Functional and Structural MR Imaging in Neuropsychiatric Disorders, Part 2: Application in Schizophrenia and Autism

Abstract

SUMMARY:During the past decade, the application of advanced MR imaging techniques in neuropsychiatric disorders has seen a rapid increase. Disease-specific alterations in brain function can be assessed by fMRI. Structural GM and WM properties are increasingly investigated by DTI and voxel-based approaches like VBM. These methods provide neurobiologic correlates for brain architecture and function, evaluation tools for therapeutic approaches, and potential early markers for diagnosis. Having provided insight into principles of functional and structural imaging and delineated common findings in mild cognitive impairment and Alzheimer disease in Part 1 of this review, we will now focus on autism and schizophrenia as common psychiatric disorders covering different stages of the life span. This review concludes by summarizing current applications, limitations, and future prospects in the field of MR imagingϪbased neuroimaging.ABBREVIATIONS: ACC ϭ anterior cingulate cortex; ASD ϭ autism spectrum disorders; BOLD ϭ blood oxygen level-dependent; DMN ϭ default mode network; DSM ϭ Diagnostic and Statistical Manual of Mental Disorders; FA ϭ fractional anisotropy; GM ϭ gray matter; HFA ϭ high-functioning autism; ICD ϭ International Classification of Diseases; RSN ϭ resting-state network; rsfMRI ϭ resting-state fMRI; VBM ϭ voxel-based morphometry T he past years have seen significant gains in the areas of functional and structural neuroimaging, particularly in their application to the field of neuropsychiatric disorders.MR imagingϪbased methods such as fMRI, DTI, and VBM provide neurobiologic correlates of neuropsychiatric disorders in vivo and potential early markers of disease for improved diagnosis. However, we still need to tune the available neuroimaging markers to provide individually applicable markers of disease to predict the risk of asymptomatic or oligosymptomatic subjects developing a specific neuropsychiatric disease. This is most relevant for the design and conduction of future primary or secondary prevention trials of neurodegenerative disorders such as Alzheimer disease or genetically determined disorders the course of which, however, can be dramatically improved through early intervention, such as schizophrenia or ASD. To date, the clinical application of MR imaging in neuropsychiatric diseases is mostly limited to the exclusion of macroscopic abnormalities. Part 1 delineated the methodologic basis and main findings in mild cognitive impairment and Alzheimer disease; this part summarizes major findings gained by applying these techniques to schizophrenia and ASD. We conclude with a discussion of the scope, limitations, and future prospects of functional and structural MR imaging techniques in neuropsychiatric disorders. SchizophreniaSchizophrenia is a chronic mental disorder characterized by severe perturbations in cognition, affect, and behavior. Delusions and hallucinations, predominantly auditory in type, are typical symptoms of schizophrenia, but not obligatory. With a lifetime prevalence of approximately...

Assessment of white matter integrity of autistic preschool children with diffusion weighted MR imaging

“…The social deficits may be related to frontal lobe dysfunction which plays a crucial role in social cognition network. The temporal region is responsible about language [1][2][3][4][5][6][7].…”

“…Functional and structural imaging studies reported disruption of the white matter in autism [7][8][9][10]. There is reduced volume of the white matter at voxel based morphometry [11][12][13][14][15][16][17], abnormalities of choline and glutamate of white matter at MR spectroscopy [18] and decreased connectivity at functional MR imaging of autistic children [19].…”

Neuroimaging in autism spectrum disorder: brain structure and function across the lifespan

“…74 Nonetheless, consistent diff erences in brain activation occur in regions that also show structural abnormalities, as highlighted in several recent reviews. [75][76][77] Findings from many studies have shown decreased activation in regions comprising the social brain network during tasks related to emotional processing or social cognition, including the amygdala, temporal-parietal junction, insula, and inferior frontal cortex; 71,[78][79][80][81][82][83][84] in frontostriatal circuitry in response to cognitive control tasks and repetitive behaviours; 75,[85][86][87][88] in language circuitry during communication tasks; [89][90][91] and in reward circuitry. [92][93][94][95] By contrast, abnormal increases in Series activation are found in response to irritants and direct gaze.…”

Consensus paper of the WFSBP Task Force on Biological Markers: Criteria for biomarkers and endophenotypes of schizophrenia part II: Cognition, neuroimaging and genetics

“…Such relations between function and structure in parietal, occipital and temporal cortices were not affected (Cocchi et al 2014). The most characteristic change found in structural neuroimaging of schizophrenia patients is a reduction of grey matter volume, which tends to be more pronounced on the left side of the brain, especially in frontotemporal and limbic regions (Mueller et al 2012;Fujiwara et al 2015).…”