Anatomical Correlates of Directional Hypokinesia in Patients with Hemispatial Neglect

Sapir, Ayelet; Kaplan, Julie B; He, Biyu J.; Corbetta, Maurizio

doi:10.1523/jneurosci.0041-07.2007

Cited by 68 publications

(56 citation statements)

References 40 publications

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“…In particular, there were no criteria for a directional hypokinesia, a condition characterized by the inability to execute movements even with the unaffected arm in or toward the contralesional hemispace in patients with hemineglect (Coslett et al, 1990;Sapir et al, 2007). Indeed, the tapping task performed by the right and left hands in both ipsilateral and contralateral hemispaces was no different between the right and left hemispaces.…”

Section: Discussionmentioning

confidence: 99%

Posterior SMA Syndrome following subcortical stroke: Contralateral akinesia reversed by visual feedback

et al. 2013

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Background: The supplementary motor area (SMA) plays a key role in motor programming and production and is involved in internally-cued movements. In neurological populations, SMA syndrome following a lesion to the "SMA proper" is characterized by transient impairment of voluntary movements and motor sequences. This syndrome is assumed to follow on from an interruption of the motor corticosubcortical loop, and some case reports indicate that such a syndrome could occur after a brain lesion isolating the SMA from subcortical structures. Aim: To characterize the pattern of motor impairments in a patient whose stroke disconnects the SMA from the subcortical motor loop. Method: A patient developed a moderate transient left hemiparesis following a subcortical stroke in the right anterior cerebral artery area, which disconnected the SMA from basal ganglia. Eight days after the stroke, when the hemiparesis had regressed, the patient presented a specific SMA motor disorder of the left hand which manifested as an akinesia and was exacerbated when his visual attention was not directed towards his hand. We assessed finger tapping with left and right hands, eyes closed and open, in the left and right hemispace. We indexed movement speed as the number of taps filmed over 5-s periods.Results: Left motor weakness (grasping strength of right hand: 49 kg and left hand: 41 kg) was resolved in a week. Ideomotor and ideational gestures and motor sequences were preserved. On the tapping task, left-hand tapping was slower than right-hand tapping. Critically, visual feedback improved tapping speed for the left, but not for the right, hand. The hemispace of the task execution had no effect on tapping performance. Conclusion: Our results suggest that SMA-basal ganglia disconnection decreases contralateral movement initiation and maintenance and this effect is partly compensated by visual cues.

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Section: Discussionmentioning

confidence: 99%

Posterior SMA Syndrome following subcortical stroke: Contralateral akinesia reversed by visual feedback

et al. 2013

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“…Recently, a few studies have used voxel-wise lesion-symptom mapping to probe the neural correlates of neglect (Karnath, Rennig, Johannsen, & Rorden, 2011; Molenberghs, Gillebert, Peeters, & Vandenberghe, 2008; Ptak & Schnider, 2011; Rengachary et al, 2011; Saj et al, 2012; Sapir, Kaplan, He, & Corbetta, 2007) and of its different cognitive components (Verdon, Schwartz, Lovblad, Hauert, & Vuilleumier, 2010). …”

Section: Discussionmentioning

confidence: 99%

Differential white matter involvement associated with distinct visuospatial deficits after right hemisphere stroke

Carter

McAvoy

Siegel

et al. 2017

Cortex

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Visuospatial attention depends on the integration of multiple processes, and people with right hemisphere lesions after a stroke may exhibit severe or no visuospatial deficits. The anatomy of core components of visuospatial attention is an area of intense interest. Here we examine the relationship between the disruption of core components of attention and lesion distribution in a heterogeneous group (N=70) of patients with right hemisphere strokes regardless of the presence of clinical neglect. Deficits of lateralized spatial orienting, measured as the difference in reaction times for responding to visual targets in the contralesional or ipsilesional visual field, and deficits in re-orienting attention, as measured by the difference in reaction times for invalidly vs. validly cued targets, were measured using a computerized spatial orienting task. Both measures were related through logistic regression and a novel ridge regression method to anatomical damage measured with magnetic resonance imaging. While many regions were common to both deficit maps, a deficit in lateralized spatial orienting was more associated with lesions in the white matter underlying the posterior parietal cortex, and middle and inferior frontal gyri. A deficit in re-orienting of attention toward unattended locations was associated with lesions in the white matter of the posterior parietal cortex, insular cortex and less so with white matter involvement of the anterior frontal lobe. An hodological analysis also supports this partial dissociation between the white matter tracts that are damaged in lateralized spatial biases versus impaired re-orienting. Our results underscore that the integrity of fronto-parietal white matter tracts is crucial for visuospatial attention and that different attention components are mediated by partially distinct neuronal substrates.

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“…Given that spatial attention and SWM involve largely overlapping brain networks it is not surprising that lesions to right fronto-parietal regions, in addition to leading to neglect, are also likely to cause deficits in SWM (e.g. Vallar and Perani, 1986; Mattingley et al, 1998; Karnath et al, 2001; Mort et al, 2003; Sapir et al, 2007). …”

Section: Spatial Working Memorymentioning

confidence: 99%

Spatial Working Memory Deficits Represent a Core Challenge for Rehabilitating Neglect

Striemer¹,

Ferber²,

Danckert³

2013

Front. Hum. Neurosci.

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Left neglect following right hemisphere injury is a debilitating disorder that has proven extremely difficult to rehabilitate. Traditional models of neglect have focused on impaired spatial attention as the core deficit and as such, most rehabilitation methods have tried to improve attentional processes. However, many of these techniques (e.g., visual scanning training, caloric stimulation, neck muscle vibration) produce only short-lived effects, or are too uncomfortable to use as a routine treatment. More recently, many investigators have begun examining the beneficial effects of prism adaptation for the treatment of neglect. Although prism adaptation has been shown to have some beneficial effects on both overt and covert spatial attention, it does not reliably alter many of the perceptual biases evident in neglect. One of the challenges of neglect rehabilitation may lie in the heterogeneous nature of the deficits. Most notably, a number of researchers have shown that neglect patients present with severe deficits in spatial working memory (SWM) in addition to their attentional impairments. Given that SWM can be seen as a foundational cognitive mechanism, critical for a wide range of other functions, any deficit in SWM memory will undoubtedly have severe consequences. In the current review we examine the evidence for SWM deficits in neglect and propose that it constitutes a core component of the syndrome. We present preliminary data which suggest that at least one current rehabilitation method (prism adaptation) has no effect on SWM deficits in neglect. Finally, we end by reviewing recent work that examines the effectiveness of SWM training and how SWM training may prove to be a useful avenue for future rehabilitative efforts in patients with neglect.

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Anatomical Correlates of Directional Hypokinesia in Patients with Hemispatial Neglect

Cited by 68 publications

References 40 publications

Posterior SMA Syndrome following subcortical stroke: Contralateral akinesia reversed by visual feedback

Posterior SMA Syndrome following subcortical stroke: Contralateral akinesia reversed by visual feedback

Differential white matter involvement associated with distinct visuospatial deficits after right hemisphere stroke

Spatial Working Memory Deficits Represent a Core Challenge for Rehabilitating Neglect

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