Transient aphasia: a rare complication of head-up tilt test

Head-up tilt test (HUT) is widely used as a diagnostic tool. It reproduces vasovagal attacks in many susceptible patients. Although it is known to be safe and well tolerated, it is a procedure with potential neurologic complications. We observed that it could cause transient aphasia in some patients. To explore clinical characteristics and possible pathogenesis of aphasia induced by HUT, we reviewed the data of patients undergoing HUT in our hospital. 13 patients experienced transient aphasia in 3,488 cases. According to the hemodynamic changes, the incidence in vasodepressor, mixed, cardioinhibition and the negative response were 6.67, 5.52, 0 and 1.14 ‰ orderly, and not significantly different among the groups. It had significant difference between the positive response and the negative response and between vasodepressor and the negative response (both p < 0.05). The incidence in adults was significantly higher than that in children (<18 years) (p < 0.01), but not different between female and male. The average onset time was 11.33 ± 6.66 min (range 4-17 min) during baseline HUT or 4.90 ± 2.69 min (range 2-10 min) during sublingual nitroglycerin-provocated HUT. The duration was 3-60 min, except for one who was completely relieved of the disorder 4 h later. In conclusions, there is a risk of provoking transient aphasia during HUT. It reminds that performer should alert the possibility of transient aphasia during the test, especially when the patient is an adult and has a positive response.