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: Surgery
[{'content': 'A middle aged female is having essential blepharospasm and is planned to be treated with Botulinum toxin. Which of the following is not true? \nSelect and explain. \nA. Need repeat injections, B. Diplopia may occur, C. Type C is most effective, D. Response rate is over 95%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Type C is most effective The initial treatment of choice in essential blepharospasm is Botulinum toxin type A. Among seven available form (A, B, C, D, E, F & G), only type A is used clinically and is most effective form. Botulinum toxin - Chemodenervation: * Type A is used * Block neuromuscular junctions (Cholinergic) * Onset 24-72 Hrs * Duration 3 months, hence need repeat injections * Dose: 1.25-5 unit/injection site. Usually given at 4 initial sites. * Response rate is 95-98%. * Adverse effects: Ptosis, Epiphora, Keratitis, dy eyes, diplopia', 'role': 'assistant'}]