Visual and spatial long-term memory: differential pattern of impairments in Williams and Down syndromes

This purpose of this study was to investigate visual-object and visual-spatial long-term memory (LTM) abilities in individuals with Williams syndrome (WS) and Down syndrome (DS). Four groups comprised of 15 participants were included: WS group (10 males) with a mean chronological age (CA) of 18 years 5 months, SD 6 years 4 months, and mean mental age (MA) of 6 years 8 months, SD 1 year 5 months; WS control group (eight males) comprised of typically developing children (CA mean 6y 7mo, SD 8mo); DS group, (10 males, CA mean 16y 5mo, SD 5y 10mo; MA mean 5y 4mo, SD 8mo); and DS control group (seven males) formed by typically developing children (CA mean 5y 6mo, SD 7mo). In the WS and DS groups mental age and IQ were evaluated with the Form L-M of the Stanford-Binet Intelligence Scale. Results showed that individuals with WS showed decreased learning of visual-spatial material but substantially typical learning of visual-object patterns as compared to a group of mental-age-matched typically developing children. Individuals with DS showed the opposite profile, i.e. typical learning of visual-spatial sequences but impaired learning of visual-object patterns. These results, showing an interesting double dissociation between these two genetic syndromes in the learning of visual-object patterns as opposed to visual-spatial data, support the interpretation of learning disability* as a heterogeneous condition, characterized by potentially very different qualitative profiles of cognitive impairment.     

Visual and spatial working memory dissociation: evidence from Williams syndrome

This study aimed at investigating the possible dissociation between visual and spatial working memory (WM) by means of two different experiments. In the first experiment, a WM test for visual material and for spatial information was given to a group of 202 normally developing children (chronological age 7 years 5 months, SD 1.6 years; 109 males, 93 females). Results document a different developmental trend in the two span tests. In the second experiment, we presented the same visual and spatial WM tests to a group of 13 individuals with Williams syndrome (WS), seven males and six females (chronological age mean 18 years 3 months, SD 5.1; mental age mean 7 years 2 months, SD 1.5 years), and to a control group of 26 typically developing children 14 males and 12 females matched for mental age (mean 7 years 2 months, SD 1.4). The results of this second experiment show that, on average, the spatial span obtained by individuals with WS was significantly lower than control participants, but visual span was comparable in the two groups. Our data support the hypothesis of a dissociation within the visuo-spatial sketch pad slave system in the WM model.     

Short-term memory and vocabulary development in children with Down syndrome and children with specific language impairment

A longitudinal comparison was made between development of verbal and visuo-spatial short-term memory and vocabulary in children with Down syndrome (DS), children with specific language impairment (SLI), and typically developing children as a control group. Participants were 12 children with DS (6 males, 6 females; mean chronological age 9y 9mo [SD 2.8 mo], range 8y 6mo to 11y 4mo); nine children with SLI (4 males, 5 females; mean chronological age 3y 9mo [SD 4.8mo], range 3y 3mo to 4y 5mo); and 12 typically developing children (5 males, 7 females; mean chronological age 4y 4mo [SD 3.9mo], range 3y 3mo to 4y 3mo). Participants were matched on mental age (mean mental age 4y 3mo). All participants completed verbal short-term memory, visuo-spatial short-term memory, and expressive and receptive vocabulary tasks on three occasions over 1 year. Similarities were seen in the clinical groups for verbal short-term memory. There was some evidence of difficulty in visuo-spatial short-term memory in the children with SLI relative to the other groups, but all three groups showed overlap in visuo-spatial short-term memory performance. At the final time-point vocabulary performance in the clinical groups was similar; the typically developing children showed higher vocabulary abilities than both clinical groups.     

