19th February 2024

A 78-year-old male has presented to the acute medical unit with falls, poor mobility and a shuffling gait.

A 78-year-old male has presented to the acute medical unit with falls, poor mobility and a shuffling gait. His speech has also become softer. On examination, he has a resting tremor along his left hand, which improves with activity. He also has global rigidity along all four limbs. He cannot rhythmically tap his foot or index finger with his thumb quickly.

Given the likely diagnosis, which area of the brain has been affected?