Efficacy and safety of vigabatrin in Japanese patients with infantile spasms: Primary short-term study and extension study.

Vigabatrin was approved for the treatment of infantile spasms by the US Food and Drug Administration, but not in Japan at the time of initiating this clinical study because of concerns about irreversible peripheral visual field defects (VFDs). This study evaluated the efficacy and safety of vigabatrin for Japanese patients with infantile spasms. Of 15 patients (aged ≥4weeks and <2years) enrolled, with the exception of two patients who did not receive vigabatrin, 13 were treated with a titrated dosage of vigabatrin (50-150mg/kg/day; limited to 3000mg/day). Twelve out of 13 patients receiving vigabatrin had spasms that were treatment refractory; these patients were concurrently treated with at least one other antiepileptic drug. One patient received vigabatrin monotherapy. Eight of the 13 patients (61.5% [95% CI: 31.6-86.1%]) had a ≥50% reduction during the dose-adjustment phase compared with baseline in the frequency of spasms, with efficacy maintained through a 2-week maintenance phase. Spasms disappeared in six out of nine patients (66.7% [95% CI: 29.9-92.5%]) who transitioned to the maintenance phase and hypsarrhythmia on electroencephalography also resolved in four patients. Hypsarrhythmia was improved in another two patients. Six out of seven patients who continued treatment through Week 32 of an extension study reported ongoing efficacy for vigabatrin. The most common adverse events (AEs) were psychiatric disorders and nervous system disorders (n=8; 61.5%) that were generally mild in severity. No treatment-related peripheral VFDs were observed. No severe AEs or AEs resulting in discontinuation of vigabatrin therapy were reported. An abnormality in magnetic resonance images was observed in one patient during the extension period. Vigabatrin was deemed to be clinically effective and well tolerated in Japanese patients with infantile spasms.

[New antiepileptic drugs: characteristics and clinical applications].

New antiepileptic drugs (AEDs) that have been used in many other countries for more than 10 years have only recently became available for use in Japan. Gabapentin, topiramate, lamotrigine and levetiracetam were licensed for use in Japan between 2006 and 2010. Stiripentol for Dravet syndrome and rufinamide for Lennox-Gastaut syndrome were also approved in 2012 and 2013 as orphan drugs. Clinical trials of other new AEDs such as oxcarbazepine, vigabatrin, lacosamide, and perampanel are in progress. In this review, the general characteristics of the new AEDs are discussed with regards to their effectiveness, tolerability, drug interaction, safety and mechanisms of action. The effectiveness, of the new AEDs compared with established AEDs is also discussed. Clinical applications of the new AEDs, focusing on gabapentin, topiramate, lamotrigine and levetiracetam are also discussed based on our domestic experience as well as overseas reports.

CACNA1A variants may modify the epileptic phenotype of Dravet syndrome.

Dravet syndrome is an intractable epileptic syndrome beginning in the first year of life. De novo mutations of SCN1A, which encode the Na(v)1.1 neuronal voltage-gated sodium channel, are considered the major cause of Dravet syndrome. In this study, we investigated genetic modifiers of this syndrome. We performed a mutational analysis of all coding exons of CACNA1A in 48 subjects with Dravet syndrome. To assess the effects of CACNA1A variants on the epileptic phenotypes of Dravet syndrome, we compared clinical features in two genotype groups: 1) subjects harboring SCN1A mutations but no CACNA1A variants (n=20) and 2) subjects with SCN1A mutations plus CACNA1A variants (n=20). CACNA1A variants detected in patients were studied using heterologous expression of recombinant human Ca(v)2.1 in HEK 293 cells and whole-cell patch-clamp recording. Nine CACNA1A variants, including six novel ones, were detected in 21 of the 48 subjects (43.8%). Based on the incidence of variants in healthy controls, most of the variants seemed to be common polymorphisms. However, the subjects harboring SCN1A mutations and CACNA1A variants had absence seizures more frequently than the patients with only SCN1A mutations (8/20 vs. 0/20, p=0.002). Moreover, the former group of subjects exhibited earlier onset of seizures and more frequent prolonged seizures before one year of age, compared to the latter group of subjects. The electrophysiological properties of four of the five novel Ca(v)2.1 variants exhibited biophysical changes consistent with gain-of-function. We conclude that CACNA1A variants in some persons with Dravet syndrome may modify the epileptic phenotypes.