Reduced parietal and visual cortical activation during global processing in Williams syndrome

Several lines of investigation suggest that individuals with Williams syndrome (WS), a neurodevelopmental disorder of well-characterized genetic etiology, have selective impairments in integrating local image elements into global configurations. We compared global processing abilities in 10 clinically and genetically diagnosed participants with WS (eight females, two males; mean age 31y 10mo [SD 9y 7mo], range 15y 5mo-48y 4mo) with a typically developed (TD) age- and sex-matched comparison group (seven females, one male; mean age 35y 2mo [SD 10y 10mo], range 24y-54y 7mo) using functional magnetic resonance imaging (fMRI). Behavioral data showed participants with WS to be significantly less accurate (p<0.042) together with a non-significant trend to be slower than the TD comparison group while performing the global processing task. fMRI data showed participants with WS to possess reduced activation in the visual and parietal cortices. Participants with WS also showed relatively normal activation in the ventral occipitotemporal cortex, but elevated activation in several posterior thalamic nuclei. These preliminary results largely confirm previous research findings and neural models implicating neurodevelopmental abnormalities in extended subcortical and cortical visual systems in WS, most notably dorsal-stream pathways.     

Refractive errors in infancy predict reduced performance on the movement assessment battery for children at 3 1/2 and 5 1/2 years

We have previously reported that significant hyperopia at 9 months predicts mild deficits on visuocognitive and visuomotor measures between 2 years and 5 years 6 months. Here we compare the motor skills of children who had been hyperopic in infancy (hyperopic group) with those who had been emmetropic (control group), using the Movement Assessment Battery for Children (Movement ABC). Children were tested at 3 years 6 months (hyperopic group: 47 males, 63 females, mean age 3 y 7 mo, SD 1.6 mo; control group: 61 males, 70 females, mean age 3 y 7 mo, SD 1.2 mo) and at 5 years 6 months (hyperopic group: 43 males, 56 females, mean age 5 y 4 mo, SD 1.7 mo; control group: 51 males, 62 females, mean age 5 y 3 mo, SD 1.6 mo). The hyperopic group performed significantly worse at both ages, overall and on at least one test from each category of motor skill (manual dexterity, balance, and ball skills). Distributions of scores showed that these differences were not due to poor performance by a minority but to a widespread mild deficit in the hyperopic group. This study also provides the first normative data on the Movement ABC for children below 4 years of age, and shows that it provides a useful measure of motor development at this young age.     

Increased gyrification in Williams syndrome: evidence using 3D MRI methods

Understanding patterns of gyrification in neurogenetic disorders helps to uncover the neurodevelopmental etiology underlying behavioral phenotypes. This is particularly true in Williams syndrome (WS), a condition caused by de novo deletion of approximately 1 to 2 Mb in the 7q11.23 region. Individuals with WS characteristically possess an unusual dissociation between deficits in visual-spatial ability and relative preservations in language, music, and social drive. A preliminary postmortem study reported anomalous gyri and sulci in individuals with WS. The present study examined gyrification patterns in 17 participants with WS (10 females, 7 males; mean age 28 years 11 months, SD 8 years 6 months) and 17 age- and sex-matched typically developing control participants (mean age 29 years 1 month, SD 8 years 1 month) using new automated techniques in MRI. Significantly increased cortical gyrification was found globally with abnormalities being more marked in the right parietal (p=0.0227), right occipital (p=0.0249), and left frontal (p=0.0086) regions. These results suggest that one or more genes in the 7q11.23 region are involved during the critical period when cortical folding occurs, and may be related to the hypothesized dorsal/ventral dissociation in this condition.     

