5,871 research outputs found
A physiological approach to motor development within and across domains
No full texthis commentary is on the original article by Hitzert et al. on pages 869–876 of this issue
Methodological note: Video analysis of the early development of Rett syndrome—one method for many disciplines
No full textRegression in Rett syndrome: Developmental pathways to its onset
No full textRett syndrome (RTT) is an X-linked genetic disorder that occurs predominantly in females. The clinical picture associated with RTT is defined by core and supportive consensus criteria, with a period of behavioural regression being a conditio sine qua non. This review sheds light on atypical neurofunctions and potential behavioural biomarkers before the onset of regression. The main focus lies on (a) motor development, especially on purposeful hand movements and the occurrence of stereotypies; and (b) speech-language and socio-communicative development. We outline potentially specific atypical behavioural patterns in these domains (e.g., vocalisations on inspiratory airstream) and different developmental traits of regression: (i) non-achievement of certain milestones: ‘regression’, here, might point to the fact that the lack of respective behavioural patterns appeared more and more worrisome with increasing age; and (ii) developmental milestones were achieved and functions deteriorate or even get lost during regression. To conclude, we are not quite there yet, but seem to be on the right track towards defining new and reliable neurofunctional markers for early detection of RTT
Contributing to the early detection of Rett syndrome: The potential role of auditory Gestalt perception
No full textAbstractTo assess whether there are qualitatively deviant characteristics in the early vocalizations of children with Rett syndrome, we had 400 native Austrian–German speakers listen to audio recordings of vocalizations from typically developing girls and girls with Rett syndrome. The audio recordings were rated as (a) inconspicuous, (b) conspicuous or (c) not able to decide between (a) and (b). The results showed that participants were accurate in differentiating the vocalizations of typically developing children compared to children with Rett syndrome. However, the accuracy for rating verbal behaviors was dependent on the type of vocalization with greater accuracy for canonical babbling compared to cooing vocalizations. The results suggest a potential role for the use of rating child vocalizations for early detection of Rett syndrome. This is important because clinical criteria related to speech and language development remain important for early identification of Rett syndrome
Central Pattern Generators and Their Significance for the Foetal Motor Function
No full textAuch wenn die Existenz der Central Pattern Generators (CPGs) schon seit Ende des 19. Jahrhunderts bekannt ist, ist man noch immer weit davon entfernt, die präzise Funktion dieser faszinierenden neuronalen Netzwerke zu verstehen. CPGs generieren endogen – in der Abwesenheit oszillatorischer Inputs – rhythmische Bewegungsmuster. Einige CPGs sind kontinuierlich aktiv, wie zum Beispiel der CPG für den Atemrhythmus; andere CPGs (wie jene für Lokomotion oder rhythmische Aktivitäten der Nahrungsaufnahme) müssen erst neuronal und/oder hormonell getriggert werden. Damit rhythmisches Verhalten an die Umgebungsbedingungen angepasst werden kann, bedarf es modulierender Inputs von supraspinalen Strukturen und der Peripherie. In der frühesten Entwicklung erzeugen die noch unreifen CPGs spontane embryonale/fötale Bewegungen, die ihrerseits die Reifung der sich entwickelnden Strukturen gewährleisten. Die Beurteilung früher fötaler und neonataler Bewegungen ist von klinischer Relevanz, da Hirnläsionen den modulierenden Input auf den CPG reduzieren. Die daraus resultierende Monotonie der Bewegungen ist ein zuverlässiges Zeichen neurologischer Beeinträchtigung.Although evidence for the existence of endogenously generated motor activity goes back to experiments conducted more than a century ago, a lot remains to be learnt about the fascinating network that is the central pattern generator (CPG). CPGs are neuronal circuits that can produce rhythmic motor patterns in the absence of oscillatory input. Some CPGs operate continuously (e. g., breathing movements); others are activated to perform specific behavioural tasks (e. g., locomotion). In order to lend flexibility to the motor output, supraspinal projections activate, inhibit, and, most of all, modulate the CPG activity, as does the sensory feedback. Embryonic and foetal motor patterns have all the characteristics of being endogenously generated. At no other stage of development is the neural structure so closely related to its own function. It only takes a few neurons to generate basic movements, which are, in turn, necessary for further development of the structure. Apart from the general interest in the evolution of early motor activity, the observation and assessment of spontaneous foetal and neonatal motility has also clinical implications, since a reduced CPG modulation results in less variable movements and indicates foetal or neonatal compromise
The enigma of regression in neurodevelopmental and genetic disorders: What have we learned?
No full textThe contribution of environmental exposure to the etiology of autism spectrum disorder
No full textAutism spectrum disorder (ASD) is a neurodevelopmental condition of heterogeneous etiology. While it is widely recognized that genetic and environmental factors and their interactions contribute to autism phenotypes, their precise causal mechanisms remain poorly understood. This article reviews our current understanding of environmental risk factors of ASD and their presumed adverse physiological mechanisms. It comprehensively maps the significance of parental age, teratogenic compounds, perinatal risks, medication, smoking and alcohol use, nutrition, vaccination, toxic exposures, as well as the role of extreme psychosocial factors. Further, we consider the role of potential protective factors such as folate and fatty acid intake. Evidence indicates an increased offspring vulnerability to ASD through advanced maternal and paternal age, valproate intake, toxic chemical exposure, maternal diabetes, enhanced steroidogenic activity, immune activation, and possibly altered zinc–copper cycles and treatment with selective serotonin reuptake inhibitors. Epidemiological studies demonstrate no evidence for vaccination posing an autism risk. It is concluded that future research needs to consider categorical autism, broader autism phenotypes, as well as autistic traits, and examine more homogenous autism variants by subgroup stratification. Our understanding of autism etiology could be advanced by research aimed at disentangling the causal and non-causal environmental effects, both founding and moderating, and gene–environment interplay using twin studies, longitudinal and experimental designs. The specificity of many environmental risks for ASD remains unknown and control of multiple confounders has been limited. Further understanding of the critical windows of neurodevelopmental vulnerability and investigating the fit of multiple hit and cumulative risk models are likely promising approaches in enhancing the understanding of role of environmental factors in the etiology of ASD
- …
