19th July 2023

A 65-year-old woman presents with loss of sensation on her right side and feeling unsteady

A 65-year-old woman presents with loss of sensation on her right side and feeling unsteady. On examination, you confirm a right arm and leg sensory loss. You also find she has loss of sensation on the left side of her face, with a left-sided ptosis and constricted pupil. She also has an ataxic gait.

Where is the most likely site of the lesion?

Select the SINGLE most appropriate option from the list below. Select ONE option only.