Dopaminergic modulation of visual-spatial working memory in Parkinson's disease

Visual-spatial working memory (WM) impairment is frequently associated with the early stage of Parkinson's disease (PD). The aim of this study was to evaluate the performance of a group of PD patients in visual-spatial and visual-object WM tasks and to investigate the effect of administering the dopaminergic agonist apomorphine (experiment 1) or the dopamine precursor L-dopa (experiment 2) on the performance of tests assessing these functions. To study WM processes, the PD patients and age-matched normal controls were given an n-back task paradigm. In both experiments, the PD patients were submitted to two evaluations: one after a 12-hour therapy washout and the other 15 min after a subcutaneous infusion of apomorphine (average 0.04 mg/kg) or 20/30 min after L-dopa intake (200 mg p.o.). The apomorphine infusion had a worsening effect on reaction times in both visual-spatial and visual-object WM tasks, but it did not influence performance accuracy. Instead, L-dopa administration had a ameliorative effect on accuracy and reaction times in both visual-spatial and visual-object tasks. These results highlight the role of dopamine in the modulation of the WM function in PD patients.     

Patterns of syntactic development in children with Williams syndrome and Down's syndrome: evidence from passives and wh-questions

This study investigates the syntactic abilities of ten individuals with Williams syndrome (WS) (mean chronological age: 8;9 years; mean mental age: 4;8 years) and Down's syndrome (DS) (mean chronological age: 8;7 years; mean mental age: 4;6 years), matched individually on chronological age, mental age and performance IQ. The syntactic components investigated include the comprehension of passives and the production, comprehension and repetition of wh-questions. Performance is compared to ten younger typically developing (TD) controls matched individually to both experimental groups on mental age (mean chronological age: 4;4 years; mean mental age: 5;0 years). Participants were given a standardized measure of grammatical ability and non-standardized tasks exploring the comprehension of active and passive sentences, and the production, comprehension and repetition of a range of wh-question types: wh-subject, wh-object, which NP-subject and which NP-object. Participants with WS and DS performed similarly on the standardized measure of grammatical ability, as well as on the experimental tasks that tapped comprehension of passives, and production and comprehension of wh-questions. Participants with DS performed significantly more poorly than both the WS cohort and TD controls on the repetition of wh-questions. Both the WS and DS cohorts performed significantly more poorly on most of the syntactic tasks compared to the younger TD controls. Individuals with WS and DS experienced significant difficulties in tasks measuring aspects of syntactic ability and performed more poorly than mental age-matched TD controls. Implications of these findings, with regards to the debates around language "intactness" in WS, as well as the similarities and differences in language abilities in WS and DS, dependent on age and developmental stages studied, are explored.     

A 21-week bone deposition promoting exercise programme increases bone mass in young people with Down syndrome

Aim To determine whether the bone mass of young people with Down syndrome may increase, following a 21‐week conditioning training programme including plyometric jumps. Method Twenty‐eight participants with Down syndrome (13 females, 15 males) aged 10 to 19 years were divided into exercise (DS‐E; n=14; eight females, six males mean age 13y 8mo, SD 2y 6mo) and non‐exercise (DS‐NE; n=14; five females, nine males mean age 15y 5mo, SD 2y 6mo) groups. Total and regional (hip and lumbar spine [L1–L4]) bone mineral content (BMC) and total lean mass were assessed by dual energy X‐ray absorptiometry at baseline and after a 25‐minute training session performed twice a week. Repeated‐measures analyses of variation were applied to test differences between pre‐ and posttraining values for BMC and total lean mass. Differences between increments were studied with the Student’s t‐test. Linear regression models were fitted to test independent relationships. Results After the intervention, higher increments in total and hip BMC, and total lean mass, were observed in the DS‐E group (all p<0.05). A time×exercise interaction was found for total lean mass (p<0.05). The increment in total lean mass, height, and Tanner stage accounted for almost for 60% in the increment in total BMC in the DS‐NE group (p<0.05). Interpretation Twenty‐one weeks of training have a positive effect on the acquisition of bone mass in young people with Down syndrome.     

