Published papers

The current study sought to develop a new behavioral analysis methods to evaluate the effects of social skills training (SST). SST is known to be an effective method to improve the social skills of children with behavioral problems. However, current evaluation methods involve behavioral rating scales that are heavily dependent on evaluators' particular experiences they have had. To quantitatively examine the behavioral effects of SST, we examined subjects' head-movements related to social behavior, using a two-dimensional motion capture system (Kissei Comtec, Japan).   Four children (three male, one female, 7-8 years of age) with pervasive developmental disorder (PDD) or attention deficit/hyperactivity disorder (AD/HD) participated in 16 sessions of SST. Before and after SST, head-coordinates on a two-dimensional plane were calculated using their behavior during a pair task, measured by four digital cameras.   After SST, the number of communication behaviors was increased compared to before SST. In addition, children looked longer at another child within 30 degrees of the central visual field. Time-series analysis of the visual field during the detection of another child revealed significant auto-correlation from about -1.12 second. before to the beginning of communication behavior (p<0.05).   The results suggested that our method can provide a quantitative index of characteristics related to skilled social behaviors. We conclude that a two-dimensional motion capture system would be useful for visualization of the interventional effects of SST, which would supplement assessments by the conventional observational strategies.

Two hundred and seven Japanese elementary school children aged from 6 (Grade 1) to 12 (Grade 6) years old were tested for their abilities to name numbers and pictured objects along with reading Hiragana characters and words. These children all showed typical development and their classroom teachers judged that they were not having any problems with reading or writing. The children were randomly divided into two groups, the first group was assigned to two naming tasks the rapid automatized naming (RAN) of "numbers" and "pictured objects," the second group was assigned to two rapid alternative stimulus (RAS) naming tasks using numbers and pictured objects. All children were asked to perform two reading tasks that were written in Hiragana script : single mora reading task and four syllable word reading task. The total articulation time for naming and reading and performance in terms of accuracy were measured for each task. Developmental changes in these variables were evaluated. The articulation time was significantly longer for the first graders, and it gradually shortened as they moved through to the upper grades in all tasks. The articulation time reached a plateau in the 5th grade for the number naming, while gradual change continued after drastic change in the lower grades for the pictured object naming. The articulation times for the single mora reading and RAN of numbers correlated strongly. The articulation time for the RAS naming was significantly longer compared to that for the RAN, though there were very few errors. The RAS naming showed the highest correlation with the four syllable word reading. This study demonstrated that the performance in rapid automatized naming of numbers and pictures were closely related with performance on reading tasks. Thus Japanese children with reading disorders such as developmental dyslexia should also be evaluated for rapid automatized naming.

OBJECTIVES: Dysphagia is linked to mortality risk among patients with profound intellectual and multiple disabilities (PIMD); the present study therefore aimed to clarify the characteristics of hyoid movements during swallowing and to examine the mechanism of dysphagia in patients with PIMD. METHODS: A retrospective video fluoroscopic swallowing study was conducted on 43 patients with PIMD (mean age = 25.4; 25 males, 18 females) and 24 healthy adults (mean age = 44.3; 16 males, 8 females). The movements of the hyoid bone and mandible were tracked frame by frame in the video footage, and their range of movements and trajectories were analyzed. RESULTS: Most patients showed atypical movement trajectories of the hyoid, such as insufficient anterior movement and increased range of mandibular downward movement, compared with normal adults. Moreover, the mechanism of dysphagia was revealed by structural equation modeling, indicating that insufficient anterior movement could lead to pharyngeal residue in the pyriform sinus. CONCLUSION: The insufficient anterior movement of the hyoid could be caused by weak ventral suprahyoid muscles and atypical head and neck posture characteristic of patients with PIMD. It may be useful to predict pharyngeal residue from the range of hyoid movements and trajectories for the prevention of aspiration.

