Right-handed Healthy Control Subjects Research Articles

M55. STRUCTURAL CHANGES RELEVANT TO MUSICAL DEFICITS IN SCHIZOPHRENIA

BackgroundMusic is a shared experience in human culture. The ability to perceive, enjoy, and produce music is closely related to a fundamental element of human cognition. We previously reported that patients with schizophrenia have musical disability compared to healthy comparison. Several replications have shown that patients with schizophrenia have low musical ability that correlates with poor cognitive functions and severe psychiatric symptoms. We also reported that thinner cortical thickness in the left temporal, parietal, and inferior frontal regions is associated with lower musical ability in schizophrenia. Next, we sought to investigate diffusion tensor images (DTI) and local gyrification index (LGI) in patients with schizophrenia.MethodsTwenty-two right-handed patients with schizophrenia (12 males and 10 females, mean age = 45.9 years) and 20 right-handed healthy control subjects (13 males and 7 females, mean age = 42.8 years) consented to participate in this study. We measured musical ability, cognitive functions, and clinical assessments using the Montreal Battery for Evaluation of Amusia (MBEA), Brief Assessment of Cognition in Schizophrenia (BACS), and Positive and Negative Syndrome Scale (PANSS), respectively. We employed automatic probabilistic tractography DTI analysis using TRActs Constrained by UnderLying Anatomy (TRACULA) available in the Freesurfer software for the reconstruction of major tract bundles. The LGI was measured by quantifying the gyrification in spherical three-dimensional regions of interest by the Freesurfer.ResultsWhole-tract diffusion characteristics in patients with schizophrenia and controls were significantly different. Fractional anisotropy (FA) was lower for patients with schizophrenia compared to controls in the left superior longitudinal fasciculus - parietal endings (slfp) (p < 0.001), left cingulum - angular bundle (cab) (p < 0.001), and corpus callosum - forceps minor (fminor) (p < 0.001). We found significant correlation between musical abilities and FA alterations in slfp in both controls and patients with schizophrenia. While lower musical ability corresponds to lower FA in slfp of controls (r = -0.572, p = 0.013), it is associated with higher FA in the slfp of patients with schizophrenia (r = 0.515, p = 0.021). We did not reveal any significant correlation of musical ability to LGI in patients with schizophrenia. In controls, the correlation of musical ability to LGI in parahippocampal region after adjusting for age, sex, and years of musical training.DiscussionThis study shows that TRACULA can be used for the detection of decrements in several DTI tracts including the left slfp, left cab, and fminor in patients with schizophrenia. It revealed that while lower musical ability correlates with lower FA values in the left slfp in controls, it is associated with higher FA values in the same region in patients with schizophrenia. This contradictory finding in controls and patients with schizophrenia with regard to white matter pathology may reflect left supramarginal region malfunction resulting in cortical pathology in patients with schizophrenia. The data suggest that patients with schizophrenia may be more susceptible to changes in cortical thickness in the supramarginal region, and white matter alteration in the left slfp. Further study is needed to confirm the results. The characteristics of grey and white matter in the left parietal region which are relevant to musical ability may provide insight into pathological progression in patients with schizophrenia.

