unilateral spatial neglect

Neglect is one of the strangest consequences of stroke. The person is not blind on one side, yet they behave as if half the world has quietly stopped existing. They eat only the food on the right half of the plate and leave the left untouched, shave only the right cheek, bump the wheelchair into door frames on the left, and may not turn toward someone speaking from their left — not because they cannot see or hear, but because their brain no longer pays attention to that side of space.

Neglect usually follows damage to the right side of the brain (which is dominant for attention to space), so the neglected side is the left. The eyes and ears work; what fails is the spotlight of attention. In severe cases it bleeds into the body and the imagination too — a person may deny that their own left arm is theirs, or, asked to imagine a familiar square, describe only the buildings that would be on their right. A particularly dangerous form is when the person is unaware they have any problem at all (a lack of insight), so they take risks confidently and do not understand why others are worried.

In rehabilitation neglect is a major safety and recovery barrier — it makes falls, collisions, and accidents far more likely, and it blocks the person from using a limb they have stopped attending to. Therapists work to draw attention back to the neglected side: cueing the person to scan left, placing important things on that side, anchoring tasks with bright markers, and using strategies that engage the neglected limb. The honest caveat is that neglect can be more disabling than the weakness itself, and that lack of awareness makes it stubborn — you cannot simply tell someone to 'remember the left' if their brain does not register that the left exists.