OBJECTIVE: To reveal whether neurodevelopmental outcome of infants after epilepsy surgery can be quantitatively assessed by electroencephalography (EEG) functional connectivity analysis. METHODS: We enrolled 13 infants with posterior quadrant dysplasia aged <2 years who were treated using posterior quadrantectomy and 21 age-matched infants. EEG was performed both before and one year after surgery. Developmental quotient (DQ) was assessed both before and 3 years after surgery. The phase lag index (PLI) of three different pairs of electrodes in the nonsurgical hemisphere, i.e., the anterior short distance (ASD), posterior short distance (PSD), and long distance (LD) pairs, were calculated as indices of brain connectivity. The relationship between the PLI and DQ was evaluated. RESULTS: Overall, 77% infants experienced seizure freedom after surgery. The beta- and gamma- range PLI of PSD pairs increased preoperatively. All these pairs normalized postoperatively. Simple linear regression analysis revealed a significant relationship between the postoperative DQ and the postoperative beta-band PLI of ASD pairs. CONCLUSION: Preoperative abnormal hyper-connectivity was normalized to the control level after surgery. The postoperative hyperconnectivity was associated with long-term neurodevelopmental improvement. SIGNIFICANCE: PLI quantifies neurodevelopmental improvements after posterior quadrantectomy.

The factors associated with the clinical outcomes of repetitive transcranial magnetic stimulation (rTMS) in patients with major depressive disorder (MDD) remain largely unexplored. Therefore, this study aimed to examine whether rTMS can change the functional laterality of the prefrontal hemodynamic response and whether baseline functional laterality can predict the clinical outcomes of rTMS using functional near-infrared spectroscopy (fNIRS). We included 19 patients with MDD who were treated with high-frequency rTMS. The verbal fluency task was used as the activation task. We calculated the laterality index (LI) based on the task-related oxygenation response in the frontal region. First, the LI was compared before and after rTMS treatment. Second, the reduction in the Montgomery-Åsberg Depression Rating Scale (MADRS) score was compared between the rightward dominance group (pre-LI < 0) and the leftward dominance group (pre-LI ≥ 0). The findings showed a significant change in the LI after rTMS treatment. The rightward dominance group had a significantly greater reduction in MADRS score than the leftward dominance group. Subsequently, the laterality of the task-related hemodynamic response of the prefrontal region shifted leftward following left high-frequency rTMS treatment. Thus, the pre-LI calculated using fNIRS data is a possible predictor of rTMS outcomes in patients with MDD.

BACKGROUND: An individual with autism spectrum disorder (ASD) has social skill, motor skill, and motion perception deficits. However, the relationship among them was not clarified. Therefore, this study aimed to evaluate the effects of motor skills on social skills and motion perception. METHODS: Five typically developed children and fourteen children with ASD participated in our study. The N200 component, a brain activity indicating motion perception, was induced in mid-temporal (MT/V5) brain area by watching a random dot kinematograph, and was recorded using a scalp electroencephalogram. Furthermore, the social responsiveness scale (SRS) indicating the social skill deficit, the developmental coordination disorder questionnaire (DCDQ) estimating the developmental coordination disorder (DCD), and the movement assessment battery for children second edition (MABC-2) indicating motor skills were recorded in the children with ASD. A hierarchical multiple regression analysis was conducted to examine the modulation effects of motor skills on the relationship between social skills and motion perception. The dependent variable was the N200 latency, and the independent variables were SRS, MABC-2, and combined MABC-2 and SRS. RESULTS: The N200 latency was more delayed in children with ASD relative that in typically developed children. Intact balance ability modulated the relationship between social skills and N200 latency in children with ASD. Within the high balance ability, when the social skills worsened, the N200 latency was shortened. CONCLUSIONS: This is the first report that intact motor skills could modulate the relationship between social skills and motion perception.

