Introduction

The olfactory system is associated with several brain areas that might be involved in neurodegenerative processes and neurodevelopmental disorders. For this reason, investigation of the olfactory function plays an important role in the assessment of individuals with autism spectrum disorder (ASD), a neurodevelopmental disorder characterized by an impairment in social communication and by a restricted and repetitive pattern of behaviors. The aim of this study was to examine odor detection threshold, discrimination, and identification in participants with ASD compared to typically developing (TD) controls.

Methods

Thirty Italian subjects (15 with ASD, mean age 19 ± 0.5 years, and 15 TD controls, mean age 21.7 ± 0.4 years) were evaluated by means of the Sniffin’ Sticks extended test through three different parameters, odor detection threshold, discrimination, and identification, and their sum the threshold, discrimination, and identification (TDI) score.

Results

Our results indicated that the participants with ASD showed an impairment in odor detection threshold and TDI score compared to TD controls. No differences were found in odor identification and discrimination. Participants with ASD were significantly poorer in correctly identifying the following odors: leather, apple, rose, cinnamon, garlic, cloves, and anis. However, they were significantly better than TD controls in correctly identifying the odor of the following fruits: orange, banana, and lemon.

Conclusion and Implications

Our data provide a comprehensive evaluation of the three olfactory components in an Italian population and confirm an impaired odor detection threshold and TDI score in subjects with ASD compared to TD controls. In conclusion, these results suggest that the Sniffin’ Sticks extended test might be a valid tool in early detection and differential diagnosis of neurodevelopmental disorders.

中文翻译：

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自闭症谱系障碍意大利受试者的嗅觉功能评估

介绍

嗅觉系统与可能与神经变性过程和神经发育障碍有关的几个大脑区域有关。因此，嗅觉功能的调查在自闭症谱系障碍（ASD）患者的评估中起着重要作用，自闭症谱系障碍是一种以社交沟通障碍和行为方式受限且重复的行为为特征的神经发育障碍。这项研究的目的是检查与典型开发（TD）对照相比，ASD参与者的气味检测阈值，辨别力和识别力。

方法

30名意大利受试者（15名ASD，平均年龄19±0.5岁，和15名TD对照，平均年龄21.7±0.4岁）通过Sniffin's Sticks扩展测试通过三个不同的参数，气味检测阈值，辨别力和识别及其总和的阈值，歧视和识别（TDI）得分。

结果

我们的结果表明，与TD对照组相比，患有ASD的参与者在气味检测阈值和TDI评分上均存在损伤。在气味识别和辨别上没有发现差异。患有ASD的参与者在正确识别以下气味方面明显较差：皮革，苹果，玫瑰，肉桂，大蒜，丁香和茴香。但是，在正确识别以下水果的气味方面，它们比TD对照要好得多：橙色，香蕉和柠檬。

结论与启示

我们的数据提供了对意大利人群中三种嗅觉成分的综合评估，并证实了与TD对照相比，ASD患者的气味检测阈值和TDI得分受损。总之，这些结果表明，Sniffin's Sticks延伸试验可能是早期发现和鉴别诊断神经发育障碍的有效工具。