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.     

Evidence from two genetic syndromes for the independence of spatial and visual working memory

This study aimed at investigating the possible dissociation between visual-object and visual-spatial working memory (WM) in individuals with Williams syndrome (WS) and Down syndrome (DS). Four study groups were included: WS group (10 males, 5 females) with a mean chronological age (CA) of 19 years 8 months (SD 6y 1mo) and a mean mental age (MA)of 6 years 11 months (SD 1y 5mo); WS comparison group (7 males, 8 females) comprised of typically developing children with a mean CA of 6 years 10 months (SD 10mo) and a mean MA of 6 years 11 months (SD 8mo)matched as a group with the participants with WS on the basis of mental age; DS group (11 males, 7 females) with a mean CA of 15 years 10 months (SD 5y 8mo) and a mean MA of 5 years 2 months (SD 8mo); and DS comparison group (10 males, 8 females) with a mean CA of 5 years and 1 month (SD 7mo)and a mean MA of 5 years 2 months (SD 8mo) selected to match the DS group on the basis of mental age. They were all administered tests that explored visual perception (Visual Perception Test - Subtest 4 and Line Orientation tests), visual imagery (imaging the colour of objects and the tail length of well-known animals), spatial imagery (mental rotation of visually presented or verbally evoked objects), and WM for visual-object and visual-spatial information. Individuals with WS exhibited specific difficulties in the visual-spatial, but not the visual-object, WM task. Instead, people with DS showed reduced performance in both tests. However, whereas the observed deficit in individuals with DS persisted when perceptual abilities were taken into account, the deficit in individuals with DS was compensated when their scores were adjusted for performance on perceptual tasks. These results support the hypothesis of a dissociation within the sketch-pad slave system in the WM model and reinforce the view of intellectual disability as a non-unitary condition.     

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.     

Psychosocial, cognitive, and motor functioning in patients with suspected Sotos syndrome: a comparison between patients with and without NSD1 gene alterations

The aim of this study was to investigate psychosocial, cognitive, and motor functioning in patients clinically suspected of Sotos syndrome and to examine differences between patients with deletions or mutations of the gene encoding nuclear SET domain-containing protein 1 (NSD1; the major cause of the syndrome) and those without such alterations. Twenty-nine participants (21 males, 8 females) clinically suspected of Sotos syndrome (mean age 11y 10mo [SD 10y 11mo], range 1y 10mo-48y 5mo) were divided into an NSD1 mutation group (n=12; 8 males, 4 females) and an NSD1 non-mutation group (n=17; 13 males, 4 females). Intelligence, behaviour problems, attention-deficit-hyperactivity disorder (ADHD) symptoms, temperament, adaptive behaviour, and motor functioning were assessed with an extensive test battery. Scores were compared with those of control groups, and scores of the two subgroups were compared with each other. The mean IQ in the 21 individuals tested was 76 (SD 16; range 47-105). High rates of behaviour problems were found and patients lagged 1y 7mo to 2y 7mo behind in aspects of adaptive behaviour. In comparison with a control group of patients with a learning disability, motor functioning was better. NSD1 mutation compared with NSD1 non-mutation patients showed easier temperament, and fewer NSD1 mutation patients scored in the clinical range for 'total behaviour problems' (3/11 vs 13/17), 'internalizing behaviour' (2/11 vs 11/17), and ADHD (0/9 vs 4/15).     

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.     

Academic performance in children with rolandic epilepsy

The aim of this study was to investigate the frequency of reading, writing, and calculation disabilities in children with typical rolandic epilepsy (RE) and healthy control children. We also aimed to define the possible electroclinical markers of specific cognitive dysfunctions in RE. School abilities were evaluated and compared in 20 children (eight males, 12 females; mean age 10y 3mo [SD 1y 7mo]; range 7y 9mo-12y 9mo) consecutively diagnosed with typical RE, and a group of 21 healthy controls (nine males, 12 females; mean age 10y 4mo [SD 1y 8mo]; range 7y 6mo-13y 3mo). All the children received standardized neuropsychological tests. For each patient an exhaustive seizure diary was kept and all the sleep electroencephalogram (EEG) recordings were reviewed. Specific difficulties with reading, writing, and calculation (diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition) were found in nine out of 20 children with RE and two out of 21 healthy controls (chi2=0.01). The specific learning disabilities in the RE group were correlated with a marked increase in epileptiform discharges during sleep (chi2=0.02) and an early onset of epilepsy (chi2=0.02). Our findings suggest that seizure onset before age 8 years and epileptiform discharges (more than 50% of the sleep EEG recording) in several tracings over more than a year are relevant markers for identifying patients at risk of developing academic difficulties.     

