Clínica Diagnóstico Avançado por Imagem - DAPI, Curitiba, PR, Brazil.
Clínica Diagnóstico Avançado por Imagem - DAPI, Curitiba, PR, Brazil; Epilepsy and EEG Service, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil.
Epilepsy Behav. 2019 Nov;100(Pt A):106516. doi: 10.1016/j.yebeh.2019.106516. Epub 2019 Sep 28.
Neuropsychological tests can infer the lateralization of the epileptogenic focus, associating verbal memory to mesial structures in the left temporal lobe and visual or nonverbal memory to the right side. High-field magnetic resonance imaging (MRI) with high-resolution protocols allows acquisitions suitable for advanced postprocessing with precise volumetry of brain structures, and functional MRI demonstrates evidence that epilepsy should be seen as a network pathology, involving several structures in the brain. Since the literature showing associations between the volumetry of brain structures in left and right mesial temporal lobe epilepsy (MTLE) and verbal and visual memory performance on neuropsychological tests is conflicting, we revisited these relationships, considering the hippocampal volumetry of patients with unilateral MTLE.
Automatized hippocampal volumes were obtained using FreeSurfer software from MRI exams of 35 patients with unilateral MTLE and hippocampal atrophy and homolateral ictal onset zone defined by video electroencephalography concordant to the side of hippocampal volume reduction (15 on the left side). Verbal memory was assessed using the Rey Auditory-Verbal Learning Test (RAVLT), and visual memory tests employed the Rey-Osterrieth Complex Figure Test (ROCFT). The statistical analysis explored relationships between hippocampal volumetry, lateralization, and performance on memory tests.
In general, we observed deficits in both verbal and visual memory for patients with left and right hippocampal volume reduction. Patients with left hippocampal volume reduction had poorer performance on verbal memory tests compared with those with right hippocampal atrophy (t = -3.813, p < 0.001). Visual memory deficits were seen on both left and right MTLE without a statistically significant difference (t = 0.074, p = 0.942). The correlation between the Hippocampal Asymmetry Index (HAI) and visual and verbal Z-scores was significant only for visual Z-score in right MTLE (R = -0.45, p = 0.048).
Verbal memory deficit seems to be more consistent in patients with left hippocampal volume reduction. Although it had only a moderate correlation to HAI, visual memory deficit is suggested as a poorer indicator for right MTLE. Considering that verbal and visual memory deficits are seen on both right and left MTLE, MTLE should not be regarded as a unilateral, focal, or local insult but as a multifactorial and network pathology, possibly involving several brain structures.
神经心理学测试可以推断致痫灶的偏侧性，将言语记忆与左侧颞叶内侧结构相关联，将视觉或非言语记忆与右侧相关联。具有高分辨率方案的高磁场磁共振成像（MRI）允许进行适合于脑结构精确容积的高级后处理的采集，并且功能 MRI 证明了癫痫应该被视为网络病理学，涉及大脑中的几个结构。由于文献表明左、右侧颞叶内侧癫痫（MTLE）的脑结构容积与神经心理学测试中言语和视觉记忆表现之间存在关联，但存在冲突，因此我们重新研究了这些关系，同时考虑了单侧 MTLE 患者的海马容积。
使用 FreeSurfer 软件从 35 例单侧 MTLE 患者的 MRI 检查中自动获得海马体容积，这些患者的 MRI 检查表现为海马体萎缩和同侧致痫灶起始区（15 例在左侧），通过视频脑电图检查与海马体容积减少的侧位相匹配。使用 Rey 听觉言语学习测试（RAVLT）评估言语记忆，使用 Rey-Osterrieth 复杂图形测试（ROCFT）评估视觉记忆。统计分析探索了海马体容积、偏侧性和记忆测试表现之间的关系。
总的来说，我们观察到左侧和右侧海马体容积减少的患者在言语和视觉记忆方面都存在缺陷。与右侧海马体萎缩的患者相比，左侧海马体容积减少的患者在言语记忆测试中的表现更差（t=-3.813，p<0.001）。在左、右侧 MTLE 患者中均观察到视觉记忆缺陷，但无统计学差异（t=0.074，p=0.942）。仅在右侧 MTLE 中，海马不对称指数（HAI）与视觉和言语 Z 分数之间的相关性具有统计学意义（R=-0.45，p=0.048）。
在左侧海马体容积减少的患者中，言语记忆缺陷似乎更为一致。尽管它与 HAI 只有中度相关性，但视觉记忆缺陷被认为是右侧 MTLE 的较差指标。考虑到在左、右侧 MTLE 患者中都存在言语和视觉记忆缺陷，MTLE 不应被视为单侧、局灶性或局部损伤，而应被视为多因素和网络病理学，可能涉及多个脑结构。