Questionnaire-based assessment of behavioral problems in Japanese children with epilepsy.

Behavioral problems in Japanese children with epilepsy were investigated by means of a questionnaire for parents consisting of three checklists: the Child Behavior Checklist (CBCL)/4-18 Japanese Edition, the High-Functioning Autism Spectrum Screening Questionnaire (ASSQ), and the Attention-Deficit/Hyperactivity Disorder (ADHD) Rating Scale-IV (ADHD-RS) for parents. The participants were the parents of 108 children aged 6-18 years with apparently normal intelligence. The CBCL indicated abnormal behavior in 10.5 to 35.6% of the children, and T scores on both the internalizing and externalizing scales had a significant positive relation with scores on the ASSQ and ADHD-RS. It was revealed through multivariate logistic regression analysis that the persistence of seizures was significantly related with abnormality on the externalizing scale of the CBCL (p=0.010, odds ratio: 3.48, 95% confidence interval: 1.34-9.02). Future studies are needed to determine whether seizure freedom improves behavior in children with epilepsy.

Successful treatment of early myoclonic encephalopathy using lidocaine and carbamazepine.

We report two female infants with early myoclonic encephalopathy (EME) whose intractable focal seizures were suppressed with lidocaine and carbamazepine (CBZ). Although EME is a form of early-onset epileptic encephalopathy characterised by myoclonus and focal seizures that are highly resistant to treatment, lidocaine and CBZ may prove effective in treating this disorder. Future studies should be performed in order to determine whether there are common specific mechanisms of seizure generation related to the sodium channel in these patients.

Inhibitory function and working memory in attention deficit/hyperactivity disorder and pervasive developmental disorders: does a continuous cognitive gradient explain ADHD and PDD traits?

To clarify the relationship between attention deficit/hyperactivity disorder (AD/HD) and pervasive developmental disorders (PDD), we investigated the common features and differences of these disorders in neuropsychological profiles. The subjects were 4 groups of Japanese boys aged 6 to 15 years, categorized by diagnosis:AD/HD (n＝20), PDD with comorbid AD/HD (PDD＋:n＝16), PDD without comorbid AD/HD (PDD－:n＝8), and typically developing (n＝60). We evaluated executive function (EF) through verbal and visuospatial memory tasks, the Go/NoGo task, and the color-word matching Stroop task. We performed a categorical analysis to estimate the effects of the 3 disorders on EF and a dimensional analysis to estimate the effects of symptom scales on EF. We found that the AD/HD and PDD＋ subjects had negative effects on verbal working memory and intra-individual response variability. The severity of these impairments was positively correlated with the inattentiveness score. The subjects with a PDD＋ or PDD－ diagnosis had poorer scores on interference control;the severity of this impairment was correlated with the PDD symptom score. Impairments in visuospatial working memory were detected in the AD/HD and PDD－ groups but not in the PDD＋ group. Impairments in inhibition of the pre-potent response were noted in all 3 categories. AD/HD and PDD share neuropsychological features, though each disorder has a specific impairment pattern. Our findings partially support the idea that AD/HD and PDD are on a spectrum.

Cryptogenic West syndrome and subsequent mesial temporal lobe epilepsy.

We report on a male patient who experienced a previously unreported sequence of cryptogenic West syndrome in infancy and subsequent mesial temporal lobe epilepsy. His complex partial seizures were consistently characterised by motionless staring with brief right eye blinking. Scalp electroencephalography (EEG) showed bilateral temporal spikes which were dominant on the right side. Magnetic resonance imaging (MRI) revealed no organic brain lesion. Invasive EEG recording captured seizures with right hippocampal onset. The patient became seizure-free following right temporal lobectomy at 27 years, 8 months of age. Pathological examination of the resected specimen revealed corpora amylacea and gliosis in the temporal cortex but no clear findings of hippocampal sclerosis. It is suggested that an epileptogenic lesion causing MRI-negative mesial temporal lobe epilepsy may give rise to apparent cryptogenic West syndrome in infancy.