Effect of age and sex on maturation of sensory systems and balance control

Maintenance of postural balance requires an active sensorimotor control system. Current data are limited and sometimes conflicting regarding the influence of the proprioceptive, visual, and vestibular afferent systems on posture control in children. This study investigated the development of sensory organization according to each sensory component in relation to age and sex. A total of 140 children (70 males, 70 females; mean age 10y [SD 4y]; age range 3y 5mo-16y 2mo) and 20 adults (10 males, 10 females; mean age 30y 6mo [SD 8y 4mo]; age range 17y 2mo-49y 1mo) were examined using the Sensory Organization Test. Participants were tested in three visual conditions (eyes open, blindfolded, and sway-referenced visual enclosure) while standing on either a fixed or a sway-referenced force platform. Mean equilibrium scores for the six balance conditions showed rapid increases and maturation ceiling levels for age-related development of the sensorimotor control system. Proprioceptive function seemed to mature at 3 to 4 years of age. Visual and vestibular afferent systems reached adult level at 15 to 16 years of age, revealing differences between young males and females. Characterizing balance impairments can contribute to the diagnostic evaluation of neuromotor disorders.     

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.     

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.     

Binaural interaction in specific language impairment: an auditory evoked potential study

The aim of the study was to examine whether auditory binaural interaction, defined as any difference between binaurally evoked responses and the sum of monaurally evoked responses, which is thought to index functions involved in the localization and detection of signals in background noise, is atypical in a group of children with specific language impairment (SLI). Binaural interaction components (BICs) in the brainstem were compared in 19 children with SLI (13 males, six females; age range 7y 4mo-11y 10mo; mean age 9y 7mo [SD 1y 2mo]), and 31 comparison children with typical language development (16 males, 15 females; age range 7y 1mo-11y 4mo; mean age 9y 7mo [SD 1y 5mo]). Children with SLI had a significantly smaller BIC amplitude than the comparison group. However, no clear relationship was found between BIC measures and severity of language impairment. We conclude that, for some children, SLI may be associated with reduced binaural interaction which may hinder the detection or localization of speech sounds from noisy contexts during critical periods of language acquisition.     

Motor coordination, empathy, and social behaviour in school-aged children

Children with motor coordination problems are known to have emotional difficulties and poor social skills. The current study investigated whether children with poor motor ability have poor emotion recognition skills, and whether these could be linked to problems in social behaviour. It was hypothesized that difficulties in empathic ability might be related to the poor visuo-spatial processing ability identified in children with developmental coordination disorder (as defined by the American Psychiatric Association). The relationship between motor coordination, emotion recognition, and social behaviour was examined in a sample of 234 children (113 males, 121 females; mean age 9y 7mo, [SD 1y 8mo] age range 6y 8mo to 12y 11mo). From this sample two groups of 39 children each (17 females, 22 males), one group with motor difficulties (mean age 9y 11mo [SD 2y], range 6y 11mo to 12y 11mo) and the other of control children (mean age 10y [SD ly 11mo], range 6y 11mo to 12y 11mo), matched for age and sex, were compared using a set of six emotion recognition scales that measured both verbal and perceptual aspects of empathic ability. Children with motor difficulties were found to perform more poorly on scales measuring the ability to recognize static and changing facial expressions of emotion. This difference remained even when visuo-spatial processing was controlled. When controlling for emotion recognition and visuo-spatial organization, a child's motor ability remained a significant predictor of social behaviour.     

