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: Unknown
[{'content': 'Which of the following is true regarding Horner&;s syndrome? (E. REPEAT 2008) \nSelect and explain. \nA. Constriction of pupil, B. Complete ptosis, C. Excessive sweating, D. Loss of accommodation', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ref: Basak's Essentials of Ophthalmology, 5th edition Explanation: HORNER'S SYNDROME Clinical Features Miosis. Partial ptosis. Enophthalmos. Loss of ciliospinal reflex (Unilateral absence of sweating). Congenital Horner's syndrome is associated with Heterochromia Iris. Path: Damage to sympathetic innervation of the eye. Etiology In the cervical region o Apical bronchial carcinoma o Ca of neck glands. Centrally o Multiple sclerosis o Pontine tumor o Syringomyelia. Pupillary light reflex and accommodation are normal. Dilation is affected. How to differentiate Pre and Postganglionic sympathetic lesions? If the lesion lies peripherally (Post-ganglionic), it dilates rapidly with 1 in 1000 adrenaline drops. This is due to Denervation super-sensitivity. Ptosis can be corrected for the cosmetic purpose by Mullerectomy.", 'role': 'assistant'}]