Charles B. Malpas

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There is growing interest in the neurobiological substrate of general intelligence. Psychometric estimates of general intelligence are reduced in a range of neurological disorders, leading to practical application as sensitive, but non-specific, markers of cerebral disorder. This study examined estimates of general intelligence in neurotypical adults using(More)
BACKGROUND Remote structural and functional changes have been previously described after stroke and may have an impact on clinical outcome. We aimed to use multimodal MRI to investigate contralesional subcortical structural and functional changes 3 months after anterior circulation ischemic stroke. METHODS Fifteen patients with acute ischemic stroke had(More)
We examined the effect of a single dose of methylphenidate (MPH) on whole brain functional connectivity, assessed using resting state functional MRI (rsfMRI), in young people with ADHD. 16 young people with ADHD participated in two rsfMRI scans in a randomized, placebo-controlled study with an acute dose of MPH (20 mg). 15 typically developing controls also(More)
BACKGROUND To evaluate a new semi-automated segmentation method for calculating hippocampal volumes and to compare results with standard software tools in a cohort of people with subjective memory complaints (SMC) and mild cognitive impairment (MCI). METHODS Data from 58 participants, 39 with SMC (17 male, 22 female, mean age 72.6) and 19 with MCI (6(More)
BACKGROUND The symptom profile and neuropsychological functioning of individuals with Attention Deficit/Hyperactivity Disorder (ADHD), change as they enter adolescence. It is unclear whether variation in brain structure and function parallels these changes, and also whether deviations from typical brain development trajectories are associated with(More)
PURPOSE To investigate whether there are any white matter changes in a 6-month follow-up of mild-moderate Alzheimer's patients using diffusion tensor imaging (DTI). MATERIALS AND METHODS We recruited 18 mild-moderate Alzheimer's disease patients and they underwent magnetic resonance imaging (MRI) at recruitment and at 6-month follow-up. Diffusion MRI(More)
PURPOSE White matter development during childhood and adolescence is characterised by increasing white matter coherence and organisation. Commonly used scalar metrics, such as fractional anisotropy (FA), are sensitive to multiple mechanisms of white matter change and therefore unable to distinguish between mechanisms that change during development. We(More)
Previous studies in pediatric traumatic brain injury (TBI) have been variable in describing the effects of injury severity on white-matter development. The present study used diffusion tensor imaging to investigate prospective sub-acute and longitudinal relationships between early clinical indicators of injury severity, diffusion metrics, and(More)
BACKGROUND Alzheimer's disease (AD) is characterized by two cardinal pathologies, which have different topological distributions. The differential anatomical distributions of these pathologies raise the possibility that they exert differential effects on brain networks. OBJECTIVES To investigate whether cerebrospinal fluid (CSF) biomarkers of the cardinal(More)
Although lower brain volume is a consistent neuroimaging finding in attention deficit hyperactivity disorder (ADHD), we lack an understanding of whether this effect is driven by changes in cortical thickness or surface area, which are governed by distinct neurodevelopmental processes. This study examined ADHD-control differences in cortical thickness,(More)