The guidelines provided by American College of Medical Genetics and Genomics (ACMG) and the Association of Molecular Pathology (AMP) (ACMG/AMP guidelines) suggest a framework for the classification of clinical variants. However, the interpretations can be inconsistent, with each definition sometimes proving to be ambiguous. In particular, there can be difficulty with interpretation of variants related to the X-linked recessive trait. To confirm whether there are biases in the interpretation of inherited traits, we reanalyzed variants reported prior to the release of the ACMG/AMP guidelines. As expected, the interpretation ratio as pathogenic or likely pathogenic was significantly lower for variants related to the X-linked recessive trait. Evaluation of variants related to the X-linked recessive trait, hence, need to consider whether the variant is identified only in males in accordance with the X-linked recessive trait. The ACMG/AMP guidelines should be revised to eliminate the bias revealed in this study.

While the negative impact of the pandemic on students' mental health has been studied around the world, very little is known about the mental health of faculty and staff. This research aims to examine mental health among Japanese faculty members who taught online courses during the COVID-19 pandemic. We recruited 537 university faculty members and assessed their mental health using the World Health Organization-Five Well-Being Index (WHO-5), both retrospectively (during the academic year before the onset of the pandemic) and during the pandemic. We also evaluated workload (number of online lectures taught and preparation time per class), difficulty in using information technology (IT) for online classes, and satisfaction with the university support service for online education. As a result, the WHO-5 score during the COVID-19 pandemic was significantly lower than before, and 33.5% of the faculty members were recognized as being at risk for mental illness during the COVID-19 pandemic. A binomial logistic regression analysis revealed two significant risk factors for mental illness-faculty members were more at risk for mental illness when they experienced difficulty in using IT for online classes, and were unsatisfied with the administrative support for online education. The deterioration of mental health during the COVID-19 was not predicted by workload, such as the number of online lectures and preparation time. These results suggest the importance of improving workplace support services, especially IT support, to prevent mental health deterioration among faculty teaching online.

BACKGROUND: Oral support during feeding was clinically provided to patients with severe motor and intellectual disabilities (SMID) for the prevention of dysphasia. The present study anatomically and functionally investigated the advantages of oral support. METHODS: A videofluoroscopic swallowing study was conducted on nine patients with SMID (age = 5-41 years; mean age = 15.0; four males, five females) and twenty-four healthy adults (age = 26-67 years; mean age = 44.3; 16 males, eight females). The movements of the hyoid bone and mandible during pharyngeal swallowing were tracked, and the pharyngeal residues were evaluated. The temporal and spatial features of the movements were compared between patients with and without oral support as well as healthy adults. RESULTS: The mandible moved downward earlier and showed larger displacement in the patients with SMID. The patients also had insufficient anterior displacement of the hyoid, which was associated with pharyngeal residue. This displacement was enhanced, and the pharyngeal residue decreased with oral support. CONCLUSIONS: Oral support to hold the mandible successfully improved hyoid excursion and reduced pharyngeal residue during swallowing, which is a simple and reliable strategy for the prevention of dysphasia in patients with SMID.

While letter-naming ability is a well-known preschool predictor of the later acquisition of literacy, little is known about an appropriate benchmark (i.e., how many letter names children must know at a given age) and how it may vary among different writing systems. The present study aimed to establish a letter-naming benchmark in Japanese Hiragana for pre-elementary children (age 5 to 6 years) and examined whether this benchmark predicts risk or success in later reading development via a one-year longitudinal survey. Children (N = 291) were assessed once in their pre-elementary year for Hiragana-naming accuracy and once in their first-grade year for oral reading fluency. As a result, the ability to name 40 of 45 letters was determined to be an optimal cut-off, and failure to meet it strongly predicted a risk of deficient reading fluency in first grade. These findings support the notion that Japanese children without near-perfect mastery of Hiragana-naming in their pre-elementary year are at great risk of reading difficulty in first grade. In addition, possible contrasts between Hiragana- and alphabet-naming indicated a need for further research in different languages and scripts to establish appropriate goals and policies for this foundational skill of reading in early education.

