Moll Jorge, de Oliveira-Souza Ricardo
*D'Or Institute for Research and Education (IDOR) the †Federal University of the State of Rio de Janeiro (Uni-Rio), Rio de Janeiro, Brazil.
Cogn Behav Neurol. 2017 Sep;30(3):102-115. doi: 10.1097/WNN.0000000000000135.
The concept of left hemispheric dominance for praxis, speech, and language has been one of the pillars of neurology since the mid-19th century. In 1906, Hermann Oppenheim reported a patient with bilateral stereoagnosia (astereognosis) caused by a left parietal lobe tumor and proposed that the left hemisphere was also dominant for stereognosis. Surprisingly, few cases of bilateral stereoagnosia caused by a unilateral cerebral lesion have been documented in the literature since then. Here we report a 75-year-old right-handed man who developed bilateral stereoagnosia after suffering a small infarct in the crown of the left postcentral gyrus. He could not recognize objects with either hand, but retained the ability to localize stimuli applied to the palm of his left (ipsilesional) hand. He was severely disabled in ordinary activities requiring the use of his hands. The lesion corresponded to Brodmann area 1, where probabilistic anatomic, functional, and electrophysiologic studies have located one of the multiple somatosensory representations of the hand. The lesion was in a strategic position to interrupt both the processing of afferent tactile information issuing from the primary somatosensory cortex (areas 3a and 3b) and the forward higher-order processing in area 2, the secondary sensory cortex, and the contralateral area 1. The lesion also deprived the motor hand area of its afferent regulation from the sensory hand area (grasping), while leaving intact the visuomotor projections from the occipital cortex (reaching). Our patient supports Oppenheim's proposal that the left postcentral gyrus of some individuals is dominant for stereognosis.
自19世纪中叶以来，左半球在运用、言语和语言方面占主导地位这一概念一直是神经学的支柱之一。1906年，赫尔曼·奥本海姆报告了一名因左侧顶叶肿瘤导致双侧立体失认（实体觉丧失）的患者，并提出左半球在实体觉方面也占主导地位。令人惊讶的是，自那时起，文献中记录的由单侧脑损伤引起双侧立体失认的病例很少。在此，我们报告一名75岁右利手男性，他在左侧中央后回顶部发生小面积梗死之后出现了双侧立体失认。他两只手都无法识别物体，但仍保留了定位施加于其左手（患侧）手掌刺激的能力。在需要使用双手的日常活动中，他严重残疾。该病变对应于布罗德曼第1区，在此区域，概率性解剖学、功能和电生理学研究确定了手部多个体感表征之一。该病变处于一个关键位置，既能中断从初级体感皮层（3a区和3b区）发出的传入触觉信息的处理，也能中断在第2区、次级感觉皮层和对侧第1区的向前高阶处理。该病变还使运动手部区域失去了来自感觉手部区域（抓握）的传入调节，而枕叶皮层（够物）的视觉运动投射则保持完整。我们的患者支持奥本海姆的提议，即某些个体的左侧中央后回在实体觉方面占主导地位。