Executive functions and seizure-related factors in children with epilepsy in Western Norway

Executive functions (EFs), seizure-related factors, and school performance were studied in a population-based sample of children with epilepsy (n=117; 71 males, 46 females; mean age 10y 5mo [SD 2y]; range 6y-12y 11mo) and a comparison group (n=124; 71 males, 53 females; mean age 10y 1mo [SD 2y 1mo]; range 6y-12y 11mo). EF, cognitive function, depression, socioeconomic status, and school performance were examined. Patients with epilepsy performed significantly lower than the comparison group on all EF measures except incidental memory. Intellectual dysfunction and depression accounted for 43% of EF problems. All epilepsy syndrome groups (except Rolandic epilepsy) were associated with decreased EF in addition to early epilepsy onset, high seizure frequency, and polytherapy. Patients had more school performance problems than comparison children which were attributed partly to EF difficulties. All aspects of EF were affected in children with epilepsy and all epilepsy syndrome groups, except Rolandic epilepsy, influenced EF negatively. EF problems contributed to patients' school difficulties beyond intellectual dysfunction.     

A milk-free diet downregulates folate receptor autoimmunity in cerebral folate deficiency syndrome

In cerebral folate deficiency syndrome, the presence of autoantibodies against the folate receptor (FR) explains decreased folate transport to the central nervous system and the clinical response to folinic acid. Autoantibody crossreactivity with milk FR from different species prompted us to test the effect of a milk-free diet. Intervention with a milkfree diet in 12 children (nine males, three females; mean age 6y [SD 4y 11mo], range 1-19y), decreased autoantibody titer significantly from 2.08pmol of FR blocked per ml of serum (SD 2.1; range 0.24-8.35) to 0.35pmol (SD 0.49; range 0-1.32; p=0.012) over 3 to 13 months, whereas FR autoantibody titer increased significantly to 6.53 (SD 6.08; range 0.54-14.07; p=0.013) in nine children who were reexposed to milk for 6 to 14 weeks. In 12 children on a normal diet (eight males, four females; mean age 5y 5mo [SD 4y 1mo], range 1y 6mo-16y 4mo), the antibody titer increased significantly from 0.84pmol of FR blocked per ml (SD 0.39; range 0.24-1.44) to 3.04pmol (SD 1.42; range 0.84-6.01; p=0.001) over 10 to 24 months. Decreasing the autoantibody titer with a milk-free diet in conjunction with folinic acid therapy may be advocated for these patients.     

Increased visual cortex glucose metabolism contralateral to angioma in children with Sturge-Weber syndrome

Functional reorganization after focal brain injury can lead to altered cerebral metabolism of glucose. Sturge-Weber syndrome (SWS) with unilateral involvement is a clinical model for evaluating the effects of early focal brain injury on brain metabolism and function. In this study, 2-deoxy-2[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET) was used to measure glucose metabolism in cortex and basal ganglia, both ipsilateral and contralateral to the angioma, in 17 children (eight males, nine females; age range 1y 8mo-10y 4mo; mean 5y 7mo [SD 2y 11mo]) with unilateral SWS and epilepsy. The PET findings were compared with those of a control group of 11 age-matched children (four males, seven females; age range 3y-10y 8mo; mean 6y [SD 2y 10mo]) with partial epilepsy but normal magnetic resonance imaging and PET scans. In the SWS group, visual and parietal cortex showed decreased glucose metabolism on the side of the angioma (p=0.001) but increased metabolism on the contralateral side (p=0.002). In particular, glucose metabolism was very high in contralateral visual cortex of childrenwith SWS, showing severe occipital hypometabolism on the side of the angioma. Eight children with visual field defect showed increased metabolism in the contralateral visual cortex (p=0.012). These findings indicate that early, severe unilateral cortical damage in SWS may induce increased glucose metabolism in the contralateral visual cortex, probably reflecting reorganization.     