Objective: Tourette syndrome (TS) is a neurobehavioral disorder characterized by motor and vocal tics. Simple tics are purposeless involuntary movements that spontaneously resolve during middle adolescence. Complex tics appear to be semi-voluntary movements that may become intractable when associated with obsessive–compulsive disorder (OCD). Sensory tics or urges preceded by tics suggest sensorimotor processing impairment in TS. We aimed to clarify its pathophysiology by exploring the pre-movement gating (attenuation) of somatosensory evoked potentials (SEPs). Methods: We examined 42 patients (aged 9–48 years), 4 of whom underwent follow-up assessment, along with 19 healthy controls. We defined patients with only simple tics as TS-S and patients with complex tics as TS-C. Pre-movement gating of SEPs was assessed using a previously described method. Frontal N30 (FrN30) amplitudes were compared between pre-movement and resting states. The gating ratio of pre-movement/resting amplitude of the FrN30 component was assessed: the larger the ratio, the less the gating. Results: The gating ratio for TS-C patients was larger than that of TS-S patients and healthy controls, but a statistical difference between TS-S and TS-C appeared after 15 years and over (p < 0.001). There were no significant differences in the gating ratio between TS-S patients and healthy controls. The gating ratio was related to the severity of OCD (p < 0.05). Conclusion: Sensorimotor processing was preserved for simple tics but impaired in complex tics, specifically after middle adolescence. Our study supports an age-dependent dysfunction of both motor and non-motor cortico-striato-thalamo-cortical circuits in complex tics. SEP gating seems promising as a tool for assessing age-dependent sensorimotor disintegration in TS.

AIM: Prevalence estimates of neurodevelopmental disorders have been calculated by questionnaire surveys scored by a single rater, which introduces inherent rater biases. The present study aimed to estimate the prevalence and comorbidity rates of four neurodevelopmental disorders based on both parent and teacher rating scales. METHODS: We performed a community sample survey recruiting 3852 children aged 6 to 9 years. Parents and teachers evaluated clinical conditions in children using questionnaire-style scales. These scales with cut-off values were used to estimate the prevalence and comorbidity rates of attention deficit hyperactive disorder, autism spectrum disorder, specific learning disorder (or developmental dyslexia), and developmental coordination disorder. RESULTS: The prevalence estimates were separately confirmed according to the raters. Some estimates were higher than those in previous studies conducted in other countries. We also found a large disagreement between the parent and teacher rating scores. Moreover, the degree of agreement between two raters varied depending on the severity of the child's clinical condition. CONCLUSION: These estimates are the first findings based on evaluating children by two different raters. The prevalence and comorbidity estimates are informative for researchers and clinicians of pediatric neurology. The disagreements between two different raters raise questions about previous estimates of neurodevelopmental disorders.

This study aimed to reveal changes in the quality of life (QOL) of children with neurodevelopmental disorders and their parents, and the interaction between their QOL and parental mental state during the coronavirus 2019 (COVID-19) pandemic. Eighty-nine school-aged children and parents participated in surveys in May 2020 (T1) and May 2021 (T2). The parents completed questionnaires that assessed their QOL, depression, parenting stress, and living conditions. Children's temporary mood status was evaluated using the self-reported visual analog scale (VAS). Children's QOL and VAS at T2 were higher than their QOL at T1. Parents' QOL at T2 was lower than their QOL at T1. Severe parental depression at T1 had a synergistic effect on severe parenting stress and severe depressive state at T2. Additionally, children's high QOL at T1 had a synergistic effect on low parenting stress and children's high QOL at T2. Furthermore, children's low VAS scores and parents' low QOL at T2 were associated with deterioration of family economic status. Children and parents' QOL changed during the prolonged COVID-19 pandemic. Improvement in children's QOL was influenced by reduced maternal depressive symptoms. Public support for parental mental health is important to avoid decreasing QOL.