Levy L M, Henkin R I, Lin C S, Hutter A, Schellinger D
Department of Radiology, Georgetown University Hospital, Washington, D.C., USA.
J Comput Assist Tomogr. 1998 Sep-Oct;22(5):760-70. doi: 10.1097/00004728-199809000-00019.
Our goal was to demonstrate that medical therapy in patients with smell loss (hyposmia) that restored olfactory function toward or to normal could be verified and quantitated by functional MRI (fMRI) of brain and that visual representation of these changes could be used to identify these patients.
Multislice FLASH MR or echo planar MR brain scans were obtained in four patients with hyposmia in response to three olfactory stimuli both before and after treatment with theophylline. Activation images were derived using correlation analysis, and ratios of brain area activated to total brain area were obtained.
Prior to treatment, all patients stated that they could not smell; these losses were confirmed by standard psychophysical tests. At this time, fMRI brain activation in response to odors was significantly less than that measured in normal volunteers and similar to activation measured previously in other patients with a similar type of hyposmia. After treatment, subjective smell function improved in three patients and no improvement occurred in one; results were confirmed by psychophysical tests. In each patient in whom smell acuity improved, brain activation in response to each odor increased in each section and mean activation increased significantly for each odor. Activation increased in all regions previously associated with olfactory stimulation and was particularly apparent in orbitofrontal cortex, frontal lobe component of cingulate gyri, temporal lobe gyri, and hippocampus. There also was consistent activation in superior, middle, and inferior frontal lobe gyri. There were no changes in brain activation after treatment in the patient in whom smell did not improve.
These results demonstrate that theophylline is an effective therapeutic agent to correct hyposmia in some patients with smell loss. These changes have been documented by fMRI brain scans using olfactory stimuli. This is the first study in which this type of objective improvement following medical treatment has been demonstrated in patients with hyposmia.
我们的目标是证明，对于嗅觉减退（嗅觉减退）患者，能够恢复嗅觉功能至正常或接近正常的药物治疗可以通过大脑功能磁共振成像（fMRI）进行验证和定量，并且这些变化的视觉表现可用于识别这些患者。
对4例嗅觉减退患者在使用茶碱治疗前后，针对三种嗅觉刺激进行多层快速成像（FLASH）磁共振或回波平面磁共振脑扫描。使用相关性分析得出激活图像，并获得激活的脑区面积与全脑面积的比值。
治疗前，所有患者均表示无法闻到气味；这些嗅觉丧失通过标准心理物理学测试得到证实。此时，对气味产生反应的功能磁共振成像脑激活明显低于正常志愿者所测结果，且与先前在其他类似类型嗅觉减退患者中测得的激活情况相似。治疗后，3例患者的主观嗅觉功能有所改善，1例无改善；结果通过心理物理学测试得到证实。在嗅觉敏锐度提高的每位患者中，每个脑区对每种气味的激活均增加，且每种气味的平均激活显著增加。在先前与嗅觉刺激相关的所有区域激活均增加，在眶额皮质、扣带回的额叶部分、颞叶脑回和海马体中尤为明显。额上回、额中回和额下回也有持续激活。嗅觉未改善的患者治疗后脑激活无变化。
这些结果表明，茶碱是纠正某些嗅觉减退患者嗅觉减退的有效治疗药物。这些变化已通过使用嗅觉刺激的功能磁共振成像脑扫描记录下来。这是第一项在嗅觉减退患者中证明药物治疗后出现这种客观改善的研究。
