Ice pack test in the diagnosis of myasthenia gravis.

PURPOSE To demonstrate the sensitivity and the specificity of the ice test in the differential diagnosis of ptosis in myasthenia gravis. METHODS Prospective trial with a control group. The patients were instructed to hold a frozen ice pack on the closed ptotic eyelid. They were divided into 2 groups, with group I consisting of patients with myasthenia gravis and group II (control) consisting of patients with congenital, non-myasthenic myogenic or aponeurotic ptosis. RESULTS All patients in group I had increased palpebral fissure for at least 3 mm after the application of ice pack. No patient in group II showed increased palpebral fissure after the ice test. CONCLUSION Ice test proved to be specific for the detection of myasthenic ptosis.