一侧大脑半球中部不发育中枢系余部的代偿发展

COMPENSATORY HYPERTROPHY OF THE CENTRAL STRUCTURES FOLLOWING ATROPHY OF THE MIDDLE REGION OF ONE CEREBRAL HEMISPHERE

本文描述一例八个月乳婴的脑和脊髓的异状。它们经甲醛固定,用棉胶包埋,作30微米的间歇连续切片,每隔一定距离留取一片,分装两套。此两套切片,分别用Weil和Nissl法染色。此例属脑孔洞症。左侧的大脑半球小于右侧,脑沟较深,脑回也比右侧狭窄。在此侧,岛叶缺如,也无额、顶、颞部岛盖。空缺区与侧脑室相通,表面被有增厚的膜(4×0.8厘米)。额叶、顶叶和颞叶的大部以及枕叶还都存在。左侧的锥体束不发育。中枢系有些部分有代偿的发展:右侧的锥体束(包括乖离的锥体束);左侧的锥体外系核簇——豆状核、尾状核、丘脑底核和黑貭。在小脑系,左侧结合臂及右侧的红核和橄榄下核都见增扩。左侧的薄核、楔核,右侧的内侧丘索,以及右侧脊髓的前索、后角和背核也都增大。生后器官使用的加强自然引致中枢及其它结构的增扩。本例生活期短,发育迟滞,运动机会甚少,难以影响中枢的形相。此外,在本例,中枢系的若干核团表现代偿性的增大,指证胚胎期神经细胞的有丝分裂格外旺盛。因此,这个代偿发展多是先天性的。现有的代偿理论——自行调节、机能的替代和转移等概念都不够满意。这些概念的后边有一个更基本的,尚未知的生长因素。本例表现的代偿事实较前人所见为多。我们对于代偿的理论暂不做肯定的推断。

This report deals with the brain and spinal cord of a porencephalic nursling of 8months.Intermittent serial colloidin sections were cut and stained by Nissl and Weiltechniques.The left cerebral hemisphere is smaller with deeper sulci and narrower gyri.Theinsular lobe is non-existent;and the frontal parietal and temporal opercula are all miss-ing.A cavity underlies this region and communicates with the lateral ventricle beingcovered Iaterally by a thickened membrane about 4×0.8 cm in area.Most of the front-al,parietal and temporal lobes and the whole occipital lobe are present.The left pyramidal tract is undeveloped.Compensatory hypertrophy is shown byvarious central structures such as the right pyramidal tract(together with the aberrantpyramidal bundles),and the extrapyramidal gray masses-lenticular,caudate and sub-thalamic nuclei and substantia nigra.In the cerebellar system,the brachium conjunc-tivum on the left side and the red nucleus and the inferior olivary nucleus on the rightare over-developed.Other hypertrophied structures include the left gracile and cuneatenuclei,the right lemniscus medialis,together with the anterior funiculus,posterior hornand the nucleus dorsalis in the right half of the spinal cord.The postnatal heightened use of bodily organs naturally induces an over-developmentof,besides others,the central structure.With a short life-span and retarded develop-ment,the present case had a too limited activity to influence the size of its central or-gans.Moreover,a number of central nuclear masses manifest a compensatory enlarge-ment,thus indicating a heightened mitotic activity of the nerve cells in the embryonicperiod.This hypertrophy is,them,largely prenatal.The current theories of compensation such as self-regulation,substitution and trans-fer of functions,are not explanatory and,thus,unsatisfactory.Behind such concepts,there shou1d exist a more fundamental and yet unspecified factor of growth.The pre-sent study has demonstrated more facts of compensatory development than the previousauthors.As to the theories of compensation,it is better to reserve a definite judgement.