1H-MR Spectroscopy Changes in Transient Ischemic Attack Patients and Their Correlation with Perfusion-Weighted Imaging

Abstract

ABSTRACTPurpose: We investigated whether patients with transient ischemic attack (TIA) have metabolic changes in the brain. Methods: 35 patients with clinically diagnosed TIA were prospectively included in our study. Clinical and neurological data were compiled. 1H-MR spectroscopy and perfusion-weighted imaging were performed in all patients within 3 days of the onset of symptoms. Results: In TIA patients, the N-acetylaspartate (NAA)/choline (Cho) ratio in noninfarcted regions was significantly decreased in the symptomatic hemisphere (1.33 ± 0.38) compared with the asymptomatic hemisphere (1.51 ± 0.41, p < .05). Patients with a history of prior TIA had a significantly decreased NAA/Cho ratio in both the symptomatic (p < .05) and asymptomatic (p < .05) hemispheres compared with TIA patients without a prior TIA. TIA patients with diffusion-weighted imaging lesions had a significantly increased lactate/NAA ratio in both the symptomatic (p < .05) and asymptomatic (p < .05) hemispheres compared with TIA patients without lesions. The relative cerebral blood flow (rCBF) value was directly related to the symptomatic Cho/creatine (Cr) value (r = 0.81, p < .01). The higher the rCBF value, the higher the symptomatic Cho/Cr value. Conclusions: TIA patients have neurological deficits that are transient; however, metabolic damage to the brain is present up to 3 days after the onset of the symptoms. These metabolic changes are not restricted to the symptomatic hemisphere or to areas close to ischemic lesions and the changes are related in the CBF.