This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
Propranolol is useful in all, Except 
Select and explain. 
A. Migrane, B. Thyrotoxicosis, C. Parkinsonian tremor, D. Oesophageal varices
C: Parkinsonian tremor
Answer: C: Parkinsonian tremor 
Explanation: Propranolol is used for essential tremor but not in parkinsonian tremor. In Graves disease, Propranolol (20-40 mg every 6 h) or longer-acting selective b1 receptor blockers such as atenolol may be helpful to control adrenergic symptoms, especially in the early stages before antithyroid drugs take effect. Beta blockers are also useful in patients with thyrotoxic periodic paralysis, pending correction of thyrotoxicosis. Propranolol reduces the frequency and intensity of a migraine headache. Beta-receptor antagonists have been found to diminish poal vein pressure in patients with cirrhosis. There is evidence that both propranolol and nadolol decrease the incidence of the first episode of bleeding from oesophagal varices Ref: Katzung 13e pg: 164-165