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Hemispatial Neglect (and Autosomatagnosia)
Published in Alexander R. Toftness, Incredible Consequences of Brain Injury, 2023
Hemispatial neglect can be broken down further into personal and extrapersonal neglect. Personal neglect refers to the person's own body, such that everything on the left side of their body does not exist as far as they are concerned. Instead, they neglect those body parts. They may forget to lace up their left shoe, incorrectly position their glasses on their left ear, and otherwise forget their left half (Baas et al., 2011). Some people may rarely or never use the arm or leg on their neglected side—although they may still use those limbs when pressured to do so (Sampanis & Riddoch, 2013). One way that personal neglect is tested for is by using a comb and razor test to see how the person grooms themselves—specifically, whether they ignore one side of their face and only comb and shave the other side (Beschin & Robertson, 1997). Personal neglect is closely related to the disorders of body imperception that are discussed a bit further on in this chapter.
Laterality Effects for Higher Cognitive Processes
Published in Robert Miller, Axonal Conduction Time and Human Cerebral Laterality, 2019
It is well known from the study of patients with unilateral cerebral injury that patients commonly suffer from “neglect” syndromes. Such “neglect” syndromes consist of a systematic failure to notice stimuli. A common test of neglect is “simultaneous bilateral” stimulation, when the patient fails to notice the stimulus contralateral to the injured (usually right) hemisphere (extinction). Often the neglect is multimodal, though more restricted forms of neglect have also been described in recent years (Halligan and Marshall, 1991; Tegner and Levander, 1991; Mennemeier et al., 1992; Liu et al., 1992; Binder et al., 1992; Guariglia and Antonucci, 1992; Guariglia et al., 1993; see review by Heilman and Valenstein, 1979). Most cases of neglect are hemispatial neglect, and this occurs with almost equal frequency for right and left hemisphere damage, usually from inferior parietal damage (Valler and Perani, 1987). However, the basis of such neglect is asymmetrical because neglect resulting from right hemisphere damage is far more severe and persistent than that resulting from left sided damage (e.g. Albert, 1973).
Non-invasive brain stimulation in Stroke patients (NIBS): A prospective randomized open blinded end-point (PROBE) feasibility trial using transcranial direct current stimulation (tDCS) in post-stroke hemispatial neglect
Published in Neuropsychological Rehabilitation, 2021
Gemma Learmonth, Christopher S.Y. Benwell, Gesine Märker, Diana Dascalu, Matthew Checketts, Celestine Santosh, Mark Barber, Matthew Walters, Keith W. Muir, Monika Harvey
Hemispatial neglect is a disorder resulting in an inability to respond to events in the left half of subjective space and up to 85% of patients with right hemisphere stroke can experience it acutely after stroke (see Stone et al., 1991 for overview). Recovery tends to be most rapid over the first 10 days (Stone et al., 1992) with some further improvement within 12–14 weeks, and neglect still present after this period in over 50% of cases (Nijboer et al., 2013). Manifestations include visual or sensory inattention and anosognosia (impaired awareness of the affected side), both of which impede participation in rehabilitation therapies. The presence of neglect is further associated with increased length of hospital stay (Nys et al., 2005), increased physical and occupational therapy requirements, and reduced likelihood of regaining independence (Kalra et al., 1997; Katz et al., 1999). Evidence for the benefit of any intervention for neglect is currently insufficient (Bowen et al., 2013; Ten Brink et al., 2017).
Post‐stroke visual midline shift syndrome
Published in Clinical and Experimental Optometry, 2020
Tammy Labreche, Benjamin Wild, Kristine Dalton, Susan J Leat
Hemispatial neglect is most common and severe following right brain damage as a result of infarctions in the middle cerebral artery insulting the posterior parietal cortex, and occurs less frequently, and tends to be less severe following left brain damage.2001 The dichotomies in incidence and severity of neglect between right and left brain damage are attributed to the asymmetric distribution of attention provided by the hemispheres. The right brain distributes attention to both the left and right hemispaces, while the left brain allocates attention mostly to the right hemispace.2011 Therefore, when the left brain is affected, the right brain can compensate for the loss and maintain attention across the whole space, but when the right brain is affected, attention in the left hemispace is lost.
Using real-time fMRI neurofeedback to restore right occipital cortex activity in patients with left visuo-spatial neglect: proof-of-principle and preliminary results
Published in Neuropsychological Rehabilitation, 2019
Fabien Robineau, Arnaud Saj, Rémi Neveu, Dimitri Van De Ville, Frank Scharnowski, Patrik Vuilleumier
Hemispatial neglect is among the most common and disabling disorders following focal brain damage, characterised by impaired awareness for the contralesional side of space (Driver & Vuilleumier, 2001; Milner and McIntosh, 2005; Vuilleumier and Saj, 2013). This syndrome typically results from lesions in frontal and parietal areas of the right hemisphere (Husain & Kennard, 1997; Mort et al., 2003) or their connections (Bartolomeo, de Schotten, & Doricchi, 2007; Karnath, Rorden, & Ticini, 2009), producing pathological biases in mechanisms of spatial attention controlled by these fronto-parietal networks, while primary sensory (e.g., visual) areas may remain structurally spared (Vuilleumier, 2013). Recent studies using functional brain imaging in patients with stroke and neglect have revealed that losses in awareness may reflect reduced neural responses in intact sensory areas due to a lack of top-down modulation from damaged brain regions and subsequent interhemispheric balance in fronto-parietal attentional networks (Valenza, Seghier, Schwartz, Lazeyras, & Vuilleumier, 2004; Corbetta, Kincade, Lewis, Snyder, & Sapir, 2005; Vuilleumier et al., 2008).