Patterns of syntactic development in children with Williams syndrome and Down's syndrome: Evidence from passives and wh‐questions

This study investigates the syntactic abilities of ten individuals with Williams syndrome (WS) (mean chronological age: 8;9 years; mean mental age: 4;8 years) and Down's syndrome (DS) (mean chronological age: 8;7 years; mean mental age: 4;6 years), matched individually on chronological age, mental age and performance IQ. The syntactic components investigated include the comprehension of passives and the production, comprehension and repetition of wh‐questions. Performance is compared to ten younger typically developing (TD) controls matched individually to both experimental groups on mental age (mean chronological age: 4;4 years; mean mental age: 5;0 years). Participants were given a standardized measure of grammatical ability and non‐standardized tasks exploring the comprehension of active and passive sentences, and the production, comprehension and repetition of a range of wh‐question types: wh‐subject, wh‐object, which NP‐subject and which NP‐object. Participants with WS and DS performed similarly on the standardized measure of grammatical ability, as well as on the experimental tasks that tapped comprehension of passives, and production and comprehension of wh‐questions. Participants with DS performed significantly more poorly than both the WS cohort and TD controls on the repetition of wh‐questions. Both the WS and DS cohorts performed significantly more poorly on most of the syntactic tasks compared to the younger TD controls. Individuals with WS and DS experienced significant difficulties in tasks measuring aspects of syntactic ability and performed more poorly than mental age‐matched TD controls. Implications of these findings, with regards to the debates around language “intactness” in WS, as well as the similarities and differences in language abilities in WS and DS, dependent on age and developmental stages studied, are explored.     

Cognitive outcome following unilateral arterial ischaemic stroke in childhood: effects of age at stroke and lesion location

Aim Plasticity in the developing brain is a controversial issue. Although language and motor function often recover remarkably well following early brain injury, recent evidence suggests that damage to the developing brain results in significant long‐term neuropsychological impairment. Our aim was to investigate the relationship among age at injury, lesion location and intellectual outcome. Method Using age‐appropriate Wechsler scales of intellectual ability, we explored this issue by evaluating a large group (n=145) of children (89 males, 56 females) who experienced unilateral arterial ischaemic stroke during the perinatal period (diagnosed mean 73d, SD 29d), between the ages of 1 month and 5 years (mean 2y 10mo, SD 1y 9mo), or between the ages of 6 and 16 years (mean 11y 1mo SD 3y 6mo). The mean age at assessment was 8 years (SD 3y 10mo) in the perinatal group, 7 years 5 months (SD 2y 9mo) in the 1 month to 5 years group, and 12 years 5 months (SD 3y 9mo) in the 6 to 16 years group. The mean time interval between stroke and assessment was 8 years (SD 18d) for perinatal, 4 years 6 months (SD 1y 5mo) for 1 month to 5 years, and 1 year 4 months (SD 2y 9mo) for 6 to 16 years. The relationship between age at stroke and lesion location (subcortical, cortical, or combined) as it pertains to cognitive outcome was also examined. Results Measures of overall intelligence, verbal ability, working memory, and processing speed were significantly lower in children who had had a stroke than in the normative sample (all z>2.5, all p<0.01). The perinatal group performed more poorly than the other two groups on most cognitive measures, regardless of lesion location. The combined lesion location group performed more poorly than those with damage to either cortical or subcortical areas alone. Further investigation revealed different periods of peak vulnerability for subcortical lesions (perinatal) and cortical lesions (1mo–5y). Interpretation Lesion location modulates the relationship between age at stroke and cognitive outcome.     

Exploring effects of different treadmill interventions on walking onset and gait patterns in infants with Down syndrome

