Katayama T, Sakamoto N, Kuroda K, Yahara O, Ugawa Y
1st Department of Internal Medicine, Asahikawa Medical College, Japan.
Rinsho Shinkeigaku. 1998 May;38(5):418-22.
We have studied function of the corpus callosum in a patient with spastic paraparesis with mental deterioration and markedly thin corpus callosum using magnetic stimulation methods. In a 21-year-old woman with slowly progressive gait disturbance, neurological examination showed mental deterioration, euphoria, spastic paraparesis, bilateral Babinski's sign, and hyperesthesia caudal to the eighth thoracic level. No abnormalities were observed in electroencephalograms. Magnetic resonance imaging (MRI) studies of the brain showed cerebral cortical atrophy, markedly thin corpus callosum, and dilated cavum septum pellucidum and cavum Vergae, but spinal cord MRIs showed no abnormalities. The lysosomal enzyme activities, whose reduction was known to cause leukodystrophy, were all normal. Very long chain fatty acid was not increased in her blood, which is against adrenoleukodystrophy. She had no anti-HTLV-1 virus antibody. Based on these clinical features and the results of biochemical analyses, we diagnosed this patient as having spastic paraplegia associated with hypoplasia of the corpus callosum (Nojima and Iwabuchi). We performed three studies on the central motor pathways in this patient. The latencies of responses recorded from upper or lower limb muscles were all within the normal range, despite that the thresholds were slightly increased. This suggests that axonal degeneration occurs in the central motor pathways, which is consistent with the autopsy findings of a patient with hereditary spastic paraplegia associated with hypoplasia of the corpus callosum. Connection between the bilateral motor cortices was investigated by magnetic stimulation of both motor cortices. The suppression of the motor cortex evoked by stimulation of the contralateral motor cortex through the corpus callosum was absent in this patient. Intracortical inhibition within the motor cortex was demonstrated to be normal by a paired-magnetic stimulation technique. Based on the results of these results of these two experiments, we conclude that the function of the corpus callosum was disturbed in the present patient. This report first shows the functional abnormality of the extremely thin corpus callosum in a patient with hereditary spastic paraplegia associated with hypoplasia of the corpus callosum.
我们采用磁刺激方法，对一名患有痉挛性截瘫、精神衰退且胼胝体明显变薄的患者的胼胝体功能进行了研究。一名21岁女性，步态障碍进展缓慢，神经系统检查显示有精神衰退、欣快感、痉挛性截瘫、双侧巴宾斯基征，以及胸8水平以下感觉过敏。脑电图未观察到异常。脑部磁共振成像（MRI）研究显示大脑皮质萎缩、胼胝体明显变薄、透明隔腔和韦尔加腔扩大，但脊髓MRI未显示异常。已知其减少会导致脑白质营养不良的溶酶体酶活性均正常。她血液中的极长链脂肪酸未增加，可排除肾上腺脑白质营养不良。她没有抗人类嗜T淋巴细胞病毒1型（HTLV-1）抗体。基于这些临床特征和生化分析结果，我们将该患者诊断为与胼胝体发育不全相关的痉挛性截瘫（野岛和岩渊）。我们对该患者的中枢运动通路进行了三项研究。尽管阈值略有升高，但从上肢或下肢肌肉记录的反应潜伏期均在正常范围内。这表明中枢运动通路发生了轴突变性，这与一名与胼胝体发育不全相关的遗传性痉挛性截瘫患者的尸检结果一致。通过对双侧运动皮质进行磁刺激，研究了双侧运动皮质之间的连接。该患者不存在通过胼胝体由对侧运动皮质刺激诱发的运动皮质抑制。通过配对磁刺激技术证明运动皮质内的皮质内抑制正常。基于这两项实验的结果，我们得出结论，该患者的胼胝体功能受到了干扰。本报告首次展示了一名与胼胝体发育不全相关的遗传性痉挛性截瘫患者中极薄胼胝体的功能异常。
