Effects of Age of Onset of Tonic-Clonic Seizures on Neuropsychological Performance in Children

Forty-eight children (aged 9 to 15 years) with tonic-clonic seizures were administered a neuropsychological test battery. The children with seizures of early onset (before age 5) were significantly impaired relative to the children with later onset on 8 of the 14 measures in the battery. The deficits were seen on tasks whose requirements included the repetition of a simple motor act, attention and concentration, memory, and complex problem solving. These findings emphasize the need for further research to determine the causal factors of the greater dysfunction seen in the early onset group. RÉSUMÉ Quarante huit enfants ÁgÉs de 9 À 15 ans souffrant de crises Épileptiques tonico-cloniques ont ÉtÉÉtudiÉs avec une batterie de tests neuropsychologiques. Pour huit des quatorze mesures de cette batterie de tests les enfants dont les cirses avaient dÉbutÉ prÉcocÉment (avant cinq ans) se sont avÉrÉs Étre signiflcativement dÉtÉriorÉs par rapport À ceux dont les crises avaient dÉbutÉ plus tardivement. Les dÉficits se sont manifestÉs pour des tÁches nÉcessitant la rÉpÉtition d'un acte moteur simple, attention et concentration, mÉmoire et capacitÉÀ rÉsoudre des problÈmes complexes. Ces rÉsultats mettent l'accent sur la nÉcessitÉ de poursuivre les recherches afin de dÉterminer les facteurs responsables de la plus grande dysfonction observÉe chez les enfants dont l'Épilepsie a dÉbutÉ tÔt dans la vie. RESUMEN Se ha aplicado una bateria de tests neuro-psicolÓgicos a 48 niÑos de 9 a 15 aÑos de edad que padecÍan ataques tonico-clÓnicos. Los niÑos con ataques de comienzo precoz (antes de los 5 aÑos) mostraron incapacidades significativas compareÁndolos con niÑos con comienzos mÁs tardios en 8 de los 14 tests de la bateria. Los defectos fueron detectados en las pruebas cuyos requisitos incluÍan la repeticiÓn de un acto motor simple, atenciÓn y concentraciÓn, memoria y resoluciÓn de problemas complejos. Estos hallazgos indican la necesidad de continuar la inves-tigaciÓn para determinar los factores causales de la mayor disfunciÓn observada en el grupo de comienzo precoz. ZUSAMMENFASSUNG 48 Kinder (9 bis 15 Jahre alt) mit tonisch-klonischen KrÄmpfen wurden mit einer neuropsychologischen Testbatterie untersucht. Die Kinder mit einem FrÜhbeginn der AnfÄlle (vor dem Alter von 5 Jahren) zeigten sich bei 8 von 14 Tests der Serie deutlich beeintrÄchtigt im VerhÄltnis zu Kindern mit spÄterem Anfallsbeginn. Die Defekte traten bei Aufgaben auf, die folgende AnsprÜche stellten: Wiederholung einer einfachen motorischen Handlung, Aufmerksamkeit und Konzentration, GedÄchtnis und komplexes ProblemlÖsen. Diese Befunde deuten auf die Notwendigkeit weiterer Untersuchungen, um die ursÄchlichen Faktoren der grÖßeren Funktionseinbuße zu bestimmen, die bei Patienten mit frÜhem Anfallsbeginn beobachtet wird.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65238/1/j.1528-1157.1981.tb04102.x.pd

Compression of Auditory Space during Forward Self-Motion

<div><h3>Background</h3><p>Spatial inputs from the auditory periphery can be changed with movements of the head or whole body relative to the sound source. Nevertheless, humans can perceive a stable auditory environment and appropriately react to a sound source. This suggests that the inputs are reinterpreted in the brain, while being integrated with information on the movements. Little is known, however, about how these movements modulate auditory perceptual processing. Here, we investigate the effect of the linear acceleration on auditory space representation.</p> <h3>Methodology/Principal Findings</h3><p>Participants were passively transported forward/backward at constant accelerations using a robotic wheelchair. An array of loudspeakers was aligned parallel to the motion direction along a wall to the right of the listener. A short noise burst was presented during the self-motion from one of the loudspeakers when the listener’s physical coronal plane reached the location of one of the speakers (null point). In Experiments 1 and 2, the participants indicated which direction the sound was presented, forward or backward relative to their subjective coronal plane. The results showed that the sound position aligned with the subjective coronal plane was displaced ahead of the null point only during forward self-motion and that the magnitude of the displacement increased with increasing the acceleration. Experiment 3 investigated the structure of the auditory space in the traveling direction during forward self-motion. The sounds were presented at various distances from the null point. The participants indicated the perceived sound location by pointing a rod. All the sounds that were actually located in the traveling direction were perceived as being biased towards the null point.</p> <h3>Conclusions/Significance</h3><p>These results suggest a distortion of the auditory space in the direction of movement during forward self-motion. The underlying mechanism might involve anticipatory spatial shifts in the auditory receptive field locations driven by afferent signals from vestibular system.</p> </div

Cognition and bimanual performance in children with unilateral cerebral palsy: Protocol for a multicentre, cross-sectional study

