Reading skills of Japanese second-graders.

BACKGROUND: A few studies have explored the prevalence of dyslexia among children who speak Japanese as their native language by evaluating them individually by means of reading-based tasks. The present study was designed to clarify the frequency of suspected dyslexia among second-graders attending ordinary classes. METHODS: The subjects were 40 children (22 males, 18 females; 7 years 4 months-8 years 4 months; mean age, 7 years 11 months) out of 182 second-graders at a public elementary school situated in a local city. Each subject underwent a monomoraic syllable reading task, a word reading task, a non-word reading task, and a short sentence reading task. RESULTS: The scores on the four tests were not normally distributed; rather, they were strongly skewed to shorter reading time or fewer reading errors. In addition, they were significantly extended toward either longer reading time or more reading errors. Except in the non-word reading task, most subjects only made a few reading errors. Seven subjects (17.5%) showed at least one score that was more than 1.5 IQR (interquartile range) higher than the third quartile of that subject's eight scores on the four tasks. Assuming that those seven children are potentially dyslexic, at least 3.8% of second-graders (seven out of 182) are suspected to be suffering from dyslexia. CONCLUSION: It is likely that the prevalence of dyslexia in Japan is comparable to that in Europe and the US. To confirm this, a more comprehensive study on a larger scale should be implemented in the future.

Predicting executive function task scores with the Rey-Osterrieth Complex Figure.

The Boston Qualitative Scoring System (BQSS) is one of the scoring methods of the Rey-Osterrieth Complex Figure Test (ROCF). With BQSS, 17 qualitative ratings are generated, and subsequently 6 summary scores are calculated by combining several qualitative scores. Previously we showed that 5 of 6 BQSS summary scores were correlated with the scores of the several executive function tests in children. The objective of this study was to develop a new summary score which correlates with the executive function test scores more strongly than the existing summary scores. For this purpose, we conducted multiple regression analysis to predict PEN, CA, DSM of the Wisconsin Card Sorting Test Keio Version, and the Mazes scores from WISC-III, by the BQSS qualitative scores derived from ROCF drawings in copy condition. The subjects were 78 children with various neuropsychological disorders (5 years 5 months-14 years 11 months; mean: 9 years 2 months; F 22, M 56). Significant predictive models were generated for PEN, CA, and Mazes scores. Among them the models for the Mazes scores were the most accurate. The second model for the Mazes scores was most suitable for a new summary score. Its degree-of-freedom-adjusted coefficient of multiple determination and multiple correlation coefficient reached 0.467 and 0.695, respectively. A new summary score should be applied in future studies to evaluate its clinical usefulness.

Magnetoencephalogram in a postoperative case with a large skull defect.

We present a patient in whom magnetoencephalograms were successfully performed in presurgical and postsurgical evaluations. A 12-year-old boy with congenital porencephaly was admitted with refractory adversive seizures and frontal absence seizures. Ictal magnetoencephalographic dipoles with frontal absence seizures were located in the left frontal lobe, anterior to the porencephalic cyst, and concordant with the same area detected by intraoperative electrocorticography. A partial cortical excision was performed, and the patient's cranial bone flap was removed because of an epidural abscess. The frontal absences then disappeared. The magnetoencephalogram revealed that secondary bilateral synchrony of focal discharges from the lesion may have caused the generalized seizures in this patient. Because of residual partial seizures, second and third magnetoencephalograms were performed, and we detected residual spike dipoles clustering in the area posterior to the cavity of cortical excision and anterior to the porencephalic cyst. Another excision of the area between the cavity and frontal edge of the cyst was performed, and seizure frequency diminished dramatically. In this case, despite the failure of dipole estimation by electroencephalogram in the context of a large bone defect, the magnetoencephalogram was useful in detecting the residual epileptogenic zone after failed epilepsy surgery.