After suffering a stroke, which lobe of the brain is likely affected if a patient cannot move their right arm?

The left frontal lobe is responsible for controlling the movements of the right side of the body due to the crossing of motor pathways in the brain. When a stroke occurs in the left frontal lobe, it can disrupt the signals that are sent to the right arm, resulting in loss of motor function or paralysis on that side. This is because the left hemisphere of the brain governs motor function for the right side of the body. Thus, a patient who is unable to move their right arm after a stroke likely has an injury in the left frontal lobe.