Schizophrenia: the big questions.
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Biomedical subjects
Publications and source records attributed to Nancy C Andreasen.
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The thalamus is an important relay structure in the brain that may be relevant to a variety of brain diseases. It is divided into multiple subnuclei with different cortical connections. The medial dorsal (MD) nucleus is particularly important because it forms key connections with the prefrontal cortex. The current study reports precise and efficient methods for measuring the whole thalamus and the MD with MRI that have a high degree of interrater reliability. A multispectral image acquisition and novel image processing technique were used to improve structure visibility. The tricolor image assigns a color to each of the T1, T2, and PD weighted images, represented by red, green, and blue, respectively. The manually defined regions were then used to train an artificial neural network (ANN) to automatically define both the whole thalamus and the MD. The ANN provides an efficient automated method, making studies using larger sample sizes more feasible.
Medical imaging has opened a new door into biomedical research. In order to study various diseases of the brain and detect their impact on brain structure, robust and user friendly image processing packages are required. These packages must be multi-faceted to distinguish variations in size, shape, volume, and the ability to detect longitudinal changes over the course of an illness. This paper describes the BRAINS2 image processing package, which contains both manual and automated tools for structural identification, methods for tissue classification and cortical surface generation. These features are described in detail, as well as the reliability of these procedures.
Sleep disturbances have been associated with schizophrenia, and are an especially prominent feature during the prodrome preceding psychotic relapse. In this study, we examined the changes in sleep quality following withdrawal of antipsychotic treatment, as well as the predictive value of sleep disturbances on symptom exacerbation. One hundred twenty-two patients with schizophrenia, schizophreniform disorder, or schizoaffective disorder underwent a 3-week medication wash-out prior to neuroimaging studies. Sleep quality was rated using items on the Hamilton Rating Scale for Depression (HAM-D), while symptom severity was measured using the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS). Sleep quality deteriorated progressively following antipsychotic discontinuation. Total insomnia score prior to antipsychotic withdrawal had a significant effect on the severity of psychotic symptoms at the last weekly assessment, while baseline terminal insomnia had a significant effect on disorganized symptoms at the end of the medication-free period. These findings were independent of baseline symptom severity. Our findings suggest that schizophrenia patients with sleep disturbances are at a greater risk for worsening of positive symptoms after antipsychotic discontinuation. The implications of these findings in research and clinical settings are discussed.
BACKGROUND: Given the enormous societal burden of schizophrenia, there has been a growing interest in its prevention during the past decade. Early detection and prompt treatment may improve outcome in schizophrenia. In this study, we examine the value of using pre-morbid cognitive impairment in early detection. METHODS: Standardized achievement tests Iowa Test of Basic Skills (ITBS) and Iowa Tests of Educational Development (ITED) at Grades 4, 8 and 11 were examined in 70 patients with schizophrenia and 147 comparison subjects without schizophrenia. The majority of comparison subjects later developed another major mental illness such as substance abuse or mood disorder. Receiver operating characteristic curves were used to test the efficiency and accuracy of pre-morbid cognitive tests for differentiating adolescents who will later develop schizophrenia from those who remain well or develop another mental illness. RESULTS: Although schizophrenia patients had lower mean percentile ranks than comparison subjects in every ITBS/ITED sub-test, these differences were only associated with small increases in risk for schizophrenia. Standardized scholastic tests achieved moderate sensitivity and specificity, and enhanced the detection of schizophrenia by three to five fold. However, positive predictive values were low. ITBS/ITED scores alone cannot be used in screening the general population, given the low positive predictive values. CONCLUSION: Combining ITBS/ITED scores with other risk factors, such as family history, may lead to more efficient early detection. Our findings illustrate the challenges facing the secondary prevention of schizophrenia. Priority should be given to developing efficient and accurate methods of early detection in order to reduce the dangers of making erroneous false positive diagnoses, and to decrease exposure to unnecessary treatment during the testing of early interventions.
PURPOSE: To evaluate brain morphology of adult males with nonsyndromic clefts of the lip and/or palate (NSCLP) in comparison to a matched healthy control group. METHODS: Brain structure was measured using quantitative analysis of magnetic resonance images. RESULTS: Subjects with NSCLP had significant abnormalities in brain morphology consisting of abnormally enlarged anterior regions of the cerebrum, and decreased volumes of the posterior cerebrum and cerebellum. Overall, the most severely affected region was the left temporal lobe. Furthermore, these structural abnormalities were directly related to cognitive dysfunction. CONCLUSIONS: These findings highlight the important relationship and interplay between face and brain development.