Brown Stephanie S G, Stanfield Andrew C
Patrick Wild Centre, Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh EH10 5HF, UK.
J Neurol Sci. 2015 May 15;352(1-2):19-28. doi: 10.1016/j.jns.2015.03.031. Epub 2015 Mar 27.
Expansion of the CGG repeat region of the FMR1 gene from less than 45 repeats to between 55 and 200 repeats is known as the fragile X premutation. Carriers of the fragile X premutation may develop a neurodegenerative disease called fragile X-associated tremor/ataxia syndrome (FXTAS). Recent evidence suggests that premutation carriers experience other psychiatric difficulties throughout their lifespan.
Medline, EMBASE and PsychINFO were searched for all appropriate English language studies published between January 1990 and December 2013. 419 potentially relevant articles were identified and screened. 19 articles were included in the analysis.
We discuss key structural magnetic resonance imaging (MRI) findings such as the MCP sign and white matter atrophy. Additionally, we discuss how functional MRI results have progressed our knowledge of how FXTAS may manifest, including reduced brain activation during social and memory tasks in multiple regions.
This systematic review may have been limited by the search for articles on just 3 scientific databases. Differing techniques and methods of analyses between research groups and primary research articles may have caused differences in results between studies.
Current MRI studies into the fragile X premutation have been important in the diagnosis of FXTAS and identifying potential pathophysiological mechanisms. Associations with blood based measures have also demonstrated that neurodevelopmental and neurodegenerative aspects of the fragile X premutation could be functionally and pathologically separate. Larger longitudinal studies will be required to investigate these conclusions.
FMR1基因的CGG重复区域从少于45次重复扩展到55至200次重复被称为脆性X前突变。脆性X前突变携带者可能会患上一种神经退行性疾病，称为脆性X相关震颤/共济失调综合征（FXTAS）。最近的证据表明，前突变携带者在其一生中还会经历其他精神方面的困难。
检索了1990年1月至2013年12月期间发表的所有合适的英文研究，检索数据库包括Medline、EMBASE和PsychINFO。共识别并筛选出419篇潜在相关文章，19篇文章纳入分析。
我们讨论了关键的结构磁共振成像（MRI）结果，如中脑脑桥臂征和白质萎缩。此外，我们还讨论了功能MRI结果如何增进了我们对FXTAS可能表现方式的了解，包括多个区域在社交和记忆任务期间大脑激活减少。
本系统评价可能因仅在3个科学数据库中检索文章而受到限制。研究组之间以及原始研究文章之间不同的分析技术和方法可能导致研究结果存在差异。
目前针对脆性X前突变的MRI研究在FXTAS的诊断和确定潜在病理生理机制方面具有重要意义。与血液检测指标的关联也表明，脆性X前突变的神经发育和神经退行性方面在功能和病理上可能是分开的。需要进行更大规模的纵向研究来探究这些结论。
