Background No large-scale study of the timing of autism spectrum disorder (ASD) diagnosis has been performed in Japan to date. The aim of this study was to examine sex differences and annual trends in age at diagnosis of ASD using clinical data. Methods Clinical data for children aged less than 18 years diagnosed with ASD between January 1, 2009, and December 31, 2013, and in whom follow-up was possible 1 year after diagnosis, were extracted. Results The mean age at ASD diagnosis was 7.2 ± 4.2 years and the mode age was 3 years. No sex difference was observed for age at diagnosis (p = 0.157). An annual trend of earlier diagnosis was observed when fiscal years were compared (p < 0.001). Conclusion This study highlighted the need to develop and provide appropriate early intervention methods and services for ASD children in Japan.

ABSTRACT:The purpose of this study was to apply the stepwise method of discriminant analysis to investigate the relationship among hippocampal atrophy, brain blood flow, and neuropsychological tests in patients who experienced forgetfulness. The neuropsychological tests that presented a relationship with hippocampal atrophy were Revised Hasegawa Dementia Scale and Logical memory Ⅱ. Likewise, the test that presented a relationship with the brain blood flow was Frontal Assessment Battery. These results suggest that Revised Hasegawa Dementia Scale, Logical memory Ⅱ, and Frontal Assessment Battery are useful neuropsychological tests to predict the possibility of hippocampal atrophy and decrease in brain blood flow of precuneus and posterior cingulate gyri.

Clinical data in Japan were used to examine the age at diagnosis of autism spectrum disorders (ASD) in children in Japan. Results indicate that the mean age at diagnosis for 7779 participants was 7.3±4.3 years, the mode 3.0 years, and the median 6.0 years. The male-to-female ratio was 3:1. There were no sex differences in the age at diagnosis of any ASD. Asperger's syndrome was diagnosed at older ages than other disorders, but no clear peak was indicated for the age at diagnosis. Only childhood autism was diagnosed early in life and showed an annual trend. This study suggests the need to develop a system or tool that enables early diagnosis of Asperger's syndrome, as well as the need to develop a proper early intervention techniques and service provisions for childhood autism.

More attention should be paid to unbuttoning and buttoning activities in children. It might be a simple and easy-to-use evaluation method in the clinical setting.

The development of the ability to imitate bye-bye was delayed in VLBW infants even after correction for gestational age. It was suspected that the fine motor development delay might contribute to the late appearance of bye-bye in VLBW infants. Further follow-up study is required to clarify the clinical significance.