Co-occurrence of developmental delays among preschool children with attention-deficit-hyperactivity disorder

The aim of this study was to provide a comprehensive profile of the sensory, motor, language, and intellectual functioning of a non-referred community sample of 49 preschool children with attention-deficit-hyperactivity disorder (ADHD; 39 males, 10 females; mean age 4y 7mo [SD 7mo]; range 3y 10mo-6y) and 48 typically developing children (38 males, 10 females; mean age 4y 8mo [SD 6mo]; range 3y 11mo-6y) matched by age, sex, and maternal education who underwent a broad battery of neurodevelopmental tests. The results showed that the scores of the ADHD group were significantly lower than the comparison group on all measures. In addition, 23 (47%) of the children with ADHD had clinically significant co-occurring deficits in two or more areas. Logistic regression indicated that the only significant predictors of group classification were scores of verbal intelligence and motor and sensory functioning, accounting for 44.1% of the variance. These findings suggest that preschool children with ADHD have multiple developmental deficits over and above the core symptoms of ADHD and emphasize the importance of evaluating the sensorimotor functioning of preschool children with ADHD symptoms.     

Cognitive function in idiopathic generalized epilepsy of childhood

This study evaluated the cognitive profiles of children with idiopathic generalized epilepsy (IGE), uniformly treated with valproic acid with well-controlled seizures. Twenty-four were neuropsychologically evaluated. They comprised: 14 females, 10 males: 12 with generalized tonic-clonic seizures (GTCS), mean age 14y 4mo, SD ly 7mo, range 12y to 16y 4 mo; 12 with absence seizures (AS]) mean age 14y 5mo, SD ly 10mo, range 11y to 16y 4mo, with intellectual abilities within the normal range and age-appropriate scholastic skills, and 20 healthy controls (12 females, 8 males; mean age 14y 5mo, SD 1y 10mo, range 10y 7mo to 16y 7mo). As a group, children with IGE performed significantly poorer in all tests (non-verbal and verbal attention, verbal learning and memory, word fluency, and controlled sequential fine motor responses) excluding non-verbal memory. Analysis according to type of seizure revealed that both patient groups (AS and GTCS) had an attention deficit, whereas only children with AS showed deficits in verbal learning and memory, word fluency, and controlled fine motor responses. These results suggest a long-term risk of learning impairment for children with IGE, even if they have normal intelligence and their seizures are well controlled.     

The impact of sex and subtypes on cognitive and psychosocial aspects of ADHD

We compared the effect of sex and attention-deficit-hyperactivity disorder (ADHD) subtyping in groups of females and males. One hundred and one females with ADHD (mean age 10y 4mo [SD 2y 8mo]; range 5y-18y) were classified according to subtype by Diagnostic and Statistical Manual of Mental Disorders (4th edn) criteria (inattentive [ADHD-I]; combined [ADHD-C]) and balanced by subtype to 101 males (mean age 10y 5mo [SD 2y 9mo]; range 5y 4mo-17y 6mo). All children underwent IQ and reading assessment, and 109 underwent the continuous performance task (Test Of Variables of Attention [TOVA]). Parents completed the Conners' Abbreviated Rating Scale (ABRS), the Child Behavior Checklist (CBCL), learning disability questionnaires, and reported use and efficacy of methylphenidate. Teachers completed the Swanson, Kotkin, Agler, M-Flynn, and Pelham (SKAMP) rating scale. Sex differences were found only on the CBCL; females were more impaired on the attention (p<0.001) and somatization (p=0.028) subscales but not for IQ, other questionnaires, TOVA scores, methylphenidate treatment, or demographics. Females with ADHD-C, but not males, had significantly higher T-scores than females with ADHD-I on social, attention, delinquent, and aggressive behaviours. Regardless of sex, children with ADHD-C had higher scores on all CBCL subscales (p=0.047), ABRS (p<0.001), and SKAMP (p=0.03) than children with ADHD-I. The results support the supposition that ADHD in females is the same disorder as in males. ADHD subtyping was the important determinant of ADHD core symptoms; females with ADHD were found to have significant risk of psychopathology.     

