Autism Spectrum Disorders (ASD) are a set of neurodevelopmental disorders with an early-onset and a strong genetic component in their pathogenesis. According to genetic and epidemiological data, ASD ...relatives present personality traits similar to, but not as severe as the defining features of ASD, which have been indicated as the "Broader Autism Phenotype" (BAP). BAP features seem to be more prevalent in first-degree relatives of individuals with ASD than in the general population. Characterizing brain profiles of relatives of autistic probands may help to understand ASD endophenotype. The aim of this review was to provide an up-to-date overview of research findings on the neurostructural and neurofunctional substrates in parents of individuals with ASD (pASD). The primary hypothesis was that, like for the behavioral profile, the pASD express an intermediate neurobiological pattern between ASD individuals and healthy controls. The 13 reviewed studies evaluated structural magnetic resonance imaging (MRI) brain volumes, chemical signals using magnetic resonance spectroscopy (MRS), task-related functional activation by functional magnetic resonance imaging (fMRI), electroencephalography (EEG), or magnetoencephalography (MEG) in pASD.The studies showed that pASD are generally different from healthy controls at a structural and functional level despite often not behaviorally impaired. More atypicalities in neural patterns of pASD seem to be associated with higher scores at BAP assessment. Some of the observed atypicalities are the same of the ASD probands. In addition, the pattern of neural correlates in pASD resembles that of adult individuals with ASD, or it is specific, possibly due to a compensatory mechanism. Future studies should ideally include a group of pASD and HC with their ASD and non-ASD probands respectively. They should subgrouping the pASD according to the BAP scores, considering gender as a possible confounding factor, and correlating these scores to underlying brain structure and function. These types of studies may help to understand the genetic mechanisms involved in the various clinical dimension of ASD.
Clinical guidelines recommend using neuroimaging, Prechtls' General Movements Assessment (GMA), and Hammersmith Infant Neurological Examination (HINE) to diagnose cerebral palsy (CP) in infancy. ...Previous studies provided excellent sensitivity and specificity for each test in isolation, but no study has examined the pooled predictive power for early diagnosis.
We performed a retrospective case-control study of 441 high-risk infants born between 2003 and 2014, from three Italian hospitals. Infants with either a normal outcome, mild disability, or CP at two years, were matched for birth year, gender, and gestational age. Three-month HINE, GMA, and neuroimaging were retrieved from medical records. Logistic regression was conducted with log-likelihood and used to determine the model fit and Area Under the Curve (AUC) for accuracy.
Sensitivity and specificity for detecting CP were 88% and 62% for three-month HINE, 95% and 97% for absent fidgety GMs, and 79% and 99% for neuroimaging. The combined predictive power of all three assessments gave sensitivity and specificity values of 97.86% and 99.22% (PPV 98.56%, NPV 98.84%).
CP can be accurately detected in high-risk infants when these test findings triangulate. Clinical implementation of these tools is likely to reduce the average age when CP is diagnosed, and intervention is started.
Some key behavioural traits of Autism Spectrum Disorders (ASD) have been hypothesized to be due to impairments in the early activation of subcortical orienting mechanisms, which in typical ...development bias newborns to orient to relevant social visual stimuli. A challenge to testing this hypothesis is that autism is usually not diagnosed until a child is at least 3 years old. Here, we circumvented this difficulty by studying for the very first time, the predispositions to pay attention to social stimuli in newborns with a high familial risk of autism. Results showed that visual preferences to social stimuli strikingly differed between high-risk and low-risk newborns. Significant predictors for high-risk newborns were obtained and an accurate biomarker was identified. The results revealed early behavioural characteristics of newborns with familial risk for ASD, allowing for a prospective approach to the emergence of autism in early infancy.
Environmental enrichment (EE) was shown recently to accelerate brain development in rodents. Increased levels of maternal care, and particularly tactile stimulation through licking and grooming, may ...represent a key component in the early phases of EE. We hypothesized that enriching the environment in terms of body massage may thus accelerate brain development in infants. We explored the effects of body massage in preterm infants and found that massage accelerates the maturation of electroencephalographic activity and of visual function, in particular visual acuity. In massaged infants, we found higher levels of blood IGF-1. Massage accelerated the maturation of visual function also in rat pups and increased the level of IGF-1 in the cortex. Antagonizing IGF-1 action by means of systemic injections of the IGF-1 antagonist JB1 blocked the effects of massage in rat pups. These results demonstrate that massage has an influence on brain development and in particular on visual development and suggest that its effects are mediated by specific endogenous factors such as IGF-1.
Abstract Background High-risk infant follow-up programs provide early identification and referral for treatment of neurodevelopmental delays and impairments. In these programs, a standardized ...neurological examination is a critical component of evaluation for clinical and research purposes. Methods To address primary challenges of provider educational diversity and standardized documentation, we designed an approach to training and implementation of the Hammersmith Infant Neurological Examination with precourse materials, a workshop model, and adaptation of the electronic medical record. Conclusions Provider completion and documentation of a neurological examination were evaluated before and after Hammersmith Infant Neurological Examination training. Standardized training and implementation of the Hammersmith Infant Neurological Examination in a large high-risk infant follow-up is feasible and effective and allows for quantitative evaluation of neurological findings and developmental trajectories.
