Chronic epilepsy has been associated with hippocampal abnormalities like neuronal loss, gliosis and granule cell dispersion. The granule cell layer of a normal human hippocampal dentate gyrus is traditionally regarded as a compact neuron-dense layer. Histopathological studies of surgically resected or autopsied hippocampal samples primarily from temporal lobe epilepsy patients, as well as animal models of epilepsy, describe variable patterns of granule cell dispersion including focal cell clusters, broader thick segments, and bilamination or "tram-tracking". Although most studies have implicated granule cell dispersion as a specific feature of chronic epilepsy, very few "non-seizure" controls were included in these published investigations. Our retrospective survey of 147 cadaveric pediatric human hippocampi identified identical morphological spectra of granule cell dispersion in both normal and seizure-affected brains. Moreover, sections across the entire antero-posterior axis of a control cadaveric hippocampus revealed repetitive occurrence of different morphologies of the granule cell layer - compact, focally disaggregated and bilaminar. The results indicate that granule cell dispersion is within the spectrum of normal variation and not unique to patients with epilepsy. We speculate that sampling bias has been responsible for an erroneous dogma, which we hope to rectify with this investigation.

中文翻译：

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海马颗粒细胞分散：在没有癫痫病史的小儿患者中是非特异性的发现。

慢性癫痫与海马异常有关，如神经元丢失，神经胶质增生和颗粒细胞分散。正常人海马齿状回的颗粒细胞层传统上被视为紧凑的神经元致密层。对主要来自颞叶癫痫患者的手术切除或尸体解剖的海马样本以及癫痫动物模型的组织病理学研究描述了颗粒细胞分散的可变模式，包括局部细胞簇，较宽的较厚节段以及分层或“电车追踪”。尽管大多数研究都将粒细胞的分散作为慢性癫痫的特征，但在这些已发表的研究中几乎没有“非癫痫发作”对照。我们对147具尸体小儿人海马体的回顾性调查确定了正常和癫痫发作的大脑中颗粒细胞弥散性的形态学光谱相同。而且，在对照尸体海马的整个前后轴上的切片揭示出颗粒细胞层的不同形态的重复出现-紧凑，局部分解和双唇。结果表明，颗粒细胞分散在正常变异范围内，并非癫痫患者独有。我们推测抽样偏差是造成错误教条的原因，我们希望通过本次调查予以纠正。对照尸体海马的整个前后轴断面显示颗粒细胞层的不同形态重复出现-紧凑，局部分解和双唇。结果表明，颗粒细胞分散在正常变异范围内，并非癫痫患者独有。我们推测抽样偏差是造成错误教条的原因，我们希望通过本次调查来纠正这一错误。对照尸体海马的整个前后轴断面显示颗粒细胞层的不同形态重复出现-紧凑，局部分解和双唇。结果表明，颗粒细胞分散在正常变异范围内，并非癫痫患者独有。我们推测抽样偏差是造成错误教条的原因，我们希望通过本次调查来纠正这一错误。