University of Brasilia, Radiology Department, Brasilia, DF, Brazil.
Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD, USA.
J Psychiatr Res. 2023 Aug;164:259-269. doi: 10.1016/j.jpsychires.2023.06.016. Epub 2023 Jun 16.
Accumulating evidence suggests that post-traumatic stress disorder (PTSD) may increase the risk of various types of dementia. Despite the large number of studies linking these critical conditions, the underlying mechanisms remain unclear. The past decade has witnessed an exponential increase in interest on brain imaging research to assess the neuroanatomical underpinnings of PTSD. This systematic review provides a critical assessment of available evidence of neuroimaging correlates linking PTSD to a higher risk of dementia.
The EMBASE, PubMed/MEDLINE, and SCOPUS electronic databases were systematically searched from 1980 to May 22, 2021 for original references on neuroimaging correlates of PTSD and risk of dementia. Literature search, screening of references, methodological quality appraisal of included articles as well as data extractions were independently conducted by at least two investigators. Eligibility criteria included: 1) a clear PTSD definition; 2) a subset of included participants must have developed dementia or cognitive impairment at any time point after the diagnosis of PTSD through any diagnostic criteria; and 3) brain imaging protocols [structural, molecular or functional], including whole-brain morphologic and functional MRI, and PET imaging studies linking PTSD to a higher risk of cognitive impairment/dementia.
Overall, seven articles met eligibility criteria, comprising findings from 366 participants with PTSD. Spatially convergent structural abnormalities in individuals with PTSD and co-occurring cognitive dysfunction involved primarily the bilateral frontal (e.g., prefrontal, orbitofrontal, cingulate cortices), temporal (particularly in those with damage to the hippocampi), and parietal (e.g., superior and precuneus) regions.
A meta-analysis could not be performed due to heterogeneity and paucity of measurable data in the eligible studies.
Our systematic review provides putative neuroimaging correlates associated with PTSD and co-occurring dementia/cognitive impairment particularly involving the hippocampi. Further research examining neuroimaging features linking PTSD to dementia are clearly an unmet need of the field. Future imaging studies should provide a better control for relevant confounders, such as the selection of more homogeneous samples (e.g., age, race, education), a proper control for co-occurring disorders (e.g., co-occurring major depressive and anxiety disorders) as well as the putative effects of psychotropic medication use. Furthermore, prospective studies examining imaging biomarkers associated with a higher rate of conversion from PTSD to dementia could aid in the stratification of people with PTSD at higher risk for developing dementia for whom putative preventative interventions could be especially beneficial.
越来越多的证据表明，创伤后应激障碍（PTSD）可能会增加各种类型痴呆的风险。尽管有大量研究将这些关键疾病联系起来，但潜在机制仍不清楚。在过去的十年中，人们对脑影像学研究产生了浓厚的兴趣，以评估 PTSD 的神经解剖学基础。本系统评价对 PTSD 与痴呆风险相关的神经影像学相关性的现有证据进行了批判性评估。
从 1980 年到 2021 年 5 月 22 日，我们系统地检索了 EMBASE、PubMed/MEDLINE 和 SCOPUS 电子数据库，以获取有关 PTSD 神经影像学相关性和痴呆风险的原始参考文献。文献检索、参考文献筛选、纳入文章的方法学质量评估以及数据提取均由至少两名研究人员独立进行。纳入标准包括：1）明确的 PTSD 定义；2）纳入的部分参与者必须通过任何诊断标准，在 PTSD 诊断后的任何时间点发展为痴呆或认知障碍；3）脑成像方案[结构、分子或功能]，包括全脑形态和功能 MRI 以及 PET 成像研究，将 PTSD 与认知障碍/痴呆的高风险联系起来。
总体而言，有 7 篇文章符合纳入标准，共纳入 366 名 PTSD 患者。伴有认知功能障碍的 PTSD 患者的空间上集中的结构异常主要涉及双侧额叶（例如前额叶、眶额皮质、扣带回皮质）、颞叶（特别是海马损伤的患者）和顶叶（例如，顶上小叶和楔前叶）。
由于纳入研究中的数据存在异质性和缺乏可衡量性，因此无法进行荟萃分析。
我们的系统评价提供了与 PTSD 和并发痴呆/认知障碍相关的神经影像学相关性，特别是涉及海马的相关性。进一步研究检查将 PTSD 与痴呆联系起来的神经影像学特征显然是该领域尚未满足的需求。未来的影像学研究应更好地控制相关混杂因素，例如选择更同质的样本（例如，年龄、种族、教育）、适当控制并发疾病（例如，并发重度抑郁和焦虑障碍）以及精神药物使用的潜在影响。此外，研究与 PTSD 向痴呆转化率较高相关的影像学生物标志物，有助于对痴呆风险较高的 PTSD 患者进行分层，对这些患者进行潜在的预防干预可能特别有益。