Two cohorts of participants were included to investigate the effects of different treadmill interventions on walking onset and gait patterns in infants with Down syndrome (DS). The first cohort included 30 infants with DS (17 males, 13 females; mean age 10 mo [SD 1.9 mo]) who were randomly assigned to either a lower-intensity-generalized (LG) training group, or a higher-intensity-individualized (HI) training group. A control (C) group from another study, who did not receive treadmill training, served as the control (eight males, seven females; mean age 10.4 mo [SD 2.2 mo]). Mean age at walking onset was 19.2, 21.4, and 23.9 months for the HI, LG, and C groups respectively. At walking onset the HI group was significantly younger than the C group (p=0.011). At the gait follow-up that was conducted between 1 and 3 months after walking onset, three groups significantly different in overall gait patterns (p=0.037) were examined by six basic gait parameters including average velocity, stride length, step width, stride time, stance time, and dynamic base. Post-hoc analyses demonstrated that stride length was the gait parameter largely contributing to this overall group difference (p=0.033), and the HI group produced a significantly longer stride length than the C group (p=0.030). In conclusion, the HI treadmill intervention significantly promoted earlier walking onset and elicited more advanced gait patterns (particularly in stride length) in infants with DS.     

Gross motor functional abilities in preterm-born children with cerebral palsy due to periventricular leukomalacia

To describe the impact of periventricular leukomalacia (PVL) on gross motor function, data on 59 children (37 males, 22 females) with a gestational age (GA) of 34 weeks or less with cerebral palsy (CP) due to PVL grade I (n=20), II (n=13), III (n=25), and IV (n=1) were studied; (mean GA 29 wk 4d [SD 4 wk 6d]; mean birthweight 1318 g [SD 342]). Two independent raters used the Gross Motor Function Classification System (GMFCS) at four time points: T1, mean corrected age (CA) 9 months 15 days (SD 2 mo 6d); T2, mean CA 16 months (SD 1 mo 27 d); T3, mean CA 24 months 27 days (SD 2 mo 3d); and T4, median age 7 years 6 months (range 2 y 2 mo-16 y 8 mo). Interrater reliability and stability across time with respect to the total cohort were kappa>or=0.86 and rho>or=0.74 respectively. The association between PVL and gross motor outcome at T4 was strong (positive and negative predictive values 0.92 and 0.85 respectively). The proportion of children who remained in the same GMFCS level increased from 27% (T1-T4) to 53% (T2-T4) and 72% (T3-T4). PVL grade I to II, as diagnosed in the neonatal period, has a better functional mobility prognosis than PVL grade III-IV. These findings have implications for habilitation counselling and intervention strategies.     

Deficient coordination of associated postural adjustments during a lifting task in children with neurodevelopmental disorders

Precision grip and concomitant anticipatory postural adjustments were investigated in 11 children (three females, eight males; mean age 9 years 1 month, SD 11 months) with attention-deficit-hyperactivity disorder (ADHD); 12 children (three females, nine males; mean age 9 years, SD 7 months) with developmental coordination disorder (DCD), and 13 children (two females, 11 males; mean age 9 years 9 months, SD 11 months) with a combination of ADHD and DCD (ADHD+). There were two comparison groups: an age-matched group (four females, 11 males; mean age 9 years 1 month, SD 14 months) and a younger age group (five females, six males; mean age 6 years 5 months, SD 8 months). Adaptation to different weights was evaluated by lifting a specialized grip instrument monitoring grip force, load force, and centre of foot pressure displacements. Children with ADHD+ showed: (1) excessive grip forces, (2) decreased amplitude and prolonged onset of postural adjustments, and (3) reduced ability to adapt the motor output. Children with ADHD and DCD did not scale manual and postural forces in amplitude and time domains. Children with DCD also differed in delayed timing of postural adjustments. Results indicate that children with ADHD and DCD show a spectrum of neural dysfunctions underlying poor motor coordination, which are not specific to the clinical disorder.     