F179. NEURAL CORRELATES IN MUSICAL DEFICITS IN SCHIZOPHRENIA

BackgroundSeveral studies have shown that patients with schizophrenia have low musical ability that correlates with poor cognitive functions and severe negative symptoms. Recently, using surface-based analysis, we reported that thinner cortical thickness in the left temporal, parietal, and inferior frontal regions is associated with lower musical ability in schizophrenia. Interestingly, thicker cortical thickness in the left supramarginal region correlates with lower musical ability in controls. Musical deficits such as congenital amusia was shown to contribute to white and grey matter pathophysiology in schizophrenia. We, therefore, sought to investigate diffusion tensor images (DTI) of patients with schizophrenia using an automated probabilistic tractography algorithm.MethodsTwenty-two right-handed patients with schizophrenia (12 males and 10 females, mean age = 45.9 years) and 20 right-handed healthy control subjects (13 males and 7 females, mean age = 42.8 years) consented to participate in this study. We measured musical ability, cognitive functions, and clinical assessments using the Montreal Battery for Evaluation of Amusia (MBEA), Brief Assessment of Cognition in Schizophrenia (BACS), and Positive and Negative Syndrome Scale (PANSS), respectively. We employed automatic probabilistic tractography DTI analysis using TRActs Constrained by UnderLying Anatomy (TRACULA) available in the Freesurfer software for the reconstruction of major tract bundles.ResultsWhole-tract diffusion characteristics in patients with schizophrenia and controls were significantly different. Fractional anisotropy (FA) was lower for patients with schizophrenia compared to controls in the left superior longitudinal fasciculus - parietal endings (slfp) (p < 0.001), left cingulum - angular bundle (cab) (p < 0.001), and corpus callosum - forceps minor (fminor) (p < 0.001). We found significant correlation between musical abilities and FA alterations in slfp in both controls and patients with schizophrenia. While lower musical ability corresponds to lower FA in slfp of controls (r = -0.572, p = 0.013), it is associated with higher FA in the slfp of patients with schizophrenia (r = 0.515, p = 0.021).DiscussionThis study shows that TRACULA can be used for the detection of decrements in several DTI tracts including the left slfp, left cab, and fminor in patients with schizophrenia. It revealed that while lower musical ability correlates with lower FA values in the left slfp in controls, it is associated with higher FA values in the same region in patients with schizophrenia. This contradictory finding in controls and patients with schizophrenia with regard to white matter pathology may reflect left supramarginal region malfunction resulting in cortical pathology in patients with schizophrenia. The data suggest that patients with schizophrenia may be more susceptible to changes in cortical thickness in the supramarginal region, and white matter alteration in the left slfp. Further study is needed to confirm the results. The characteristics of grey and white matter in the left parietal region which are relevant to musical ability may provide insight into pathological progression in patients with schizophrenia.

Abstract TP457: Brain Functional Alterations in Patients With Leukoaraiosis Associated Mild Cognitive Impairment

Background and aims: Recent studies demonstrated that a signal change of functional magnetic resonance imaging (fMRI) in certain brain areas during the resting state is a significant marker in patients with mild cognitive impairment (MCI). However, the research of resting-state fMRI (rs-fMRI) on leukoaraiosis (LA) associated MCI is scarce. The aim of this study was to investigate differences of the rs-fMRI default network between patients with LA-associated MCI and normal subjects, and provide functional imaging evidence of LA-associated MCI during early stages of the disease. Method: All subjects were outpatients or thier residents of the Department of Neurology of the Beijing Tiantan Hospital. They were divided into MCI group and control group according to their cognitive function assessing by the Hamilton Depression Scale, Clinical Dementia Rating (CDR), Mini Mental State Exam and Montreal Cognitive Assessment. Demographic information was recorded. Brain MRI characteristics were assessed using the Fazekas scale. The independent components of fMRI data were analyzed by fMRI tool box. The experimental data and confounding factors were analyzed by General Liner Model. Results: A total of 31 right-handed patients with LA-associated MCI and 27 right-handed healthy control subjects were included. The active areas participating in the resting state for LA-associated MCI group were mostly consistent with those of the control group. Compared with controls, the LA-associated MCI patients exhibited significantly lower blood oxygen level-dependent (BOLD) signals in the left anterior cingulate cortex (P=0.021) and right parahippocampal gyrus (P=0.032). Whereas higher BOLD signals during the resting state in LA-associated MCI patients were observed in the left caudate nucleus (P=0.015), right frontal lobe (P=0.004), superior temporal gyrus and inferior parietal gyrus (P=0.001), No significant difference was shown in the posterior cingulate cortex and precuneus (P=0.138). Conclusion: Our findings demonstrated that the discriminating functional activation in specific brain areas could be identified in patients with LA-associated MCI, which might be used as an useful neuroimaging evidence for the early recognition of these patients.

