Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Department of Psychiatry & Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Acta Neuropathol Commun. 2024 Feb 22;12(1):31. doi: 10.1186/s40478-024-01738-7.
Pick's disease (PiD) is a subtype of the tauopathy form of frontotemporal lobar degeneration (FTLD-tau) characterized by intraneuronal 3R-tau inclusions. PiD can underly various dementia syndromes, including primary progressive aphasia (PPA), characterized by an isolated and progressive impairment of language and left-predominant atrophy, and behavioral variant frontotemporal dementia (bvFTD), characterized by progressive dysfunction in personality and bilateral frontotemporal atrophy. In this study, we investigated the neocortical and hippocampal distributions of Pick bodies in bvFTD and PPA to establish clinicopathologic concordance between PiD and the salience of the aphasic versus behavioral phenotype. Eighteen right-handed cases with PiD as the primary pathologic diagnosis were identified from the Northwestern University Alzheimer's Disease Research Center brain bank (bvFTD, N = 9; PPA, N = 9). Paraffin-embedded sections were stained immunohistochemically with AT8 to visualize Pick bodies, and unbiased stereological analysis was performed in up to six regions bilaterally [middle frontal gyrus (MFG), superior temporal gyrus (STG), inferior parietal lobule (IPL), anterior temporal lobe (ATL), dentate gyrus (DG) and CA1 of the hippocampus], and unilateral occipital cortex (OCC). In bvFTD, peak neocortical densities of Pick bodies were in the MFG, while the ATL was the most affected in PPA. Both the IPL and STG had greater leftward pathology in PPA, with the latter reaching significance (p < 0.01). In bvFTD, Pick body densities were significantly right-asymmetric in the STG (p < 0.05). Hippocampal burden was not clinicopathologically concordant, as both bvFTD and PPA cases demonstrated significant hippocampal pathology compared to neocortical densities (p < 0.0001). Inclusion-to-neuron analyses in a subset of PPA cases confirmed that neurons in the DG are disproportionately burdened with inclusions compared to neocortical areas. Overall, stereological quantitation suggests that the distribution of neocortical Pick body pathology is concordant with salient clinical features unique to PPA vs. bvFTD while raising intriguing questions about the selective vulnerability of the hippocampus to 3R-tauopathies.
皮克病(PiD)是额颞叶变性(FTLD-tau)tau 病亚型的一种,其特征是神经元内存在 3R-tau 包涵体。PiD 可能导致各种痴呆综合征,包括原发性进行性失语症(PPA),其特征是孤立且进行性的语言障碍和左侧优势萎缩;以及行为变异型额颞叶痴呆(bvFTD),其特征是人格进行性障碍和双侧额颞叶萎缩。在这项研究中,我们研究了 bvFTD 和 PPA 中 Pick 体的新皮质和海马分布,以在 PiD 和语言表型与行为表型的显著性之间建立临床病理一致性。从西北大学阿尔茨海默病研究中心脑库中确定了 18 例以 PiD 为主要病理诊断的右利手病例(bvFTD,N=9;PPA,N=9)。使用 AT8 对石蜡包埋切片进行免疫组织化学染色以可视化 Pick 体,并在多达六个双侧区域[中额回(MFG)、上颞回(STG)、下顶叶回(IPL)、前颞叶(ATL)、齿状回(DG)和海马 CA1]和单侧枕叶皮层(OCC)进行无偏立体学分析。在 bvFTD 中,Pick 体的皮质密度峰值出现在 MFG,而在 PPA 中则是 ATL 受影响最大。PPA 中 IPL 和 STG 的左侧病变程度更大,后者达到显著水平(p<0.01)。在 bvFTD 中,STG 的 Pick 体密度存在明显的右侧偏侧性(p<0.05)。海马体负担与临床病理不一致,因为与皮质密度相比,bvFTD 和 PPA 病例均显示出明显的海马体病理学(p<0.0001)。在 PPA 病例的一个亚组中进行的包涵体-神经元分析证实,与新皮质区域相比,DG 中的神经元包涵体负担不成比例。总体而言,立体学定量表明,新皮质 Pick 体病理学的分布与 PPA 与 bvFTD 独特的显著临床特征一致,同时提出了关于海马体对 3R-tau 病易感性的有趣问题。