Motor function following multilevel botulinum toxin type A treatment in children with cerebral palsy

This study evaluated the effects of multilevel botulinum toxin type A (BTX-A) treatments on the gait pattern of children with spastic cerebral palsy (Gross Motor Function Classification System Levels I-III). In this nested case-control design, 30 children (mean age 6y 11mo [SD 1y 5mo]; 21 males, nine females; 19 with hemiplegia, 11 with diplegia) were treated according to best practice guidelines in paediatric orthopaedics, including BTX-A injections. A matched control group of 30 children (mean age 7y 8mo [SD 1y 10mo]; 13 males, 17 females; 19 with hemiplegia, 11 with diplegia) were treated identically, but without BTX-A. Motor development status at 5 to 10 years of age was assessed by means of three-dimensional gait analysis at a mean time of 1 year 10 months (SD 10mo) after the last BTX-A treatment. The control group showed a significantly more pronounced pathological gait pattern than the BTX-A group. Major differences were found for pelvic anterior tilt, maximum hip and knee extension, and internal hip rotation. These results provide evidence for a prolonged effect of BTX-A and suggest that BTX-A injections, in combination with common conservative treatment options, result in a gait pattern that is less defined by secondary problems (e.g. bony deformities) at 5 to 10 years of age, minimizing the need for complex surgery at a later age and enhancing quality of life.     

Neuropsychological profile of Italians with Williams syndrome: an example of a dissociation between language and cognition?

Important claims have been made regarding the contrasting profiles of linguistic and cognitive performance observed in two genetically based syndromes, Williams syndrome (WS) and Down syndrome (DS). Earlier studies suggested a double dissociation, with language better preserved than nonverbal cognition in children and adults with WS, and an opposite profile in children and adults with DS. More recent studies show that this initial characterization was too simple, and that qualitatively different patterns of deficit observed within both language and visual-spatial cognition, in both groups. In the present study, large samples of children and adolescents with WS and age-matched DS are compared with typically developing (TD) controls matched to WS in mental age, on receptive and expressive lexical and grammatical abilities, semantic and phonological fluency, digit span and nonverbal visual-spatial span, and on 2 visual-spatial construction tasks. Study 1 confirmed distinct profiles of sparing and impairment for the 2 groups, within as well as between language and nonlinguistic domains, even after IQ variations were controlled. In Study 2 we compared performance of the children, adolescents and young adults with DS and WS included in the first study, divided on the basis of the chronological age of the participants (under 8 years; over 12 years). Although it is important to stress that these are cross-sectional rather than longitudinal data, the results demonstrated that the profile of younger children is different in respect to those of the older children; initial states of the system cannot be inferred by the final state. Possible neural substrates for these profiles and trajectories are discussed.     

Assessment of cognitive and adaptive behaviour among individuals with congenital insensitivity to pain and anhidrosis

Aim Individuals with congenital insensitivity to pain with anhidrosis (CIPA) are reported to have mental retardation* but to our knowledge no detailed study on the subject has ever been published. The present study assessed and documented cognitive and adaptive behaviour among Arab Bedouin children with CIPA. Methods Twenty‐three Arab Bedouin children (12 females, 11 males) with CIPA aged between 3 and 17 years (mean 9y 7mo, SD 4y 2mo) were assessed. They were compared with 19 healthy siblings of the affected children aged between 5 and 13 years (mean 8y 11mo, SD 2y 10m). All of the children in the comparison group, but only half of the CIPA group, were attending school. The children were evaluated using a standardized, non‐verbal intelligence test, the Leiter International Performance Scale – Revised, and an adaptive behaviour questionnaire, the Vineland Adaptive Behaviour Scales, 2nd edition. Results Based on scores on the intelligence test and the adaptive behaviour scale, children with CIPA functioned in the mental retardation range (mean IQ scores: CIPA group 53.8, comparison group 83.32 [p<0.001]; adaptive behaviour: CIPA group 68.1, comparison group 104.88 [p<0.001]). IQ was significantly higher among the children with CIPA aged up to 7 years 11 months than among the older children 73.83 vs 45.21 (p<0.001). Interpretation As a group, the younger children with CIPA may be functioning above the mental retardation range. We propose that early intervention addressing these children’s needs and developing an appropriate educational system, might improve their outcome.     

