This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
[{'content': 'Eye examination of a patient revealed lack of upward gaze and dilated pupils fixed to light. What is the MOST probable location of the lesion? \nSelect and explain. \nA. Optic chiasm, B. Inferior colliculus, C. Superior colliculus, D. Edinger Westphal nucleus', 'role': 'user'}, {'content': "Answer: C \nExplanation: In a patient with lesion of the superior colliculus, there is loss of upward gaze associated with dilated pupils that are fixed to light. Lesions in the collicular region is caused by pressure and distoion of underlying structures in the midbrain and not by damaged to specific pathways traversing the colliculi. It can produce any combination of impaired upward gaze, impaired downward gaze, pupillary abnormalities or loss accommodation reflex can occur. The general name for the clinical picture produced is called Perinaud's syndrome. Ref: Textbook of Ophthalmology edited by Sunita Agarwal, page 284.", 'role': 'assistant'}]