Hisakazu Uno1, Kazuyuki Nagatsuka2, Yoshihiro Kokubo3, Masahiro Higashi4, Naoaki Yamada4, Arisa Umesaki2, Kazunori Toyoda5, Hiroaki Naritomi2. 1. Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan; Department of Internal Medicine, Takarazuka Sanda Hospital, Sanda, Japan. Electronic address: hisaunotsh@leto.eonet.ne.jp. 2. Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan. 3. Department of Preventive Medicine and Epidemiologic Informatics, National Cerebral and Cardiovascular Center, Suita, Japan. 4. Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Japan. 5. Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan.
Abstract
BACKGROUND: Experimental studies of transient focal ischemia indicate biphasic detectability of lesions by diffusion-weighted imaging (DWI); poorly detectable phase exists at 1-12 hours after reperfusion. The present study aimed to clarify whether poorly detectable phase also exists in DWI of transient ischemic attack (TIA) patients. METHODS: A retrospective study was conducted in 144 consecutive TIA patients who underwent magnetic resonance imaging (MRI) within 2 weeks after carotid TIA. Patients were classified into 9 groups according to time from disappearance of TIA symptoms to DWI: intraischemic period, 0-1 hour, 1-12 hours, 12-24 hours, 1-2 days, 2-3 days, 3-7 days, 7-10 days, and 10-14 days after the end of TIA. RESULTS: Lesions were detected in 33 of 144 patients (22.9%). The frequency of positive lesions was 20% in the intraischemic period and 30.8% at 0-1 hour after the end of TIA; it markedly decreased to 8.7% at 1-12 hours after end of TIA. Thereafter, it increased to 21.7%, 30.8%, 36.4%, 37.0%, 38.5%, and 30% at 12-24 hours, 1-2 days, 2-3 days, 3-7 days, 7-10 days, and 10-14 days after the end of TIA, respectively. In 7 patients, MRI was repeated twice, at 1-12 hours and then at 5-13 days after the end of TIA. Lesions were never detected on the first MRI but were clearly demonstrated in 4 of 7 patients on the second MRI. CONCLUSIONS: The detectability of ischemic lesions may be biphasic after TIA as indicated by experimental studies.
BACKGROUND: Experimental studies of transient focal ischemia indicate biphasic detectability of lesions by diffusion-weighted imaging (DWI); poorly detectable phase exists at 1-12 hours after reperfusion. The present study aimed to clarify whether poorly detectable phase also exists in DWI of transient ischemic attack (TIA) patients. METHODS: A retrospective study was conducted in 144 consecutive TIA patients who underwent magnetic resonance imaging (MRI) within 2 weeks after carotid TIA. Patients were classified into 9 groups according to time from disappearance of TIA symptoms to DWI: intraischemic period, 0-1 hour, 1-12 hours, 12-24 hours, 1-2 days, 2-3 days, 3-7 days, 7-10 days, and 10-14 days after the end of TIA. RESULTS: Lesions were detected in 33 of 144 patients (22.9%). The frequency of positive lesions was 20% in the intraischemic period and 30.8% at 0-1 hour after the end of TIA; it markedly decreased to 8.7% at 1-12 hours after end of TIA. Thereafter, it increased to 21.7%, 30.8%, 36.4%, 37.0%, 38.5%, and 30% at 12-24 hours, 1-2 days, 2-3 days, 3-7 days, 7-10 days, and 10-14 days after the end of TIA, respectively. In 7 patients, MRI was repeated twice, at 1-12 hours and then at 5-13 days after the end of TIA. Lesions were never detected on the first MRI but were clearly demonstrated in 4 of 7 patients on the second MRI. CONCLUSIONS: The detectability of ischemic lesions may be biphasic after TIA as indicated by experimental studies.
Authors: Inger Havsteen; Christian Ovesen; Lasse Willer; Janus Damm Nybing; Karen Ægidius; Jacob Marstrand; Per Meden; Sverre Rosenbaum; Marie Norsker Folke; Hanne Christensen; Anders Christensen Journal: Front Neurol Date: 2017-12-18 Impact factor: 4.003