Dravet syndrome: a genetic epileptic disorder.

Dravet syndrome (DS), or severe myoclonic epilepsy in infancy, is one of the most severe types of genetic epilepsy. It is characterized by the initial occurrence of febrile or afebrile seizures that often evolve into status epilepticus in infants with normal development, and by the subsequent appearance of myoclonic and/or atypical absence seizures as well as complex partial seizures. The key feature that characterizes DS is fever sensitivity, although photosensitivity and pattern-sensitivity are also often seen. The prognosis is unfavorable in most cases. Seizures become drug-resistant and persist, with many patients suffering from motor and cognitive impairment. Mutations of SCN1A, which encodes the voltage-gated sodium channel NaV1.1, are the most frequent genetic cause of this syndrome. SCN1A mutations and/or microchromosomal rearrangements involving SCN1A are detected in about 85ï½µ of patients. Mutations of PCDH19 have also been reported in female patients with clinical findings compatible with DS. PCDH19 mutations might account for 5ï½µ of overall DS cases. Thirty years after its first description, DS is considered as a model of channelopathy. This survey reviews recent developments in the research literature on DS, focusing on the clinical course, as well as its genetic causes.

Relationships between the color-word matching Stroop task and the Go/NoGo task: toward multifaceted assessment of attention and inhibition abilities of children.

Both selective attention and response inhibition can be assessed through the Stroop task and the Go/NoGo task (Go/NoGo). The color-word matching Stroop task (cwmStroop) differs from the traditional Stroop task in ways that make it easy to administer, and it enables the examiners to analyze reaction time. It is expected that the cwmStroop and Go/NoGo tasks will be useful as clinical assessments for children with developmental disorders and in combination with functional magnetic resonance imaging studies. The objectives of this study were to elucidate the pattern of developmental change in cwmStroop scores and Go/NoGo scores and to determine whether and how cwmStroop scores are related to Go/NoGo scores. The subjects consisted of 108 healthy Japanese children aged 6-14 years. We found that cwmStroop and Go/NoGo scores displayed clear developmental changes between 6 and 14 years of age. The children's scores on the 2 tasks followed different developmental courses, however, and the correlation between scores on the two tasks was weak on the whole. These results indicate that the cwmStroop and Go/NoGo tasks tap different aspects of selective attention and response inhibition. Therefore it is expected that the combination of both tests will be useful in the multifaceted assessment of selective attention and response inhibition in childhood.

[A study of reading disorder comorbid with pervasive developmental disorder or attention-deficit/hyperactivity disorder].

OBJECTIVE: We investigated the frequency and characteristics of reading disorder comorbid with pervasive developmental disorder (PDD) or attention-deficit/hyperactivity disorder (AD/HD). METHODS: Articulation times and reading errors were evaluated using four Japanese reading tasks (a monomoraic syllable reading task, a word reading task, a non-word reading task, and a short sentence reading task) in 31 children with PDD (22 boys and 9 girls) aged 6-14 years (average 9.5 years) and 39 children with AD/HD (33 boys and 6 girls) aged 6-12 years (average 9.6 years). Poor readers (PRs) were identified when articulation times were significantly longer than those of typically-developing children (> or = 2.0 SD) for two or more reading tasks, and non-PRs were identified when articulation times were within normal range (<2.0 SD) for all reading tasks. RESULTS: Eight children with PDD (25.8%) and 17 children with AD/HD (43.6%) were identified as PRs. For 13 of the 70 subjects, the chief complaints were difficulties in reading and writing words at their first visit to our hospital. All 13 of these subjects had AD/HD, and twelve of these were additionally identified as PRs. Among the remaining 26 children with AD/HD, five (19.2%) were identified as PRs. In AD/HD children, PRs made significantly more reading errors and had lower IQ scores than did non-PRs, but in PDDchildren, there were no significant differences between these two groups regarding IQ or reading errors. An analysis using the Clinical-Symptoms-Checklist for Reading and Writing Words revealed that PRs in our study showed difficulties in reading words in daily life. CONCLUSIONS: PRs in our study had reading disorders, which would, in turn, mean that reading disorder was often comorbid with PDD or AD/HD. These results strongly indicate the necessity of testing for the presence of reading disorder in children with PDD or AD/HD.

