Electrophysiological study of face inversion effects in Williams syndrome

Objective: In order to evaluate whether face perception is intact or not in Williams syndrome (WS), the face inversion effects (FIE) in the event-related potential (ERP) or magnetoencephalography (MEG) were investigated in three teenaged patients with WS. Methods: Responses to the inverted faces and upright faces were compared using MEG for one 13 year old girl with WS (subject A) and ERP for boys with WS at 16 and 14 years of age (subjects B and C, respectively). Results: Although age-matched control children showed FIE in both MEG and ERP studies, two subjects (A and B) with WS showed no FIE at all. The neurophysiological data of ERP in subject B was significantly different from those of the age-matched controls. On the other hand, a boy with WS (subject C) showed typical FIE in the same manner as the age-matched controls. Conclusions: The difference between those with or without FIE was not explained merely by the chronological age, a simple delay in mental age or in the ability to discriminate among upright faces. The absence of FIE may be related to the severity of a deficit in the dorsal pathway function that is characteristic to the syndrome.     

Modification by the genes ALAD and VDR of lead-induced cognitive effects in children

Lead has negative effect on cognitive functions in children. However, individuals differ in susceptibility. One possible explanation is a genetic predisposition. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD) and the vitamin D receptor (VDR) genes may modify lead metabolism and neurotoxicity, but information regarding the central nervous system is very limited. The aim of the study was to determine whether ALAD and VDR polymorphisms modify blood lead (B-Pb), and the association between B-Pb and cognitive function (IQ) in children. In 2007-2010 a cohort of 175 children (age 6-10 years, mean 7.8) was recruited in Southern Poland, tested for IQ (Wechsler intelligence scale) and analyzed for B-Pb (range 9.0-221; mean 46.6 μg/L), ALAD (RsaI, MspI) and VDR (FokI, BsmI, TaqI) polymorphisms. ALAD or VDR genotypes were not associated with B-Pb. B-Pb was non-significantly negatively associated with full scale IQ (r_S = −0.11; P = 0.14), and significantly with performance subscale results (r_S = −0.19; P = 0.01). The ALAD RsaI polymorphism modified the relationship between full scale IQ and B-Pb: RsaI T carriers had a steeper slope compared to CC homozygote carriers (β coefficient −0.06 vs 0.32, respectively, P for interaction <0.001, adjusted for the child's age, mother's education and family income). This means that with increasing B-Pb with 1 μg/L, T carriers demonstrate 0.06 score lower IQ. For the VDR BsmI, B carriers had a steeper slope than the bb homozygotes carriers (β coefficient −0.08 vs 0.16, respectively, P for interaction = 0.001), and similar effect was found for TaqI t carriers vs TT homozygotes (P for interaction = 0.02). For ALAD MspI and VDR FokI there was no significant modification. The ALAD RsaI, VDR BsmI and TaqI polymorphisms modified the relationship between IQ and B-Pb. Hence, there is a fraction of the population, which is particularly sensitive to lead neurotoxicity.     

Patterns of cerebral white matter damage and cognitive impairment in adolescents born very preterm

There is increasing evidence about the presence of white matter damage in subjects with a history of premature birth, even in those classified as good outcome because of an apparently normal development. Although intellectual performance is within normal limits in premature children it is significantly decreased compared to paired controls. The purpose of this study was to investigate the relationship between a lower performance intelligence quotient and white matter damage in preterm adolescents. The sample comprised 44 adolescents (mean age ± S.D.: 14.4 ± 1.6 years) born before 32 weeks of gestational age and 43 term-born adolescents (14.5 ± 2.1 years). Individual voxel-based morphometry analyses demonstrated that 35/44 (80%) preterm subjects had white matter abnormalities. The centrum semiovale and the posterior periventricular regions were the most frequently affected areas. Correlation analysis showed that in preterms the performance intelligence quotient correlated with the whole-brain white matter volume (r = 0.32; P = 0.036) but not with grey matter volume. Complementary analysis showed that low scores in the Digit Symbol subtest, a measure of processing speed, in the preterm group correlated with reductions in white matter concentration. These results suggest that white matter damage is highly common and that it persists until adolescence. Hence, diffuse white matter loss may be responsible for performance intelligence quotient and processing speed decrements in subjects with very preterm birth.     

