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...few documented contributions toward this responsibility. Although UN is complex problem that requires attention from several specialties, there is room for nurses to substantially increase their role. Nurses are uniquely positioned to assess and treat UN by virtue of their interaction with patients in a variety of times, settings, and activities. Nurses need to develop quantifiable measures of clinical observation that are reliable and valid in nursing practice. This article reviews the literature to examine the impact of UN, existing assessment methods, and nursing involvement in assessment and treatment. Potential nursing contributions in practice and research are featured as well.
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Unilateral neglect (UN) is a disorder that causes people with brain damage to behave as though one half of their world--the half contralateral to the damage--has become unimportant or simply ceased to exist (Mesulam, 2000). It is a striking disorder; while those affected may not orient to or interact with their contralesional environment or the contralesional half of their own bodies, this is not primarily caused by a sensory or motor deficit (Heilman, Watson, & Valenstein, 2002). So while homonymous hemianopia, hemianesthesia, hemiparesis, or other sensory and motor impairments may occur with UN, they do not cause UN and can be doubly disassociated from it. As clarified by Mesulam (2000), UN is "not a disorder of seeing, hearing, or moving, but one of looking, detecting, listening, and exploring" (p. 195).
A typical clinical picture of UN is a patient with damage to the right parietal cortex who slouches to the left; fixates head and eye orientation to the right; only dresses, grooms, or protects the right side of the body; ignores people on the left; eats food from only the right side of the plate; and frequently collides with leftward obstacles (Parton, Malhotra, & Husain, 2004; Robertson & Halligan, 1999). Although UN can occur after damage to either cerebral hemisphere, it appears to be more common, severe, and permanent after right-brain damage (Bowen, McKenna, & Tallis, 1999; Ringman, Saver, Woolson, Clarke, & Adams, 2004). There are several potential reasons for this. The right hemisphere appears to pay attention to both sides of space, while the left hemisphere focuses more exclusively on the contralateral half (Mesulam, 2002). The right hemisphere also appears specialized for global attention and the left hemisphere for focal attention (Kleinman et al., 2007). In addition, the right hemisphere may be more involved in sustained attention than the left (Robertson & Halligan).
UN's Functional Impact
UN may functionally affect as many as 200,000 stroke survivors in the United States (Barrett, Levy, & Gonzalez Rothi, 2007). UN frequently goes unacknowledged even though its consequences may be dramatic.
As measured by the Barthel index of activities of daily living (ADLs), UN has a more negative effect on functional ability after a stroke than age, sex, power, side of stroke, balance, proprioception, cognition, or premorbid ADL status (Kalra, Perez, Gupta, & Wittink, 1997). Its presence within the first 10 days of a stroke is a stronger predictor of poor functional recovery after i year than other variables including hemiparesis, hemianopia, age, visual memory, verbal memory, or visuoconstructional ability (Jehkonen et al., 2000). UN most likely is one of the reasons patients with right-hemisphere brain damage are twice as likely to fall as those with left-brain damage (Ugur, Gucuyener, Uzuner, Ozkan, & Ozdemir, 2000). Patients with UN require a longer rehabilitation period and make less daily progress than other patients with similar functional status (Gillen, Tennen, & McKee, 2005). Patients with UN also are less likely to live independently than patients who have both aphasia and right hemiparesis (Heilman et al., 2002).
UN Varieties
UN is a heterogeneous syndrome with several subtypes, and it is possible that many distinct disorders have been inaccurately lumped together under a single label (Halligan & Marshall, 1994; Stone, Halligan, Marshall, & Greenwood, 1998). There is growing consensus that no single mechanism accounts for the full range of UN signs and symptoms (Buxbaum, 2005). It appears that impairments of several different pathways converge to produce UN; interestingly, each of these impairments can exist independently without causing UN (Parton et al., 2004). Despite considerable effort, it has proven difficult to assign any particular variations of UN to specific neuroanatomical loci (Buxbaum). Despite these taxonomical limitations, UN may be loosely described with four overlapping variables: type, space, axis, and orientation.
Type
UN is broadly divided into disorders of either input or output (Bailey, Riddoch, & Crome, 2000). The neglect of input, often called inattention, includes ignoring contralesional auditory, visual, tactile, and even olfactory stimuli. Surprisingly, this inattention can apply to imagined stimuli. In what is termed representational or imaginal neglect, patients ignore the left side of memories, dreams, or hallucinations (Robertson & Halligan, 1999).
The neglect of output includes motor and premotor neglect (Robertson & Halligan, 1999). A patient with motor neglect does not use a contralesional limb despite the neuromuscular ability to do so. A person with premotor neglect, frequently termed directional hypokinesia, can move unaffected...
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