Motor function deficits in schizophrenia: an fMRI and VBM study

To investigate whether the motor functional alterations in schizophrenia (SZ) are also associated with structural changes in the related brain areas using functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM). A sample of 14 right-handed SZ patients and 14 right-handed healthy control subjects matched for age, sex, and education were examined with structural high-resolution T1-weighted MRI; fMRI images were obtained during right index finger-tapping task in the same session. fMRI results showed reduced functional activation in the motor areas (contralateral precentral and postcentral gyrus) and ipsilateral cerebellum in SZ subjects as compared to healthy controls (n = 14). VBM analysis also revealed reduced grey matter in motor areas and white matter reduction in cerebellum of SZ subjects as compared to controls. The present study provides an evidence for a possible association between structural alterations in the motor cortex and disturbed functional activation in the motor areas in persons affected with SZ during a simple finger-tapping task.

Defining language networks from resting‐state fMRI for surgical planning—a feasibility study

Presurgical language mapping for patients with lesions close to language areas is critical to neurosurgical decision-making for preservation of language function. As a clinical noninvasive imaging technique, functional MRI (fMRI) is used to identify language areas by measuring blood-oxygen-level dependent (BOLD) signal change while patients perform carefully timed language vs. control tasks. This task-based fMRI critically depends on task performance, excluding many patients who have difficulty performing language tasks due to neurologic deficits. On the basis of recent discovery of resting-state fMRI (rs-fMRI), we propose a "task-free" paradigm acquiring fMRI data when patients simply are at rest. This paradigm is less demanding for patients to perform and easier for technologists to administer. We investigated the feasibility of this approach in right-handed healthy control subjects. First, group independent component analysis (ICA) was applied on the training group (14 subjects) to identify group level language components based on expert rating results. Then, four empirically and structurally defined language network templates were assessed for their ability to identify language components from individuals' ICA output of the testing group (18 subjects) based on spatial similarity analysis. Results suggest that it is feasible to extract language activations from rs-fMRI at the individual subject level, and two empirically defined templates (that focuses on frontal language areas and that incorporates both frontal and temporal language areas) demonstrated the best performance. We propose a semi-automated language component identification procedure and discuss the practical concerns and suggestions for this approach to be used in clinical fMRI language mapping.

Quantitative Brain Diffusion-Tensor MRI Findings in Patients With Sickle Cell Disease

The aim of this study was to evaluate the microstructure of various regions of the brain using diffusion-tensor imaging (DTI) in patients with sickle cell disease (SCD) and in age- and sex-matched healthy control subjects. We also investigated the fiber tractography findings of the corpus callosum (CC) and corticospinal tracts (CSTs). Sixteen right-handed patients with SCD and 14 age- and sex-matched right-handed healthy control subjects were scanned using conventional MR sequences and DTI. Fractional anisotropy (FA) and apparent diffusion coefficients (ADCs) were calculated and regions of interest were selected in various brain areas (superior and inferior frontal, parietal, occipital, and temporal white matter areas), anterior and posterior periventricular areas, centrum semiovale, basal ganglia (lentiform nucleus, head of caudate nucleus), thalamus, cerebral peduncles, pons, cerebellar white matter areas, and CC. Diffusion-tensor tractography of the CC and CSTs was also performed. For the patients with SCD, significantly reduced FA values, increased ADC values, or both were seen clustered in several brain areas, including the CC, frontal white matter, centrum semiovale, periventricular areas, head of the caudate nucleus, thalamus, brainstem, and pons (p < 0.05). Statistically significant reductions in fiber counts in the first and fifth segments of the CC and in CSTs bilaterally were also observed in patients with SCD (p < 0.05). DTI shows microstructural abnormalities of various brain areas in patients with SCD.