Serial changes of prefrontal lobe growth in the patients with benign childhood epilepsy with centrotemporal spikes presenting with cognitive impairments/behavioral problems

Several studies have reported a higher incidence of learning and behavioral difficulties in association with frontal lobe dysfunctions in children with benign childhood epilepsy with centrotemporal spikes (BCECTS). We studied serial changes in frontal and prefrontal lobe volumes using three-dimensional magnetic resonance imaging in BCECTS with or without cognitive impairments and behavioral problems and evaluated correlations between prefrontal lobe growth and active seizure period. Serial changes in regional cerebral volumes were measured in two patients with cognitive impairments and behavioral problems (BCECTS(+)) and five patients without neuropsychiatric deficits (BCECTS(−)). Eleven normal subjects (4-13 years old) served as controls. Volumes of the frontal and prefrontal lobes were determined using a workstation, and the prefrontal-to-frontal lobe volume ratio was calculated. Frontal and prefrontal lobe volumes revealed growth disturbance in BCECTS(+) compared with BCECTS(−) and control subjects. In addition, prefrontal-to-frontal lobe volume ratio increased serially in BCECTS(−) similarly to controls, but was stagnant or decreased in BCECTS(+). Prefrontal growth also revealed more rapid recovery in a BCECTS(+) patient with shorter active seizure period. These findings suggest that longer active seizure period as frequent spike-waves coupled with the occurrence of frequent seizures may be associated with prefrontal lobe growth disturbance, which relates to neuropsychological problems.     

Outcomes of epilepsy surgery in childhood-onset epileptic encephalopathy

Purpose: to evaluate the outcomes and role of epilepsy surgery in children with intractable epileptic encephalopathy (EE). Methods: ninety-five children (64 boys, 31 girls) with intractable EE were treated by epilepsy surgery at Severance Children’s Hospital from 2003 to 2008. Surgical treatments included lobar resection, hemispherotomy and corpus callosotomy (CC). Seventy-six children were Lennox–Gastaut syndrome (LGS), and 19 had West syndrome. Results: of the 76 patients with LGS, CC was performed in 37 patients (48.7%), lobar resection in 29 (38.2%) and hemispherotomy in 10 (13.2%). Of the 19 patients with West syndrome, respective surgery was performed in 15 patients (78.9%) and CC in 4 (21.1%). Of the patients receiving respective surgery, Engel’s class I outcomes were achieved for 24 of 39 (61.5%) of LGS patients, and for 9 of 15 (60.0%) of West syndrome. Malformations of cortical development were commonly observed, appearing in 73.5% (36/49). In neuropsychiatric tests, 19 of 27 with LGS demonstrated improvement in postoperative cognitive function. More significant intellectual improvement correlated well with shorter epilepsy duration, good seizure outcomes, and decreased number of antiepileptic drugs. Conclusions: epilepsy surgery should be considered in treating childhood intractable EE with expectation of improvement of both seizure and cognitive outcomes, even in cases of LGS.     

The relationship between gross motor function impairment in cerebral palsy and sleeping issues of children and caregivers

AimTo investigate, among children and adolescents with cerebral palsy (CP), the relationship between impairment of the gross motor function and: (i) child sleep disorders; (ii) the need for nocturnal support; and (iii) the quality of sleep of their caregivers.MethodsFor children, we considered their scores on the gross motor function measure (GMFM-88) and on the sleep disturbance scale for children (SDSC), besides analyzing qualitative features about their sleep. For caregivers, we considered their scores in the Pittsburgh sleep quality index (PSQI).ResultsOur sample was comprised of 87 participants with mean age of 11.4 years old (±3.4). We observed correlations between GMFM-88 and disorders of initiating and maintaining sleep (DIMS) (r = −0.22; p = 0.039), sleep–wake transition disorders (SWTD) (r = 0.26; p = 0.017) and disorders of arousal (DA) (r = 0.23; p = 0.033). Children receiving nocturnal support presented lower scores in the GMFM-88 (p = 0.001) and higher scores in the SDSC (p = 0.029). For the caregivers, we found no correlation between GMFM-88 and PSQI. Nonetheless, their PSQI scores correlated with the SDSC scores (r = 0.24; p = 0.027).ConclusionImpairment of the gross motor function correlated with DIMS and the need for nocturnal support but might not have an impact on the caregivers’ sleep, which in turn correlated with child sleep disorders.