Lee Seung-Koo, Mori Susumu, Kim Dong Joon, Kim Sei Young, Kim Si Yeon, Chu Minkyung, Heo Kyoung, Lee Byung In, Kim Dong Ik
Department of Radiology, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-752, Korea.
Epilepsia. 2003 Dec;44(12):1536-40. doi: 10.1111/j.0013-9580.2003.43502.x.
The usefulness of diffusion tensor magnetic resonance imaging (DT-MRI) is still in debate, and the development of clinically feasible scan protocol is encouraged. The purpose of this study was to investigate the afferent fiber system to the cerebellum in patients with phenytoin (PHT)-induced cerebellar atrophy in comparison with cerebellar atrophy of other etiologies by using DT-MRI.
Thirteen patients (M/F ratio, 7:6; mean age, 42.5 years) and age-matched normal controls (n = 8) participated in this study. The patient group consisted of epilepsy patients who had received PHT therapy (n = 9) and clinically diagnosed as having olivopontocerebellar atrophy (OPCA; n = 4). DT-MRI was performed by using diffusion weighting of b = 600 s/mm2, and fractional anisotropy (FA) and color-coded vector maps were generated. FA of the middle cerebellar peduncle (MCP), the cerebellum, and transverse pontine fibers (TPF) was measured and compared between PHT and OPCA patients.
Normal subjects showed FA values of 0.81 +/- 0.07 in MCP, 0.69 +/- 0.04 in TPF, and PHT users showed FA values of 0.84 +/- 0.09 in MCP, 0.72 +/- 0.08 in TPF, and 0.21 +/- 0.04 in cerebellum. OPCA patients showed FA values of 0.39 +/- 0.11 in MCP, 0.46 +/- 0.12 in TPF, and 0.22 +/- 0.07 in cerebellum. PHT users showed a statistically significant reduction of FA only in cerebellum, whereas OPCA demonstrated significant decrease of FA in MCP, TPF, and cerebellum (one-way analysis of variance, p < 0.01). Three-dimensional reconstruction of fiber tracts demonstrated decreased volume and altered fiber integrity within the peduncles and transverse pontine fibers in the OPCA group, whereas fiber course patterns in PHT users were similar to those in controls.
PHT users showed normal orientation and anisotropy of MCP and TPF, whereas OPCA demonstrated impaired values, suggesting that PHT directly affects the cerebellum. DT-MRI can demonstrate detailed fiber configurations in degenerative diseases of brainstem and cerebellum and provides insight into the pathomechanisms of cerebellar atrophy.
扩散张量磁共振成像（DT-MRI）的实用性仍存在争议，因此鼓励开发临床可行的扫描方案。本研究的目的是通过DT-MRI研究苯妥英（PHT）诱导的小脑萎缩患者与其他病因引起的小脑萎缩患者相比，传入小脑的纤维系统情况。
13例患者（男/女比例为7:6；平均年龄42.5岁）和年龄匹配的正常对照者（n = 8）参与了本研究。患者组包括接受PHT治疗的癫痫患者（n = 9）和临床诊断为橄榄脑桥小脑萎缩（OPCA；n = 4）的患者。使用b = 600 s/mm2的扩散加权进行DT-MRI检查，并生成分数各向异性（FA）和彩色编码矢量图。测量并比较PHT患者和OPCA患者小脑中脚（MCP）、小脑和脑桥横纤维（TPF）的FA值。
正常受试者MCP的FA值为0.81±0.07，TPF的FA值为0.69±0.04，使用PHT的患者MCP的FA值为0.84±0.09，TPF的FA值为0.72±0.08，小脑的FA值为0.21±0.04。OPCA患者MCP的FA值为0.39±0.11，TPF的FA值为0.46±0.12，小脑的FA值为0.22±0.07。使用PHT的患者仅在小脑中FA有统计学意义的降低，而OPCA在MCP、TPF和小脑中FA均显著降低（单因素方差分析，p < 0.01）。纤维束的三维重建显示OPCA组中脚和脑桥横纤维的体积减小且纤维完整性改变，而使用PHT的患者的纤维走行模式与对照组相似。
使用PHT的患者MCP和TPF的方向和各向异性正常，而OPCA显示值受损，提示PHT直接影响小脑。DT-MRI可以显示脑干和小脑退行性疾病中的详细纤维结构，并深入了解小脑萎缩的发病机制。