[Peculiar involuntary movements in premature babies with specific cerebellar injuries].

We observed characteristic involuntary movements in premature babies during early infancy. These movements consisted of asymmetrical irregular banging of the extremities, similar to chorea, ballisms, or jitteriness. We investigated the clinical characteristics and neuroimaging findings of the patients with these peculiar involuntary movements to clarify their pathophysiological mechanisms and to find a treatment. In our sequential follow-up study on 90 premature infants with various pre-and perinatal brain insults, we found various types of cerebellar injuries in 28 patients. In 19 of these, the prominent injuries were observed in the inferior cerebellar hemispheres. These cerebellar injuries were often observed in patients born before the gestational age of 27 weeks. Fourteen of the 28 patients with cerebellar injuries displayed the above-mentioned characteristic involuntary movements. Twelve of these 14 patients with both cerebellar injury and involuntary movements were born before the gestational age of 27 weeks. On the contrary, 10 patients with cerebellar injury born after the gestational age of 27 weeks did not display these peculiar involuntary movements. It is noteworthy that cerebral injuries were not associated with the occurrence of these involuntary movements. Two patients with asymmetrical cerebellar deformity caused by compression due to a cystic lesion did not show these involuntary movements. The movements appeared around the corrected age of 3 months, and they disturbed the patients' acquisition of sitting ability. Nine patients with these involuntary movements developed severe athetotic cerebral palsy. These movements showed drug resistance, however, benzodiazepines had a partial effect in some patients. Recently, cerebellar injury in premature infants has received a lot of attention. We believe that the peculiar involuntary movements we observed in the present patient group may be caused by a particular type of cerebellar damage specific to premature infants born before 27 weeks of gestational age.

High-frequency oscillations in idiopathic partial epilepsy of childhood.

PURPOSE: We explored high-frequency oscillations (HFOs) in scalp sleep electroencephalography (EEG) studies of patients with idiopathic partial epilepsy (IPE) of childhood in order to obtain a better understanding of the pathologic mechanisms underlying IPE. METHODS: The subjects were 45 patients, including 32 with benign childhood epilepsy with centrotemporal spikes (BCECTS) and 13 with Panayiotopoulos syndrome (PS). A total of 136 EEG records were investigated through temporal expansion and filtering of traces and time-frequency spectral analysis. KEY FINDINGS: HFOs with frequency of 93.8-152.3 Hz (mean 126.2 ± 13.6 Hz) in the band of ripples were detected in association with spikes in 97 records (71.3%). Time from last seizure to the EEG recording was significantly shorter in those with spike-related HFOs than in the EEG recordings with spikes without HFOs (p = 0.006). Although time from last seizure reflects age, age at the time of recording was not significantly different between EEG studies with and without HFOs. Peak-power values of the high-frequency spots in time-frequency spectra were significantly negatively correlated with time from last seizure (R(2) = 0.122, p < 0.001) but not with age at the time of recording. Peak frequencies of the high-frequency spectral spots were not significantly correlated with age at the time of recording or with time from last seizure. SIGNIFICANCE: The close relationship between the generation of spike-related HFOs and the period of active seizure occurrence indicated that HFOs may tell us more about epileptogenicity in IPE than the spikes themselves. Because there is a spectrum of pediatric epileptic disorders extending from the benign end of BCECTS to the encephalopathic end of epilepsy with continuous spike-waves during slow-wave sleep (CSWS), and HFOs that have already been detected in association with CSWS were more prominent than HFOs in IPE, intense spike-related HFOs may indicate poor prognosis.

Empirical approach for improved estimation of unbound serum concentrations of valproic acid in epileptic infants by considering their physical development.

