A 62-year-old man presents to the emergency department with sudden-onset dizziness and vomiting. On exam, he has left-sided ptosis and miosis. He also has decreased pain and temperature sensation on the left side of his face and on the right side of his body. His gait is wide-based, and finger-to-nose testing shows dysmetria on the left. Which additional neurologic deficit is most consistent with the affected brainstem region based on the “Rules of 4” concept?

(Assume the lesion is in the brainstem and localizes to the lateral region.)