Developmental coordination disorder,sex, and activity deficit over time: a longitudinal analysis of participation trajectories in children with and without coordination difficulties

Aim Children with developmental coordination disorder (DCD) are known to participate in active play less than typically developing children. However, it is not known whether the activity deficit between children with and without DCD widens or diminishes over time. Method Data were obtained from a large, prospective cohort study of children (baseline n=2278, total n=2470). Motor coordination was assessed for 2083 students using the short form of the Bruininks–Oseretsky Test of Motor Proficiency. Participation in organized and free‐play activities was assessed using a participation questionnaire on five occasions over 3 years. Mixed‐effects modelling was used to examine differences in participation over time between children with probable DCD (pDCD, n=111, 46 males, 65 females) and their typically developing peers (n=1972, 1016 males, 956 females). The mean age for the whole sample was 9 years 11 months (SD 5mo) at assessment 1, 10 years 5 months (SD 5mo) at assessment 2, 10 years 11 months (SD 5mo) at assessment 3, 11 years 4 months (SD 4mo) at assessment 4, and 11 years 11 months (SD 4mo) at assessment 5. Results Children with pDCD reported less participation in organized and free‐play activities than their typically developing peers, and these differences persisted over time. Among males, the gap in participation in free‐play activities between those with DCD and typically developing children diminished substantially over time; among females, it increased slightly. Interpretation DCD is associated with a persistent activity deficit in children. Its effect on participation appears to be particularly serious among females but may diminish with time among males.     

Congenital heart disease affects local gyrification in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.2DS) is a common genetic condition associated with cognitive and learning impairments. In this study, we applied a three-dimensional method for quantifying gyrification at thousands of points over the cortical surface to imaging data from 44 children, adolescents, and young adults with 22q11.2DS (17 males, 27 females; mean age 17y 2mo [SD 9y 1mo], range 6–37y), and 53 healthy participants (21 males, 32 females; mean age 15y 4mo [SD 8y 6mo]; range 6–40y). Several clusters of reduced gyrification were observed, further substantiating the pattern of cerebral alterations presented by children with the syndrome. Comparisons within 22q11.2DS demonstrated an effect of congenital heart disease (CHD) on cortical gyrification, with reduced gyrification at the parieto-temporo-occipital junction in patients with CHD, as compared with patients without CHD. Reductions in gyrification can resemble mild polymicrogyria, suggesting early abnormal neuronal proliferation or migration and providing support for an effect of hemodynamic factors on brain development in 22q11.2DS. The results also shed light on the pathophysiology of acquired brain injury in other populations with CHD.     

Cognitive functions in classic phenylketonuria and mild hyperphenylalaninaemia: experience in a paediatric population

A study of 37 individuals with phenylketonuria (PKU; 17 females and 20 males, mean age 9y 9mo (standard deviation [SD] 5y 3mo), range 2y 8mo to 19y 4mo; and 35 individuals with hyperphenylalaninaemia (HPA; 20 females, 15 males, mean age 7y 10mo [SD 3y 2mo], range 2y 8mo to 17y 3mo) compared with 29 healthy controls (14 females and 15 males, mean age 9y 8mo [SD 4y 9mo], range 2y 6mo to 18y 10mo) was performed. The aim was to assess cognitive function in persons with HPA and to investigate the relation between cognitive function in PKU and the metabolic control of patients. A wide variety of neuropsychological tests was employed. Those with PKU showed lower values in intelligence and in visuo-spatial, fine motor, executive, and attention functions when compared with a control population. Plasma phenylalanine values from the first 6 years of life were negatively associated with intelligence and other cognitive functions. Executive function scores were significantly lower when comparing HPA patients with the control group. It was concluded that individuals with PKU under dietary treatment may present slightly decreased cognitive function scores when compared with control individuals, while those with HPA have scores mostly similar to those of controls, except for executive function tests. Good metabolic control of PKU seems necessary to prevent cognitive function impairments, especially during the first 6 years of life.