Recovery From Visual Neglect After Right Hemisphere Stroke: Does Starting Point in Cancellation Tasks Change After 6 Months?

Abstract

In the acute phase of stroke, patients with left visual neglect (VN) automatically orient to the right hemispace. This study examined the presence of rightward bias after right hemisphere stroke within 10 days of stroke onset and after 6 months. Our sample comprised 43 patients and 49 healthy controls. Presence of VN was evaluated with the six conventional subtests of the Behavioral Inattention Test (BITC). Starting points were determined in three BITC cancellation tasks by measuring the distance between the starting point and the median line of the stimulus sheet in centimeters. Activities of daily living (ADL) were assessed with the Barthel Index. At baseline VN patients showed more robust rightward bias than patients without VN. The magnitude of rightward bias decreased clearly in the VN patients at follow-up. A favorable ADL outcome was observed in 90% of the patients with VN and in all of the patients without VN. The magnitude of rightward bias differed clearly between the patient groups and controls. Our result implies that VN was likely to have improved as measured by BITC sum scores, but symptoms of rightward attention bias were still detected. We therefore suggest that, for clinical purposes, it is important that attention bias is measured accurately after right hemisphere stroke.Keywords: Rightward bias; Recovery; Stroke; Visual neglect. INTRODUCTIONVisual neglect (VN) is a disabling disorder that frequently occurs after right hemisphere stroke (Bowen, McKenna, & Tallis, 1999;Ringman, Saver, Woolson, Clarke, & Adams, 2004), suggesting a special role for the right hemisphere in spatial attention (Halligan, Fink, Marshall, & Vallar, 2003; Heilman, Watson, & Valenstein, 2003;Shulman et al., 2010). Neglect refers to failure to report, respond, or orient to stimuli on the contralesional side of space that cannot be accounted for by primary sensory or motor deficits (Halligan, Cockburn, & Wilson, 1991; Heilman et al., 2003;Robertson & Halligan, 1999). One prominent theory of this asymmetry in VN is that the left hemisphere controls shifts of attention in the rightward direction, while the right hemisphere controls shifts of attention in either direction (Mesulam, 1981). In the acute phase of stroke, patients with left visual neglect (VN) automatically orient to the right hemispace. This study examined the presence of rightward bias after right hemisphere stroke within 10 days of stroke onset and after 6 months. Our sample comprised 43 patients and 49 healthy controls. Presence of VN was evaluated with the six conventional subtests of the Behavioral Inattention Test (BITC). Starting points were determined in three BITC cancellation tasks by measuring the distance between the starting point and the median line of the stimulus sheet in centimeters. Activities of daily living (ADL) were assessed with the Barthel Index. At baseline VN patients showed more robust rightward bias than patients without VN. The magnitude of rightward bias decreased clearly in the VN patients at follow-up. A favorable ADL outcome was...

Occurrence and Recovery of Different Neglect-Related Symptoms in Right Hemisphere Infarct Patients during a 1-Year Follow-Up

“…These results support Karnath's (1988) suggestion that persisting ipsilateral orienting bias is one component of residual deficits in neglect patients who have recovered abilities of contralesional orienting. They also support previous findings that neglect patients may show ipsilateral orienting bias six to 12 months after stroke (Bonato, 2012;Kettunen et al, 2012;Mattingley et al, 1994;Samuelsson et al, 1996). However, only limited scientific attention has previously been devoted to the recovery of patients with initially milder inattention symptoms (i.e.…”

“…Bonato, 2012;Cassidy, Lewis, & Grey, 1998;Harvey & Gilchrist, 2002), although recovery may fluctuate during the first year (Jehkonen, Laihosalo, Koivisto, Dastidar, & Ahonen, 2007). Initial ipsilateral orienting bias, on the other hand, is often present for six to seven (Bonato, 2012;Kettunen et al, 2012;Samuelsson et al, 1996), even 12 months (Mattingley et al, 1994) after stroke, despite the recovered ability to reorient attention towards the contralesional side.…”

Ipsilesional Bias and Processing Speed are Important Predictors of Functional Dependency in the Neglect Phenomenon After a Right Hemisphere Stroke

“…It also merits attention that even though data about the overall stroke severity early after stroke were included in the stepwise regressions, ipsilesional bias (start column) and processing speed (time per identified letter) were identified as the relatively strongest predictors of dependency. Previous studies have highlighted the clinical importance of spontaneous rightward capture of attention in the neglect phenomenon (Azouvi et al, 2002(Azouvi et al, , 2006Gainotti et al, 1991Gainotti et al, , 2010Jalas et al, 2002;Karnath, 1988;Karnath & Rorden, 2012;Kettunen et al, 2012;Kinsbourne, 1993;Nurmi et al, 2010;Samuelsson et al, 1996) and of impairments in temporal processing capacity (Husain & Rorden, 2003;Husain et al, 1997;Robertson et al, 1998;Samuelsson, Hjelmquist, Jensen, Ekholm, & Blomstrand, 1998). The results of the current study suggest that the relative importance of right capture of attention and slow speed of visual processing are not only important symptoms of the VSN phenomenon per se, but that they also are important predictors of functional dependency.…”

“…It is well known that an ipsilesional bias in orientation of attention (i.e., an initial ipsilesional orientation of attention) is a fundamental component of VSN (Azouvi et al, 2002(Azouvi et al, , 2006Gainotti, 2010;Gainotti, D'Erme, & Bartolomeo, 1991;Jalas, Lindell, Brunila, Tenovuo, & Hamalainen, 2002;Karnath, 1988;Kettunen, Nurmi, Dastidar, & Jehkonen, 2012;Kinsbourne, 1993;Mattingley, Bradshaw, Bradshaw, & Nettleton, 1994;Nurmi et al, 2010;Samuelsson, Hjelmquist, Naver, & Blomstrand, 1996;Stone et al, 1991;Webster et al, 1995). It has also been considered that impaired speed in perceptual processing represents an additional core component of the neglect phenomena .…”

Component deficits of visual neglect: “Magnetic” attraction of attention vs. impaired spatial working memory

“…Of note, even after rehabilitation, patient P25's performance on paper and pencil tests with the presence of ipsilesional items was particularly impaired. This patient also showed perseverations on these tests, as well as a rightward starting point, which is one of the most sensitive markers of the presence (Azouvi et al, 2002) and persistence (Kettunen, Nurmi, Dastidar, & Jehkonen, 2012) of left neglect.…”