共同性斜视患者视皮层的血氧水平依赖性功能磁共振成像特征

A BOLD-fMRI study on cortex activation intensity in comitant strabismus

目的 观察共同性斜视患者接受不同视差的立体图刺激下大脑皮层激活区域,比较共同性斜视患者与正常人的兴奋体素差异.方法 系列病例研究.选取共同性斜视患者12例为斜视组,平均年龄（16.9±3.9）岁;立体视觉正常者10例为正常组,平均年龄（21.2±2.7）岁.对研究对象行组块设计的血氧水平依赖性功能磁共振成像研究,刺激任务为非交叉视差的随机点立体图,分别为1 200″、2 400″、3 600″,静止状态为白底黑色“＋”号,采用SPM5软件及t检验对数据进行预处理及分析.结果 在视差1 200″刺激下,正常组显示右侧枕下回和左侧枕中回（BA18）激活,共同性斜视组激活区域显示左侧枕中回（BA18）激活;在视差2400″刺激下,正常组显示双侧枕中回（BA18）和右侧颞下回（BA37）激活,共同性斜视组激活区域显示双侧枕中回（BA18）激活;在视差3 600″刺激下,正常组显示双侧枕中回（BA18）激活,共同性斜视组无激活区.在3种不同视差刺激下,正常组的平均兴奋体素均高于共同性斜视组,2组差异有统计学意义（t=-3.16、-3.38、-2.47,P＜0.05）.结论 共同性斜视患者与正常人接受随机点立体图刺激后都出现枕叶激活,正常人还可见右侧颞叶激活;不同视差刺激条件下共同性斜视患者平均兴奋体素均低于正常人.

Objective To observe cortial activation areas in comitant strabismus patients in response to different disparity stereogram stimuli and to compare average activation voxels in comitant strabismus patients and normal subjects.Methods This was a case series study.Twelve subjects （mean age 16.9±3.9 years） with comitant strabismus and 10 healthy volunteers （mean age 21.2±2.7 years） were enrolled.The experiment was a block design.Three uncrossed disparity （1 200″,2 400″ and 3 600″） random-dot stereograms （RDS） were presented during the on-stimulus phase,and a black cross line fixed in the center of a white screen was displayed during the off-stimulus phase.Functional MRI data were processed with the statistical parametric mapping 5 software and t test.Results During the disparity of 1 200″ RDS stimulus,the right infferior occipital gyrus and left middle occipital gyrus （BA18） showed activation in the healthy group,and the left middle occipital gyrus （BA18） showed activation in the strabismus group.During the disparity of 2400″ RDS stimulus,and bilateral middle occipital gyruses （BA18） and the right inferior temporal gyrus （BA37） showed activation in the healthy group,and bilateral middle occipital gyruses （BA18） showed activation in the strabismus group.During the disparity of 3 600″ RDS stimulus,bilateral middle occipital gyruses （BA18） showed activation in the healthy group,but no significant activation area was observed in the strabismus group.Under three different disparity stimuli,the average activation voxels in the comitant strabismus group were significantly lower than in the healthy group （t=-3.16,-3.38,-2.47,P〈0.05）.Conclusion During RDS stimuli,bilateral occipital lobes showed activation in comitant strabismus and normal subjects.In addition,the right temporal lobe showed activation in the healthy subjects.Under different disparity stimuli,average activation voxels in comitant strabismus patients are lower than in healthy subjects.