Diagnostic value of repeated ice tests in the evaluation of ptosis in myasthenia gravis

Abstract

Twenty-six patients with ptosis related to Myasthenia gravis (MG) and 38 controls with ptosis other than MG were included. All patients were tested with the ice test 2 times on separate days in the afternoon. The margin reflex distance (MRD) was measured before and immediately after 2-minute application of ice on the eyelids. The ice test was judged positive if there was an improvement of at least 2.0 mm of MRD after the ice test. Among the patients with negative test results, 'equivocal’ was defined by improvement of MRD from at least 1.0 mm to less than 2.0 mm after the ice test. Repeated ice test results showed an agreement of 61.5% in MG, and 97.4% in nonmyasthenic ptosis. Repeated ice tests increased the sensitivity by 34.6% compared to a single test. Among the patients with repeatedly negative test results, 63.6% of those who showed equivocal results at least once turned out to be MG. Of those with repeated non-equivocal negative results, nobody turned out to be MG. There was no significant difference of the ice test results between ocular MG and generalized MG (p = 0.562).

Diagnostic yields and clinical features of ocular myasthenia gravis

“…As in previous reports, the ice test is a simple, specific, and relatively sensitive test for the diagnosis of myasthenic ptosis. [ 5 , 6 , 20 ] In addition, Cogan's lid twitch is reported to have a sensitivity of up to 75% and a specificity approaching 99% in MG with ptosis. [ 21 ] The Cogan's lid twitch, in which the ptotic lid briefly elevates excessively after a vertical saccade from a downgaze position.…”

Evaluating the temperature effects of ice and heat tests on ptosis due to Myasthenia Gravis

“…While the reliability of the ice test has been confirmed by several studies [5][6][7][16][17][18][19], values for sensitivity and specificity have varied widely. A recent study suggested the ice test has a sensitivity of only 38.5% after a single test, and repeated tests on the same patient giving the same results 61.5% of the time [20]. However, the study noted that the ice test maintained a very high specificity (97.4%) and positive predictive value (90.9%) even after a single application, and that a second application of the test increased its sensitivity to 73.1% [20].…”

“…A recent study suggested the ice test has a sensitivity of only 38.5% after a single test, and repeated tests on the same patient giving the same results 61.5% of the time [20]. However, the study noted that the ice test maintained a very high specificity (97.4%) and positive predictive value (90.9%) even after a single application, and that a second application of the test increased its sensitivity to 73.1% [20]. This suggests that an initial negative ice pack test should ideally be followed by a second application of the test at a later time.…”

Challenges in diagnosing coexisting ocular myasthenia gravis and thyroid eye disease

“…The ice pack test has been demonstrated to be helpful in supporting a diagnosis of OMG in patients with coexisting TED 45,84 . The ice pack test can also help discriminate ptosis due to MG from other causes including TED 85 …”