PubMed Health⌕ Search

Biomedical subjects

Isobel Heyman

Publications and source records attributed to Isobel Heyman.

10 recordsLinked to original sources
PubMed2006

Progressive increase of frontostriatal brain activation from childhood to adulthood during event-related tasks of cognitive control.

Higher cognitive inhibitory and attention functions have been shown to develop throughout adolescence, presumably concurrent with anatomical brain maturational changes. The relatively scarce developmental functional imaging literature on cognitive control, however, has been inconsistent with respect to the neurofunctional substrates of this cognitive development, finding either increased or decreased executive prefrontal function in the progression from childhood to adulthood. Such inconsistencies may be due to small subject numbers or confounds from age-related performance differences in block design functional MRI (fMRI). In this study, rapid, randomized, mixed-trial event-related fMRI was used to investigate developmental differences of the neural networks mediating a range of motor and cognitive inhibition functions in a sizeable number of adolescents and adults. Functional brain activation was compared between adolescents and adults during three different executive tasks measuring selective motor response inhibition (Go/no-go task), cognitive interference inhibition (Simon task), and attentional set shifting (Switch task). Adults compared with children showed increased brain activation in task-specific frontostriatal networks, including right orbital and mesial prefrontal cortex and caudate during the Go/no-go task, right mesial and inferior prefrontal cortex, parietal lobe, and putamen during the Switch task and left dorsolateral and inferior frontotemporoparietal regions and putamen during the Simon task. Whole-brain regression analyses with age across all subjects showed progressive age-related changes in similar and extended clusters of task-specific frontostriatal, frontotemporal, and frontoparietal networks. The findings suggest progressive maturation of task-specific frontostriatal and frontocortical networks for cognitive control functions in the transition from childhood to mid-adulthood.

Adolescent↗
PubMed2005

Incidence of anti-brain antibodies in children with obsessive-compulsive disorder.

BACKGROUND: Obsessions and compulsions may occur in the post-streptococcal disorders Sydenham's chorea and paediatric autoimmune neuropsychiatric disorders associated with streptococcus (PANDAS). The proposed mediators are anti-basal ganglia antibodies (ABGA). AIMS: We tested the hypothesis that post-streptococcal autoimmunity may have a role in'idiopathic'obsessive-compulsive disorder (OCD). METHOD: We examined 50 children with OCD for ABGA using enzyme-linked immunosorbent assay (ELISA) and western immunoblotting. The findings were compared with paediatric autoimmune (n=50), neurological (n=100) and streptococcal (n=40) controls. RESULTS: The mean ABGA binding on ABGA binding on ELISA was elevated in the patient cohort compared with all control groups (P<0.005 in all comparisons). Western immunoblotting revealed positive antibody binding (as seen in Sydenham's chorea) in 42% of the patient cohort compared with 2-10% of control groups (P<0.001 in all comparisons). CONCLUSIONS: Our findings support the hypothesis that central nervous system autoimmunity may have a role in a significant subgroup of cases of OCD. Further study is required to examine whether the antibodies concerned are pathogenic.

Adolescent↗
PubMed2004

Heterozygous PAX6 mutation, adult brain structure and fronto-striato-thalamic function in a human family.

Recent progress in developmental neurobiology and neuroimaging can be drawn together to provide new insight into the links between genetically specified processes of embryonic brain development and adult human brain structure and function. We used magnetic resonance imaging (MRI) to show that individuals with aniridia and deficits in executive and social cognition, due to heterozygous mutation of the neurodevelopmental control gene PAX6, have structural abnormalities of grey matter in anterior cingulate cortex, cerebellum and medial temporal lobe, as well as white matter deficits in corpus callosum. Functional MRI demonstrated reduced activation of fronto-striato-thalamic systems during performance of overt verbal fluency and nonsense sentence completion; the most consistent abnormality of verbal executive activation was located in the thalamus. These results provide the first evidence for brain functional differences in humans with PAX6 mutation that are compatible both with anatomical abnormalities in the same subjects and, more circumstantially, with the known roles of murine Pax6 in regional differentiation, axonal guidance and other aspects of early forebrain development. Highly conserved homeobox genes may be critical for normal ontogenesis of large-scale neurocognitive networks supporting phylogenetically advanced mental functions.

Adolescent↗
PubMed2003

The preliminary development of a new self-report measure for OCD in young people.

The aim of this study was to develop a reliable self-report instrument to assess obsessive-compulsive disorder (OCD) in young people. The children's Obsessional Compulsive Inventory (CHOCI) had good internal consistency, criterion validity and was significantly correlated with the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). This preliminary new measure could serve to provide a more efficient and accessible way of assessing OCD in young people.

Adolescent↗
PubMed2003

A population survey of mental health problems in children with epilepsy.

The 1999 British Child and Adolescent Mental Health Survey, a nationwide epidemiological study of rates of psychiatric disorder in children aged 5 to 15 years, provided the opportunity to investigate the mental health of children with epilepsy. These children and their families experience disability specifically because of additional emotional, behavioural, and relationship problems, and this is the first epidemiological study that directly measures these impairments. Information was obtained by interviewing a main carer and teacher for 10,316 children; 67 children with epilepsy were identified (35 males, 32 females; mean age 10 years 2 months, SD 2 years 11 months, range 5 to 15 years), and compared with the 47 children with diabetes (27 females, 20 males; mean age 10 years 4 months, SD 3 years 4 months, range 5 to 15 years) and 10,202 controls (50% male; mean age 9 years 11 months, SD 3 years 1 month, range 5 to 15 years). DSM-IV psychiatric diagnoses were derived from the Development and Well-Being Assessment in combination with the interview and a specialist clinician rating. Parental reports of emotional and behavioural problems, their impact, and associated peer problems were also obtained. Rates of psychiatric disorder were 37% (95% confidence interval [CI] 22 to 49) in epilepsy, 11% (95% CI 2 to 19%) in diabetes, and 9% (95% CI 9 to 10%) in control children. Parents of children with epilepsy consistently reported more problems, with greater impact and associated peer problems. Epilepsy, but not diabetes, was independently (adjusted for age, sex, and severe learning difficulties) associated with all behavioural variables in regression analyses. Emotional, behavioural, and relationship difficulties are common in children with epilepsy, and constitute a significant burden to the children and their families, indicating the need for effective mental health services for these children.

Adolescent↗