19th February 2024

A 67-year-old male with known diabetes and hypertension presents to the acute medical unit with weakness affecting his upper and lower limbs.

A 67-year-old male with known diabetes and hypertension presents to the acute medical unit with weakness affecting his upper and lower limbs. His sensory exam was normal. He also noted reduced vision in his right eye and double vision. He had reduced power along his left side with associated rigidity on examination. Gait ataxia was also noted. His right eye is at the inferotemporal position at rest. Right-sided ptosis and dilated pupil were noted. 

An ischaemic stroke was found to be the cause of his symptoms.

Which of the following regions of the brain has likely been affected?