A study published in PLoS One demonstrates no apparent association between the clinical severity of stroke within the first 2 weeks of the event and lost awareness for contralesional or ipsilesional stimuli, as measured on the letter cancellation test (LCT), which assesses the presence and severity of visuospatial neglect (VSN). In addition, large strokes tend to show a greater negative effect on visual attention recovery at the nonhemiplegic side compared with smaller strokes, the researchers reported.
For the analysis, study investigators obtained data from 2 prospective cohort studies composed of patients with first-ever ischemic right-hemisphere stroke and VSN (n=90). A total of 8 longitudinal, weekly measurements were performed after stroke onset (1, 2, 3, 4, 5, 8, 12, and 26 weeks). The primary outcome measure, which was obtained at each weekly measurement, was the LCT for assessing VSN presence and severity.
As part of the LCT, participants were required to cancel the letter “O” in addition to other letters on paper with 20 Os on the left and 20 Os on the right side, with 425 distractors on the sheet in total. In addition, the Bamford classification was used to measure the clinical severity of stroke, which differentiates between total anterior circulation infarct, partial anterior circulation infarct, lacunar anterior circulation infarct, and posterior circulation infarct.
Study researchers observed no association between patients’ clinical stroke severity and the number of contralesional (P =.23) and ipsilesional (P =.37) omissions on the LCT. There was a time-dependent association between the recovery of the VSN at both the contralesional hemiplegic and ipsilesional nonhemiplegic side in first-time stroke patients. For ipsilesional VSN, ipsilesional omissions tended to decrease each week, with 0.14 during the first 26 weeks. For contralesional VSN, the number of omissions decreased, with 0.31 at each week and follow-up assessment.
The lack of measures for lesion size and location, as well as the strict inclusion of only right-hemisphere first-time stroke, represents 2 limitations of this study.
The investigators explain that “it might be that the largest, most significant interaction effects between, on the one hand, severity of stroke, and, on the other hand, severity of VSN are found in the acute phase post stroke.”
Nijboer TCW, Winters C, Kollen BJ, Kwakkel G. Impact of clinical severity of stroke on the severity and recovery of visuospatial neglect [published online July 2, 2018]. PLoS One. doi: 10.1371/journal.pone.0198755