A 52-year-old man from rural Maharashtra presents with a 3-week history of progressive gait disturbance and difficulty with fine motor tasks. On examination, he has a wide-based gait, positive Romberg test, and dysmetria on finger-to-nose testing. MRI brain shows a large mass in the cerebellar hemisphere with compression of the fourth ventricle. Which of the following cerebellar connections is most likely disrupted, leading to his dysmetria?