The unbound serum concentration of valproic acid (VPA) is closely related to its therapeutic efficacy. In epileptic infants, the unbound VPA concentration varies largely from patient to patient, being difficult to predict using the reported equations for older children. To establish an equation to estimate the unbound concentration in infants, we empirically characterized the relationship between total and unbound VPA concentrations, taking their growth and development into consideration. Data were retrospectively collected from archived clinical records of 30 epileptic infants aged 0-11 months old. The relationship between total and unbound VPA concentrations was analyzed according to the Langmuir equation, in which the patient's body weight, height, and body surface area were considered as physical development indices. Inter- and intra-individual variabilities in the VPA concentrations were also considered. It was shown that the unbound VPA concentration in infants is properly estimated when their body weights are taken into account, in which the parameter for the maximum binding site concentration (Bm) increases as the body weight increases, while that for the dissociation constant (Kd) is unaltered. Additionally, the relationship was shown to slightly change when the infants are concomitantly treated with VPA and the other antiepileptics. These findings provide useful information to adjust the VPA dosage to achieve optimal therapeutic efficacy in epileptic infants.

Bilaterally independent epileptic spasms in a case of Aicardi syndrome.

A girl with Aicardi syndrome was observed to have two distinct types of asymmetric epileptic spasms, as detected by ictal video-EEG recording at three months of age. When the two types of spasm concurred, they showed no mutual interactions based on either clinical or EEG aspects. This observation does not support the hypothesis that the brainstem always plays an initiating role in generating spasms. [Published with video sequences].

Dravet syndrome with an exceptionally good seizure outcome in two adolescents.

We present two children who exhibited the characteristics of Dravet syndrome during infancy and young childhood, with SCN1A mutation, but nevertheless achieved seizure freedom for at least four years during adolescence. These patients had no episodes of convulsive status epilepticus with a duration of more than 30 minutes and their overall favourable seizure outcome may be related to the prevention of convulsive status epilepticus.

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.

[Aggravation of epilepsy by valproate sodium in a child with cryptogenic localization-related epilepsy].

We report a paradoxical effect of valproate sodium (VPA) observed in a 3-year-old girl with cryptogenic localization-related epilepsy. On admission she experienced two types of seizures that were confirmed by ictal EEGs : complex partial seizures (CPSs) originating from the left hemisphere and combined seizures that began with repetitive myoclonic seizures immediately followed by a CPS. These myoclonic seizures did not possess asymmetrical features, but the ictal EEGs showed left-side dominant multiple spike-waves. The patent's interictal EEGs on admission showed left posterior temporal- parietal spikes during wakefulness and frequent diffuse spike-waves during sleep. In the process of introduction and increase in the dosage of VPA, an aggravation of epileptic discharges, especially a dramatic increase in diffuse spike-waves during sleep, was observed. In the same period of time, myoclonic seizures not followed by CPS newly appeared, and there was an increase in the frequency of CPSs and combined seizures. Marked improvement of epileptic discharges, namely the disappearance of diffuse discharges, and complete suppression of all types of seizures were achieved by the introduction of carbamazepine (CBZ) along with the withdrawal of VPA. During the clinical course, the patient did not display any signs or symptoms of VPA encephalitis, overdose of VPA or metabolic aberration. The paradoxical effect of CBZ in localization-related epilepsy is well-known, yet in this case, VPA displayed a similar paradoxical effect. Additionally, CBZ was efficacious in the suppression of secondary bilateral synchrony on EEG and also successfully controlled CPSs, combined seizures and myoclonic seizures.

[Paroxysmal automatic movements mimicking neonatal seizures induced by midazolam].

