<prompt> Ice pack test is done for?Myasthenia GravisMultiple system atrophyHyperparathyroidismHypokalemic periodic paralysis  <response>: Ice pack test: In patients suspected of palpebral ptosis andor ophthalmoparesis due to myasthenia gravis. Investigations for the remaining choices mentioned in the question Disease Features Multiple system atrophy MRI showing hot cross buns sign and putaminal atrophy Hyperparathyroidism PTH assay and Technetium Peechnetate Scan. Hypokalemic periodic paralysis C.M.A.P compound muscle action potential shows low amplitude and shows no improvement in exercise. 