© 2018 The Author(s). Background: Motor outcomes of children with unilateral cerebral palsy are clearly documented and well understood, yet few studies describe the cognitive functioning in this population, and the associations between the two is poorly understood. Using two hands together in daily life involves complex motor and cognitive processes. Impairment in either domain may contribute to difficulties with bimanual performance. Research is yet to derive whether, and how, cognition affects a child's ability to use their two hands to perform bimanual tasks. Methods/Design: This study will use a prospective, cross-sectional multi-centre observational design. Children (aged 6-12 years) with unilateral cerebral palsy will be recruited from one of five Australian treatment centres. We will examine associations between cognition, bimanual performance and brain neuropathology (lesion type and severity) in a sample of 131 children. The primary outcomes are: Motor - the Assisting Hand Assessment; Cognitive - Executive Function; and Brain - lesion location on structural MRI. Secondary data collected will include: Motor - Box and Blocks, ABILHAND- Kids, Sword Test; Cognitive - standard neuropsychological measures of intelligence. We will use generalized linear modelling and structural equation modelling techniques to investigate relationships between bimanual performance, executive function and brain lesion location. Discussion: This large multi-centre study will examine how cognition affects bimanual performance in children with unilateral cerebral palsy. First, it is anticipated that distinct relationships between bimanual performance and cognition (executive function) will be identified. Second, it is anticipated that interrelationships between bimanual performance and cognition will be associated with common underlying neuropathology. Findings have the potential to improve the specificity of existing upper limb interventions by providing more targeted treatments and influence the development of novel methods to improve both cognitive and motor outcomes in children with unilateral cerebral palsy

Hippocampal - diencephalic - cingulate networks for memory and emotion: An anatomical guide

This review brings together current knowledge from tract tracing studies to update and reconsider those limbic connections initially highlighted by Papez for their presumed role in emotion. These connections link hippocampal and parahippocampal regions with the mammillary bodies, the anterior thalamic nuclei, and the cingulate gyrus, all structures now strongly implicated in memory functions. An additional goal of this review is to describe the routes taken by the various connections within this network. The original descriptions of these limbic connections saw their interconnecting pathways forming a serial circuit that began and finished in the hippocampal formation. It is now clear that with the exception of the mammillary bodies, these various sites are multiply interconnected with each other, including many reciprocal connections. In addition, these same connections are topographically organised, creating further subsystems. This complex pattern of connectivity helps explain the difficulty of interpreting the functional outcome of damage to any individual site within the network. For these same reasons, Papez’s initial concept of a loop beginning and ending in the hippocampal formation needs to be seen as a much more complex system of hippocampal–diencephalic–cingulate connections. The functions of these multiple interactions might be better viewed as principally providing efferent information from the posterior medial temporal lobe. Both a subcortical diencephalic route (via the fornix) and a cortical cingulate route (via retrosplenial cortex) can be distinguished. These routes provide indirect pathways for hippocampal interactions with prefrontal cortex, with the preponderance of both sets of connections arising from the more posterior hippocampal regions. These multi-stage connections complement the direct hippocampal projections to prefrontal cortex, which principally arise from the anterior hippocampus, thereby creating longitudinal functional differences along the anterior–posterior plane of the hippocampus

Behaviour after cerebral lesions in children and adults. 1962.

It is generally believed that brain injuries vary in their effects according to the age at which they are sustained, but the nature and extent of these differences remain elusive. A full enquiry requires, ideally, the study of strictly comparable lesions in the young and the old, the opportunity for follow-up examinations extending over decades in both groups and, lastly, the availability of behavioural tasks for which normal attainment is known, and which are equally applicable to the brain-injured child and the brain-injured adult. The investigations of behavioural changes after brain injury in children and adults, reported here, are far from fulfilling all these requirements. In particular, these studies are obviously deficient with regard to our first postulate, that of comparable lesions. Identical lesions in children and adults are so rare that one is often forced to turn to animal experiments as a supplementary source of information. Admittedly, animal experiments introduce phylogenetic differences in addition to the ontogenetic ones; yet available animal studies can help to indicate some of the directions in which the answers to the ontogenetic question may be sought. Accordingly, we begin this account with a brief consideration of animal experiments, before presenting some of the results obtained in our laboratory in students of brain-injured about and children. © 2008 Blackwell Publishing Ltd

Visual discrimination of target displacement remains after damage to the striate cortex in humans

Damage to the striate cortex usually causes blindness in those regions of the visual field which map to the area of neural damage. Nonetheless, there are reports that some patients with such damage can localize and perform certain visual discriminations between light stimuli presented within the 'blind' area of the visual field. Experiments on animals with different brain areas ablated suggest that visual function is served by two principal projection pathways from the retina7,8. That to the striate cortex is primarily responsible for fine discrimination between stimulus parameters such as colour and spatial pattern, whereas that to the superior colliculus in the midbrain is responsible for visual localization of stimuli. The residual visual functions in patients with cortical damage are usually attributed to the non-striate retinal projection to the superior colliculus. We now present measurements of spatial discrimination in two observers with large visual field defects (scotomata) caused by damage to the striate cortical region. Both exhibit a near normal ability to discriminate displacements of targets when two lights are flashed sequentially in their defective visual field, but they are unable to discriminate spatial pattern or size. We argue that these results are consistent with the 'two visual systems' interpretation of ablation studies on non-human species