Left neglect, also known as unilateral neglect or hemispatial neglect, is one of the oddest symptoms of a brain injury. It can also be one of the most troublesome symptoms. Left neglect is a term describing a deficit in awareness that occurs following an injury to the right side of the brain. Due to the injury, the brain has difficulty paying attention to items falling into the left hemisphere of an individual’s awareness. This generally sees its clearest expression in difficulties with visually noticing items on the left side. For instance, a survivor with left neglect may bump into frames of doors on his or her left side or routinely miss eating food sitting on the left side of a plate. It often appears as if he or she is blind to items on the left, but this is not a true vision issue. It is an attention issue. The brain is not attending to information generated from the individual’s left side. The survivor can have perfect visual skills, but the message that the survivor’s brain is providing is that the left side of his or her world for all intents and purposes does not exist.
Left neglect does not only involve visual components, but can also manifest as a lack of attention to sound or touch on the left-hand side. For example, survivors may report that they cannot hear as well from their left ears despite audiological testing demonstrating perfect hearing. Survivors may fail to notice left hands getting stuck in the wheels of their wheelchairs, potentially injuring those hands. In the most severe of cases, survivors may not recognize their own left arms or legs as being parts of their bodies. They may find cause to ask something like, “Whose arm is this in my bed?” Fine variations in damage suffered to slightly different parts of the right side of the brain lead to notably distinct manifestations of left neglect, making each survivor’s experiences differ in some regard to that of the next.
Left neglect difficulties can cause many serious safety problems. For instance, a survivor may not notice a boiling pot of water sitting upon the stove on his or her left side and bump into that pot’s handle. This could then cause that pot to spill and lead to serious burns. Similarly, a survivor may not sufficiently attend to cars on his or her left and attempt to cross a busy street at an inopportune moment, risking being hit by a car. It is not uncommon for survivors with left neglect to have ever-present bruising on the left side of their bodies due to bumping into items. To make the issue even more complex, many survivors with left neglect may also have issues with impulse control or now be much more easily distracted. This then substantially compounds the danger and difficulties confronted by survivors contending with left neglect. Some survivors may also be outright missing vision on the left side (a condition known as a field cut), adding an actual visual problem on top of these attentional issues. Even when survivors are equipped with a complete awareness of their left neglect, in the absence of treatment the difficulties and errors unfortunately will still persist. Remember, the brain is unconsciously telling the survivors to ignore the left side. The neglect is not an intentional act by the survivors. Since the brain is creating this false message, the survivors feel like everything is normal and that they are attending to the left just as well as they would have prior to the injury.
Though left neglect is most certainly an issue of attention, it cannot be treated with stimulant medications like Ritalin (which can generally be relied upon to improve more typical attention deficits). The survivor must engage in specific therapies and learn compensatory techniques to help make more manageable these attentional deficits. Even with treatment, left neglect strategies must be practiced and carried over into life at home in order to avoid seeing a regression in a survivor’s performance.
Left neglect can affect a survivor’s ability to engage in activities requiring both tabletop scanning and environmental scanning. Examples of left neglect effects on tabletop tasks can be observed when survivors with left neglect miss words on the left side of a page or overlook numbers on the left side of a bill. Some examples of left neglect effects as related to environmental scanning would be survivors missing potholes on the left side of a street or failure to locate a car parked on the left side of a parking lot.
There are a number of methods to help survivors compensate for left neglect. One such method is known as prism adaptation. This is a method used by rehabilitation professionals in which patients engage in an activity while wearing strong prism glasses which pull visual items from the left into a more central attentional domain. This visual change forces the patients to compensate for the effects of the prism in order to accurately complete the activity. After the activity, some patients with left neglect notice an aftereffect in which the brain will continue to pull visual items from the left more into their attention even when the glasses are no longer being worn.
Limb activation therapy is another method used by professionals to aid with left neglect. The focus in this method is to get the patient to actively use his or her left limbs in the space surrounding the left side of his or her body in order to engage the brain’s spatial and motor maps for those domains. This has been found to be very helpful to patients, but unfortunately substantial difficulties are all too often encountered. As it’s common for survivors contending with left neglect to also have difficulty moving anything on the left side of their bodies (such targeted paralysis or semi-paralysis is itself one of the most common symptoms of a stroke or brain injury), the limits inherent in attempting to apply such a method become apparent. However, some research shows that even passive movement of the left side can help improve issues stemming from left neglect.
Working at honing scanning techniques is one of the most frequently utilized methods in treating patients with left neglect. Patients are taught by therapists methods by which to ensure that they have scanned the entire visual field. To do so, patients are often instructed to pretend as if the head is a lighthouse. Patients will be directed to turn their heads all of the way from one side to the other while scanning an environment just as a lighthouse will turn it’s light fully from one side to the other in order to effectively scan the seas. As a general rule of thumb, patients are taught that if they are scanning their environments and they have not seen their left shoulders, then they probably have not scanned as far to the left as needed. When involved in tabletop activities, patients are taught to scan to their left hands or left elbows. Practicing this type of scanning can be done in multiple ways. Patients may be asked to scan for and then identify letters or lights spread out upon a board or asked to scan and then find features in a parking lot. Often, therapists teach patients to highlight the left side of a page or place a bright bookmark next to the left side of a page so as to institute a cue to help recognize when they have scanned all the way to the left. If the patients have not seen the highlighted area or bookmark, then they know they have not made it as far to the left as they should. Patients are taught to always start their scanning from the left and then move slowly to the right. Patients with left neglect are less likely to miss items if they begin the scanning process on the left and proceed to the right than if they do the reverse.
Therapists may also deliberately place items on the left side of patients in order to force those patients to move, scan and utilize their left sides. A glass of water with dinner may be placed to the left of a plate. The therapist may pass a pen to the patient’s left hand. All of these seemingly small acts contribute to improving scanning to the left and to using the left side of the body in the left hemisphere of the space occupied by the patient. The ultimate goal is for robust scanning and increased use of the left side to become part of daily habit in the patients’ lives. Therapists also may use other cues to help a patient better attend to the left. For instance, they may put bells on a patient’s left hand so that he or she will hear the bells every time that left hand falls from the wheelchair (and then know to pick the hand back up).
Scanning skills can often be easily taught to family and friends, which can be of great help to the survivor in extending use of these techniques beyond an environment explicitly dedicated to therapy. Family and friends can also help by identifying situations in which the survivor may be having a difficulty related to left neglect of which he or she is not aware. All involved can then apply this knowledge so as to aid in identifying how left neglect could impact future situations. For example, a family member may help a survivor in an airport recognize that he or she has knocked over a fellow traveler’s bag and then also help the survivor prepare to enter the plane without bumping into the left aisle seats. This manner of aided behavior reinforced over time will do much to improve that survivor’s solo interactions with his or her world.
Hopefully this post has provided an amount of useful guidance on the road to a wider, more complete understanding of left neglect. Feel free to leave comments below with any questions!
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