A 58-year-old man from Delhi presents to the emergency department with acute onset of right-sided weakness affecting his face, arm, and leg equally. On examination, he has right facial droop, right-sided hemiparesis (3/5 power), hyperreflexia on the right side, and an extensor plantar response on the right. Speech is slurred. CT head shows a hyperdense lesion in the left basal ganglia region. Which anatomical structure has been damaged to produce this constellation of motor findings?