciculus links the frontal cortex with the temporal, parietal, and occipital lobes and plays a major role in language, attention, memory, and emotions (44). Previous studies have demonstrated that damage to the superior longitudinal fasciculus is consistently found in patients with USN following stroke (15,16,45). Moreover, different loci of the involved superior longitudinal fasciculus were suggested to have a role in diverse USN phenotypes (46).…”

Detection of Stroke-Induced Visual Neglect and Target Response Prediction Using Augmented Reality and Electroencephalography

“…white matter attention networks, specifically in the frontalparietal superior longitudinal fasciculus, and some association with interhemispheric disconnections as well [2]- [5]. Some research has also correlated lesions in the ventral frontal lobe, right inferior parietal lobe or superior temporal lobe to the manifestation of SN [6], [7].…”