Functional neurological symptom disorder (FNSD) is a neuropsychiatric disorder characterized by the presence of neurological symptoms in the absence of any neurological abnormality that can be linked to a known pathology. Few studies have taken interest in this subject probably because of the heterogeneity of results. It is most often a diagnosis of exclusion which often means that patients undergo many tests and find themselves erring for a diagnosis with very little satisfaction of the outcomes. A reliable imagery pattern would therefore provide some relief and confirmation for both patients and clinicians. It could also facilitate acceptation of the diagnosis and reduce the societal cost associated with FNSD for the patient. The aim of this present study was to describe a clinicoradiological correspondence algorithm of FNSD using the PET scan and SPECT scan (PoSPs) and grant the clinician with a reliable tool to facilitate the diagnosis of FNSD. A systematic review according to the 2009 PRISMA criteria statement was used to guide the review. Our study included 3 of our own consenting patients who met the Diagnostic and Statistical Manual of Mental Disorders 5^th edition criteria as well as 25 other patients from 7 different studies. Our results showed a hypoactivation with poor clinicoradiological correspondence and poor stability in time. This hypoactivation was mostly in the frontal lobe, which could explain some behavioral alterations. These findings oppose the ones found in organic pathologies and therefore should orient towards FNSD. In the light of these findings, we recommend the clinicians to perform two PoSPs, searching for clinicoradiological lack of correspondence and time stability using our algorithm.

中文翻译：

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功能性神经系统症状紊乱：一种诊断算法。

功能性神经系统症状疾病（FNSD）是一种神经精神疾病，其特征在于存在神经系统症状，而没有任何可与已知病理相关的神经系统异常。由于结果的异质性，很少有研究对此主题感兴趣。它通常是排除诊断，这通常意味着患者接受了许多检查，发现自己对诊断的认识很差，对结果的满意度非常低。因此，可靠的图像模式将为患者和临床医生提供一定的缓解和确认。它还可以促进对诊断的接受并降低患者与FNSD相关的社会成本。本研究的目的是描述使用PET扫描和SPECT扫描（PoSP）的FNSD的临床放射学对应算法，并为临床医生提供一种可靠的工具，以利于FNSD的诊断。根据2009年PRISMA标准声明进行系统的审查，以指导审查。我们的研究包括3名符合《精神障碍诊断和统计手册》的自愿患者5^第7版标准以及来自7个不同研究的25位其他患者。我们的结果表明，激活不足与临床放射学上的对应性差，时间稳定性差。这种过度激活主要发生在额叶，这可以解释一些行为改变。这些发现与自然病理学中发现的相反，因此应面向FNSD。根据这些发现，我们建议临床医生执行两个PoSP，使用我们的算法搜索临床放射学缺乏对应性和时间稳定性。