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Biomedical subjects

Therese van Amelsvoort

Publications and source records attributed to Therese van Amelsvoort.

3 recordsLinked to original sources
PubMed2002

Mood, cognition and Alzheimer's disease.

There is good evidence for sex differences in brain disease, and that oestrogen modulates brain development and ageing. For example, females are significantly more likely to suffer from Alzheimer's disease, depression and late-onset psychosis than are men. Moreover, hormone replacement therapy may reduce the rate of cognitive decline in post-menopausal women and reduce their risk of developing Alzheimer's disease (as compared to post-menopausal women who do not take hormone replacement therapy). The neurobiological basis of these differences in brain disease and ageing was unknown until relatively recently. In this chapter we discuss results of studies demonstrating that sex steroids (i) are crucial for development and ageing of brain regions affected in Alzheimer's disease; (ii) interact with neuronal networks and chemical systems at many different levels in brain, and (iii) affect mood and cognitive function in elderly women without Alzheimer's disease. The current literature supports the hypothesis that sex steroids can modulate brain ageing and provides a number of potential neurobiological explanations for the cognitive effects of hormone replacement therapy. There is only limited evidence that hormone replacement therapy is effective in women already suffering from Alzheimer's disease. Nonetheless, recent work may lead to new prevention strategies for age-related cognitive decline and brain diseases such as Alzheimer's disease.

Aged↗
PubMed2002

Brain anatomy and sensorimotor gating in Asperger's syndrome.

Asperger's syndrome (an autistic disorder) is characterized by stereotyped and obsessional behaviours, and pervasive abnormalities in socio-emotional and communicative behaviour. These symptoms lead to social exclusion and a significant healthcare burden; however, their neurobiological basis is poorly understood. There are few studies on brain anatomy of Asperger's syndrome, and no focal anatomical abnormality has been reliably reported from brain imaging studies of autism, although there is increasing evidence for differences in limbic circuits. These brain regions are important in sensorimotor gating, and impaired 'gating' may partly explain the failure of people with autistic disorders to inhibit repetitive thoughts and actions. Thus, we compared brain anatomy and sensorimotor gating in healthy people with Asperger's syndrome and controls. We included 21 adults with Asperger's syndrome and 24 controls. All had normal IQ and were aged 18-49 years. We studied brain anatomy using quantitative MRI, and sensorimotor gating using prepulse inhibition of startle in a subset of 12 individuals with Asperger's syndrome and 14 controls. We found significant age-related differences in volume of cerebral hemispheres and caudate nuclei (controls, but not people with Asperger's syndrome, had age-related reductions in volume). Also, people with Asperger's syndrome had significantly less grey matter in fronto-striatal and cerebellar regions than controls, and widespread differences in white matter. Moreover, sensorimotor gating was significantly impaired in Asperger's syndrome. People with Asperger's syndrome most likely have generalized alterations in brain development, but this is associated with significant differences from controls in the anatomy and function of specific brain regions implicated in behaviours characterizing the disorder. We hypothesize that Asperger's syndrome is associated with abnormalities in fronto-striatal pathways resulting in defective sensorimotor gating, and consequently characteristic difficulties inhibiting repetitive thoughts, speech and actions.

Adolescent↗