Electrophysiological signs of supplementary-motor-area deficits in high-functioning autism but not Asperger syndrome: an examination of internally cued movement-related potentials

Aims  Motor dysfunction is common to both autism and Asperger syndrome, but the underlying neurophysiological impairments are unclear. Neurophysiological examinations of motor dysfunction can provide information about likely sites of functional impairment and can contribute to the debate about whether autism and Asperger syndrome are variants of the same disorder or fundamentally distinct neurodevelopmental conditions. We investigated the neurophysiology of internally determined motor activity in autism and Asperger syndrome via examination of movement-related potentials (MRPs).
Method  We used electroencephalography to investigate MRPs, via an internally cued movement paradigm, in the following three groups: (1) individuals with high-functioning autism (14 males, one female; mean age 13y 1mo, SD 4y 2mo, range 7y 8mo to 20y 9mo; mean Full-scale IQ 93.40, SD 20.72); (2) individuals with Asperger syndrome (10 males, two females; mean age 13y 7mo, SD 3y 9mo, range 8y 11mo to 20y 4mo; mean Full-scale IQ 103.25, SD 19.37), and (3) a healthy control group (13 males, seven females; mean age 14y 0mo, SD 3y 11mo; range 8y 4mo to 21y 0mo; mean Full-scale IQ 114.25, SD 11.29).
Results  Abnormal MRPs can reflect disruption of motor-related neural networks involving the basal ganglia, thalamus, and supplementary motor area. There was evidence for abnormal MRPs in autism (e.g. increased post-movement cortical activity, abnormal peak time) but not in Asperger syndrome.
Interpretation  The results support basal ganglia, thalamus, and supplementary motor area involvement as a likely source of motor dysfunction in autism, and provide further evidence for the neurobiological separateness of autism and Asperger syndrome.     

Mismatch negativity and frequency representational width in children with specific language impairment

The aim of this study was to compare the degree of frequency separation that is required between tones to generate mismatch negativity (MMN) in a group of children with specific language impairment (SLI) and a comparison group, who had their temporal processing abilities assessed in a previous experiment. Using a 1000Hz standard (85%) and 1020, 1050, and 1100Hz deviant tones presented at inter-stimulus intervals (ISIs) of 200 and 400ms, MMN was compared in 19 children with SLI (13 males, six females, age range 7y 4mo-11y 10mo, mean age 9y 7mo [SD 1y 2mo]), and 19 comparison children (13 males, six females, age range 7y 3mo-11y 4mo, mean age 9y 5mo [SD 1y 3mo]). Temporal processing ability was assessed by the Auditory Fusion Test-Revised. Children with SLI who had poor temporal processing abilities generated a positive mismatch response (P-MMR) for 2% tone contrasts at 400ms ISI but MMN with larger contrasts. These children also generated stronger MMN than the comparison group at 200ms ISI for 2% contrasts. Children with SLI who had good temporal processing abilities generated only P-MMR in response to contrasts up to 10% for both ISIs. Some children with SLI show an inverse relationship between frequency discrimination and temporal processing. Furthermore, certain stimulus-related and biological criteria may need to be met for P-MMR to switch to MMN.     

Gait function in newly diagnosed children with autism: Cerebellar and basal ganglia related motor disorder

We investigated gait in newly diagnosed children with autism. From our previous study with 6- to 14-year-olds, we hypothesized that motor symptoms indicative of basal ganglia and cerebellar dysfunction would appear across the developmental trajectory of autism. Two groups were recruited: children with autism (eight males, three females; mean age 5 y 10 mo [SD 9 mo]; range 4 y 4 mo-6 y 9 mo) and a comparison group of typically developing children (eight males, three females; mean age 5 y 9 mo [SD 1 y 1 mo]; range 4 y 3 mo-7 y 2 mo). The GAITRite Walkway was used to gather data from average gait and intra-walk measurements. Experienced physiotherapists analyzed gait qualitatively. Groups were matched according to age, height, weight, and IQ; although not statistically significant, IQ was lower in the group with autism. Spatiotemporal gait data for children with autism were compatible with findings from patients with cerebellar ataxia: specifically, greater difficulty walking along a straight line, and the coexistence of variable stride length and duration. Children with autism were also less coordinated and rated as more variable and inconsistent (i.e. reduced smoothness) relative to the comparison group. Postural abnormalities in the head and trunk suggest additional involvement of the fronto-striatal basal ganglia region. Abnormal gait features are stable across key developmental periods and are, therefore, promising for use in clinical screening for autism.