The ice test for diagnosing myasthenia gravis

There are many tests for diagnosis of myasthenia gravis including Tensilon test and ice test. To compare the ice test with Tensilon test in subjects with myasthenic and nonmyasthenic ptosis a process research study was designed. This study was performed in patients complaining of acquired ptosis in the neuro-ophthalmology center of Farabi Hospital. All 156 patients were tested with ice pack and edrophonium with an interval of 15 minutes. The patient was instructed to hold an ice filled plastic glove on the closed ptotic eyelid. Before and after 2 minutes of ice application on the ptotic eyelid, the distance between the upper and lower margin was measured by the neuro-ophthalmologist. An increase of 2 mm or higher was considered a positive test result. Patients with positive Tensilon test were considered as control. In all 61 patients with positive Tensilon test the ice test was positive, and in none of the 95 patients with negative Tensilon test the ice test was positive. The ice test is a simple, fast, specific and sensitive test for the diagnosis of myasthenic ptosis.