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Stroke research suggests that at least one out of three and perhaps as many as eight out of ten people after stroke are unable to use an "internal GPS" to locate themselves within their environment (Buxbaum and colleagues, 2004; Stone and colleagues, 1998). The right hemisphere of the brain appears to store critical mapping information that allows us to make sense of the world around us, even if it is just our house or a familiar neighborhood. In a situation where we need to locate objects and move efficiently and adaptively in a complex environment -- for example, shopping in a busy supermarket -- this system helps us to identify relevant items rapidly, reach for them and avoid obstacles effortlessly, estimate how many groceries we can put in a bag to keep the weight manageable, and decide how we should place our groceries in our car to keep them stable.
When this system is damaged by a stroke, brain tumor, head injury or other focal brain disorder, a survivor can make spatial errors. Barrett and Burkholder (2006) define "spatial neglect" as a failure to report, respond or orient to the environment on the side opposite the individual's brain injury. Spatial neglect affects all aspects of ADL, rehabilitation potential and ultimately functional outcomes. Spatial neglect appears to be the strongest predictor of functional independence compared with any other stroke-related deficit, including hemiparesis and aphasia (Fullerton and colleagues, 1986). Debilitating loss of ADL is much more common in people with this disorder (Jehkonen and colleagues, 2006).
Although there are several ideas about what exactly causes this problem and how to categorize its symptoms, spatial neglect can manifest as one of two main issues. The first can be described as a "where" problem in responding to perceptual-attentional feedback. This may be more related to impairment in back of the brain, in temporal and parietal systems. The second type of difficulty is an "aiming" problem that interferes with the patient's appropriate initiation and self-direction of movement, and is feedback-independent. "Aiming" errors may reflect frontal lobe or subcortical brain dysfunction.
Visual inattention can be characterized with respect to the space affected: personal neglect, which affects one side of the body; peri-personal space, within reaching distance, and; extra-personal space, beyond reaching distance. An individual may have "where" and/or "aiming" symptoms of spatial neglect in one or all of these spatial regions. The problem can range from profound body unawareness on one side (asomatosagnosia, an inability to recognize a body part as their own) to mild neglect-related errors during unpredictable and multimodal functioning as would be evident during an activity such as driving.
Even mild spatial-neglect errors can be devastating to function and independence because a vast range of activities including working, financial management tasks and interpersonal interactions all depend critically on our ability to perceive and act effortlessly on our immediate environment.
Treatment Options
Historically, occupational therapists have treated spatial neglect using one of two behavioral approaches: restorative or adaptive. For patients who are aware of their neglect symptoms, a restorative approach would include activities that provide verbal/auditory/tactile/kinesthetic cuing to encourage the client to look to the unattended space. Interventions may include scanning in the extra-personal environment; reaching toward the "neglected side" to obtain objects (the therapist may need to physically guide the patient); anchoring; NDT, specifically weight shifting during sitting and/or standing and handling techniques; and constraint-induced movement therapy.
The adaptive approach utilizes a dynamic/interactional frame of reference in which the therapist asks the patient to identify ways to alter a given task to facilitate performance. Specific activities include visual scanning (head and eye movement compensation), lighthouse techniques, visual imagery and verbal cuing (e.g., "Look to left" every time a task begins).
These approaches are based on sensory-motor rehabilitation and didactic/learning theory, which are methods to teach healthy or developing brains to acquire skills. These approaches, then, may not optimize learning in a person with an impaired brain. They are also not easily translated to target "where" versus "aiming" problems.
Our team of clinicians and researchers at Kessler Institute for Rehabilitation in New Jersey developed a clinical care-clinical research partnership with the Kessler Foundation Research Center's (KFRC) Stroke Lab to identify and evaluate new interventions for stroke patients with spatial neglect.
Kimberly Hreha, OTR, has worked at Kessler Institute for Rehabilitation in West Orange, NJ, for four years and has been involved in research studies with the Kessler Foundation for the last two years. She is currently the public relations chair for the New Jersey Occupational Therapy Association. Monika Eller, OTR, is the Severe Disorders of Consciousness (SDOC) Program Manager at the Kessler West Orange campus. She has 25 years of experience in acute rehabilitation, and holds specialty certifications in NDT and the A-ONE assessment. Anna M. Barrett, MD, is a neurologist and clinician-researcher at the Kessler Foundation and is president-elect of the American Society of Neurorehabilitation. Her academic teaching, clinical practice and research program focus on "hidden disabilities" after stroke.
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