Functional neurological symptom disorders (FNSD) pose a common challenge in clinical practice, particularly in pediatric cases where the clinical phenotypes can be intricate and easily confused with structural disturbances. The frequent coexistence of FNSDs with other medical disorders often results in misdiagnosis. In this review, we highlight the distinctions between FNSD and various psychiatric and neurological conditions. Contrary to the misconception that FNSD is a diagnosis of exclusion, we underscore its nature as a diagnosis of inclusion, contingent upon recognizing specific clinical features. However, our focus is on a critical learning point illustrated by the case of a 14-year-old male initially diagnosed with FNSD, but subsequently found to have a rare primary monogenic movement disorder (paroxysmal kinesigenic dyskinesia, PKD). The crucial takeaway from this case is the importance of avoiding an FNSD diagnosis based solely on psychiatric comorbidity and suppressible symptoms. Instead, clinicians should diligently assess for specific features indicative of FNSD, which were absent in this case. This emphasizes the importance of making a diagnosis of inclusion. Extended follow-up and clinical-oriented genetic testing might help identify comorbidities, prevent misdiagnosis, and guide interventions in complex cases, which cannot be simply classified as “functional” solely because other conditions can be excluded.

中文翻译：

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儿科功能性神经症状性疾病的误诊：叙述回顾及相关病例报告

功能性神经症状障碍（FNSD）在临床实践中构成了常见的挑战，特别是在儿科病例中，其临床表型可能很复杂，并且很容易与结构性紊乱混淆。 FNSD 与其他医学疾病频繁共存常常导致误诊。在这篇综述中，我们强调了 FNSD 与各种精神和神经系统疾病之间的区别。与 FNSD 是排除性诊断的误解相反，我们强调其本质是包容性诊断，取决于识别特定的临床特征。然而，我们的重点是一个关键的学习点，该案例说明了一名 14 岁男性的案例，该男性最初被诊断患有 FNSD，但随后发现患有罕见的原发性单基因运动障碍（阵发性运动源性运动障碍，PKD）。从这个案例中得出的关键结论是，避免仅根据精神合并症和可抑制症状进行 FNSD 诊断的重要性。相反，临床医生应认真评估指示 FNSD 的特定特征，而本例中不存在这些特征。这强调了做出包容性诊断的重要性。延长随访和面向临床的基因检测可能有助于识别合并症、防止误诊并指导复杂病例的干预措施，这些病例不能仅仅因为可以排除其他情况而简单地归类为“功能性”。