Time since stroke influences the impact of hemianopia and spatial neglect on visual-spatial tasks.

OBJECTIVE

Spatial neglect results in an ipsilesional misorientation of attention in visual-spatial tasks. Hemianopia impairs visual perception but its influence on visual-spatial tasks is subject to debate. Here, we investigated the influence of the time since stroke on the respective impacts of hemianopia and spatial neglect.

METHOD: A total of 29 patients with a right hemisphere stroke were included in the study. Nine had severe neglect and hemianopia, six had severe neglect only, four showed hemianopia with little or no neglect after infarction of the posterior cerebral artery, and 10 had neither neglect nor hemianopia. We investigated the spatial bias in the subjective straight ahead (SSA) test and in clinical tests (bell cancellation, line bisection, and scene copy). Each task was administered twice (at S1 and S2: 41.4 and 67.2 days [on average] after the stroke, respectively).

RESULTS

At S1, spatial neglect and hemianopia had an additive influence on SSA test performance (rightward translation). Similar rightward biases were observed in the clinical tests. At S2, the influence of hemianopia had disappeared, whereas that of neglect was still present. Furthermore, loss of bias in the SSA test correlated with the improvements seen in most of the clinical tests.

CONCLUSIONS

In patients with recent stroke, hemianopia aggravates the visual-spatial bias when neglect is present or may lead to visual-neglect-like behavior when classically defined neglect is absent. However, the influence of hemianopia disappears relatively quickly over time, due to compensation.