Final answer:
The nurse should anticipate the brain tumor being in the frontal lobe, which is responsible for cognitive functions, motor skills, and personality.
Step-by-step explanation:
Based on the symptoms of personality changes and difficulty with voluntary activities, the nurse should anticipate the brain tumor being located in the frontal lobe. The frontal lobe is known for its role in controlling cognitive functions such as maintaining attention, speech, decision-making, and also contains the motor cortex important for movement. Damages to this area can lead to personality changes, socialization issues, and altered risk assessment capacities. The frontal lobe also encompasses functions related to planning and executing movements, with different muscle groups being mapped within the motor cortex, controlling movements as detailed as those of the fingers and hand.