Clinical Application of Diffusion Tensor Imaging in Diagnosis and Prognosis of Hemifacial Spasm.

Abstract

The purpose of this study was to test the application of diffusion tensor imaging (DTI) in patients with hemifacial spasm (HFS), to make more accurate diagnoses before surgery and to judge the degree of recovery more accurately after surgical microvascular decompression. To our knowledge, this is the first study to test the validity of DTI for diagnosis and postsurgical evaluation of HFS. We included 40 patients with HFS who underwent DTI scanning before microvascular decompression. They were followed up with DTI 6 months and 1 year after surgery. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were obtained and compared. In patients with HFS, the FA value of the affected side (mean FA, 0.46 ± 0.03) was significantly lower than that of the healthy side (mean FA, 0.43 ± 0.04; P < 0.05), and the ADC value of the affected side (mean FA, 1.60 ± 0.14) was significantly higher than that of the healthy side (mean ADC, 1.50 ± 0.12; P < 0.05). Compared with those before surgery, the FA values of both follow-up patients increased significantly, whereas their ADC values decreased significantly. The use of DTI improves diagnosis and treatment of HFS.