There is overwhelming evidence that autism spectrum disorder (ASD) is related to altered brain connectivity. While these alterations are starting to be well characterized in subjects where the ...clinical picture is fully expressed, less is known on their earlier developmental course. In the present study we systematically reviewed current knowledge on structural connectivity in ASD infants and toddlers. We searched PubMed and Medline databases for all English language papers, published from year 2000, exploring structural connectivity in populations of infants and toddlers whose mean age was below 30 months. Of the 264 papers extracted, four were found to be eligible and were reviewed. Three of the four selected studies reported higher fractional anisotropy values in subjects with ASD compared to controls within commissural fibers, projections fibers, and association fibers, suggesting brain hyper-connectivity in the earliest phases of the disorder. Similar conclusions emerged from the other diffusion parameters assessed. These findings are reversed to what is generally found in studies exploring older patient groups and suggest a developmental course characterized by a shift toward hypo-connectivity starting at a time between two and four years of age.
Objective
Subjects with severe hemiplegic cerebral palsy have increased ipsilateral corticospinal projections from their noninfarcted cortex. We investigated whether their severe impairment might, in ...part, be caused by activity‐dependent, competitive displacement of surviving contralateral corticospinal projections from the affected cortex by more active ipsilateral corticospinal projections from the nonaffected cortex, thereby compounding the impairment.
Methods
Transcranial magnetic stimulation (TMS) characterized corticospinal tract development from each hemisphere over the first 2 years in 32 healthy children, 14 children with unilateral stroke, and 25 with bilateral lesions. Magnetic resonance imaging and anatomic studies compared corticospinal tract growth in 13 patients with perinatal stroke with 46 healthy subjects.
Results
Infants with unilateral lesions initially had responses after TMS of the affected cortex, which became progressively more abnormal, and seven were eventually lost. There was associated hypertrophy of the ipsilateral corticospinal axons projecting from the noninfarcted cortex. Magnetic resonance imaging and anatomic studies demonstrated hypertrophy of the corticospinal tract from the noninfarcted hemisphere. TMS findings soon after the stroke did not predict impairment; subsequent loss of responses and hypertrophy of ipsilateral corticospinal axons from the noninfarcted cortex predicted severe impairment at 2 years. Infants with bilateral lesions maintained responses to TMS from both hemispheres with a normal pattern of development.
Interpretation
Rather than representing “reparative plasticity,” increased ipsilateral projections from the noninfarcted cortex compound disability by competitively displacing surviving contralateral corticospinal projections from the infarcted cortex. This may provide a pathophysiological explanation for why signs of hemiplegic cerebral palsy appear late and progress over the first 2 years of life. Ann Neurol 2007
•There is a strong correlation between brain lesion severity and visual function, evident also with a Structural MRI.•It is confirmed the validity of MRI semi-quantitative scale published by Fiori et ...al. (2014).•There is a frequent association of PVL with thalamic lesions with important repercussion on visual function.
To systematically explore the relationship between type and severity of brain lesion on Magnetic Resonance Imaging (MRI) and visual function in a large cohort of children with periventricular leukomalacia (PVL).
94 children with bilateral cerebral palsy (CP) and history of PVL were recruited at Stella Maris Scientific Institute in Pisa (Italy). We included data of participants (72) with at least one MRI after the age of three years and an evaluation of visual function including fixation, following, saccades, nystagmus, acuity, visual field, stereopsis and color perception.
Brain lesions location and extent were assessed by a semi-quantitative MRI-scale for children with CP.
Brain lesion severity strongly correlated with visual function total score (global MRI score p = .000; hemispheric score p = .001 and subcortical score p = .000). Moreover, visual acuity, visual field, stereopsis and colour were compromised when a cortical damage was present, while ocular motricity (and in particular fixation and saccades) were compromised in presence of subcortical brain damage.
Structural MRI is valuable for understanding the relationship between brain lesion severity and visual function in children with CP.
Early key visual skills, such as tracking objects, sustaining gaze, and shifting attention, rapidly develop within the first 6 months of infant life. These abilities play a significant role in the ...development of cognitive functions but are frequently compromised in infants at risk of developing neurodevelopmental disorders. This systematic review evaluates the potential of early vision function in the prediction of cognition at or above 12 months. Five databases were searched for relevant articles, and their quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies tool. Eight studies were suitable, including 521 preterm-born infants at varying risk of developing Cerebral Palsy (CP). Each study showed a significant correlation between vision and cognitive outcome. Predictive analysis including sensitivity and specificity was possible for three studies. Methodological quality was variable. Sensitivity ranged between 57 and 100% in the vision function assessments items, while specificity ranged from 59 to 100%. In conclusion, early vision showed strong correlation with cognition ≥ 12 months. While no single vision assessment was found to be superior, evaluation of specific functions, namely fixation and following, both at term age and between 3 and 6 months, demonstrated strong predictive validity.
Visual functions are often impaired in preterm infants with periventricular haemorrhagic infarction, because of the involvement of the region where the optic radiations are located. In some cases an ...unexpected sparing of the visual fields has been described, and related to the plasticity of thalamo‐cortical afferents that are supposedly able to bypass the lesion when it occurs in the early third trimester of gestation. We systematically reviewed the literature in the field to determine the limits and potentials of this type of reorganization. We found four studies meeting our criteria, from which we extracted case reports on 19 individuals with intraventricular haemorrhagic infarction. Eleven of the 19 did not have visual field defects, five had a bilateral visual field defect, and the remaining three had a unilateral visual field defect. The involvement of the optic radiations was often associated with normal visual fields as only one of the four individuals with damaged optic radiations showed visual field defects. Conversely, the presence of basal ganglia/thalamus involvement apparently prevented such reorganization, as the only two individuals with unilateral field restriction and available magnetic resonance imaging data both showed abnormalities in those structures. Consistent with this, we report on a further individual in which visual field restriction was associated with abnormal tractography on brain magnetic resonance imaging. Overall, this review supports the existence of effective mechanisms of plastic reorganization that allow a rewiring of geniculo‐calcarine connections with restoration of full field vision but which are hindered by the involvement of the basal ganglia and thalamus.
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