We have observed paroxysmal automatic movements including drum-beating and pedaling motions in three full-term neonates following intravenous bolus injections (0.1-0.3 mg/kg/dose) or drip infusions (0.2 mg/kg/h) of midazolam used for sedation. In one patient, abnormal movements were also induced by a bolus injection of midazolam during the EEG recording, and no change was revealed in the EEG during the episode. In another patient, abnormal movements were further worsened by an injection of diazepam. Interictal EEGs of all patients were normal. The clinical manifestations of these paroxysmal automatic movements and the mode of their appearance were quite similar in all patients. It is quite likely that abnormal movements in the patient without ictal EEG change do not have epileptic origin but brainstem release phenomenon induced by midazolam. Because the abnormal movements in the other two cases had similar clinical manifestations and mode of appearance, we suspected that these movements were also non-epileptic though ictal EEGs were not recorded in theses cases. When we encounter paroxysmal automatic movements mimicking neonatal seizures following intravenous midazolam administration, ictal EEG recordings are recommended. If there are no ictal changes, we should avoid treatment with anticonvulsant drugs for these movements. Since midazolam is frequently used in neonates for sedation during various examinations, future investigations on the selection of appropriate drugs and dosage for sedation in neonates, including the usage of midazolam, are necessary.

[Lamotrigine add-on therapy for childhood-onset refractory epilepsy: comparison of the efficacy between 3 months and 6 months after initiation].

We investigated the effect of lamotrigine (LTG) add-on therapy in 50 patients with childhood-onset refractory epilepsy (25 males and 25 females): 15 with localization-related epilepsy, 33 with generalized epilepsy, and 2 with undetermined epilepsy. Twenty-four patients had experienced a period of West syndrome during their clinical course. Age at the start of LTG therapy ranged from 2 years 6 months to 41 years 2 months: <16 years in 43 and > or = 16 years in 7. Seizure frequency was > or = 1 per day in 36 patients (72%) and > or = 1 per week in 14 (28%). We increased the LTG dosage every two weeks in accordance with usage recommendations. We evaluated efficacy at two points: 3 and 6 months after the start of LTG. At the 6-month point, seizure freedom was achieved in 2 patients (4%), > or = 50% seizure reduction in 14 (28%), 25 to 50% seizure reduction in 20 (40%), no effect in 6 (12%), and aggravation in 4 (8%). Only 4 patients (8%) stopped LTG therapy within 6 months due to LTG-related mild skin rash in 2 and suspicion of seizure aggravation in the other 2. In terms of seizure types, seizure freedom or > or = 50% seizure reduction was achieved in 29% for epileptic spasms, 32% for tonic seizures, and 29% for partial seizures. A comparison between the 3- and 6-month points revealed that the efficacy level was increased or maintained in 77% of the patients and decreased in 23%. In most cases, the highest level of efficacy appeared within 3 months with doses that were smaller than maintenance doses. Observed CNS-related adverse effects included somnolence in 16 patients, irritability in 14, and sleep disturbance in 11. Positive psychotropic effects in daily activities were seen in 28 patients (56%). These effects appeared regardless of the change in seizure frequency with doses that were smaller than maintenance doses.

[Children with attention deficit/hyperactivity disorder and pervasive developmental disorder:attention and response inhibition in the kiddie continuous performance test].

Continuous Performance Test (CPT) is widely used to assess the attention function and response inhibition in both children and adults. This study attempts to examine the performances of boys with attention deficit/hyperactivity disorder (AD/HD) and pervasive developmental disorder (PDD) with and without comorbid AD/HD using a CPT. Among the various versions of the CPT available, we used the Kiddie CPT (K-CPT) modified for younger children. The K-CPT was administered to children with AD/HD (n=22), those with PDD (n=19), and typically developing children (n=41) from 7 to 12 years of age. All children were drug free at the time of examination. The performances were examined in 6 measures:total number of omission errors (OE), total number of commission errors (CE), mean hit reaction time (HRT), hit reaction time standard error (HRTSE), perceptual sensitivity (d'), and response style (beta). Significantly lower scores in d' and a tendency to more errors in CE were found in the AD/HD group compared with the control group. Significantly lower scores in d' and significantly more errors in CE were also found in the PDD group with AD/HD symptoms compared with the control group. Moreover the AD/HD group showed significantly more errors in OE and higher scores in HRTSE compared with the control group. There were no significant group differences between the PDD group without AD/HD symptoms and the control group on all measures. Less favorable scores in AD/HD suggest inadequate selective attention, sustained attention and/or response inhibition. Results of the PDD group with comorbid AD/HD may reflect a basis of AD/HD impairment. Our findings may provide an understanding of neuropsychological characteristics underlying developmental disorders.