Orbito-Frontal Cortex Volumes in Panic Disorder

ObjectiveGiven the association between the pathophysiology of panic disorder and prefrontal cortex function, we aimed to perform a volumetric MRI study in patients with panic disorder and healthy controls focusing on the in vivo neuroanatomy of the OFC.MethodsTwenty right-handed patients with panic disorder and 20 right-handed healthy control subjects were studied. The volumes of whole brain, total white and gray matters, and OFC were measured by using T1-weighted coronal MRI images, with 1.5-mm-thick slices, at 1.5T. In addition, for psychological valuation, Hamilton Depression Rating (HDRS) and Panic Agoraphobia Scales (PAS) were administered.ResultsUnadjusted mean volumes of the whole brain volume, total white and gray matter were not different between the patients and healthy controls while the patient group had significantly smaller left (t=-6.70, p<0.0001) and right (t=-5.86, p<0.0001) OFC volumes compared with healthy controls.ConclusionOur findings indicate an alteration of OFC morphology in the panic disorder and suggest that OFC abnormalities may be involved in the pathophysiology of panic disorder.

Diffusion Abnormalities in the Primary Sensorimotor Pathways in Writer's Cramp

To determine whether there are diffusion abnormalities along the fibers connecting sensorimotor regions, including the primary sensorimotor areas and the striatum, in patients with writer's cramp using voxel-based diffusion analysis and fiber tracking. Recent studies have shown structural changes in these regions in writer's cramp. Patient and control group comparison. Referral center for movement disorders. Twenty-six right-handed patients with writer's cramp and 26 right-handed healthy control subjects matched for sex and age. Clinical motor evaluations. Fractional anisotropy changes and results of fiber tracking in writer's cramp. Diffusion-tensor imaging revealed increased fractional anisotropy bilaterally in the white matter of the posterior limb of the internal capsule and adjacent structures in the patients with writer's cramp. Fiber tracking demonstrated that fractional anisotropy changes involve fiber tracts connecting the primary sensorimotor areas with subcortical structures. Diffusion abnormalities are present in fiber tracts connecting the primary sensorimotor areas with subcortical structures in writer's cramp. These abnormalities strengthen the role of the corticosubcortical pathways in the pathophysiologic mechanisms of writer's cramp.

The research on cortical excitability in schizophrenic patients

Objective To investigate the difference of motor threshold(MT)between the schizophrenic patients and normal volunteers.and analyze the change of cortical excitability in patients.Methods 48 righthanded patients with schizophrenia and 48 right-handed healthy control subjects were used signal-pulse Transcranial Magnetic Stimulation(sTMS)to detect the MT.Resuits MT in left(47.01±9.14)was higher than right (44.59±10.54)in patients,and reverse in normal controls(t1=2.11,P1＜0.05;t2=3.18,P 2＜0.01).Compared with the controls,the left MT in schizophrenia was increased significantly(t=2.36,P＜0.05),but no difference in right MT(t=0.10,P＞0.05).Conclusion The interhemispheric asymmetries of brain motor cortical excitability in patients with schizophrenia disorder was opposite to the controls,and the left cortical excitability in patients had a evident decrease relative to normal subjects. Key words: Schizophrenia; Transcranial magnetic stimulation; Motor threshold; Cortical excitability

CORTICAL THINNING IN IBS: IMPLICATIONS FOR HOMEOSTATIC, ATTENTION, AND PAIN PROCESSING

Chronic pain may be accompanied by abnormal functioning in pain, attention, or homeostatic systems. We recently identified abnormal rectal-evoked functional MRI responses in patients with irritable bowel syndrome (IBS) in brain regions associated with such systems, including the insula and anterior cingulate cortex (ACC).1 However, it is not known whether structural brain abnormalities contribute to these responses. We tested the hypothesis that abnormal cortical responses in IBS are at least partly due to structural differences within the insula and ACC. ### Methods. Right-handed healthy control subjects (n = 11, 7 women, 4 men; 24 to 50 years old) and patients with IBS (n = 9, 6 women, 3 men; 30 to 58 years old) provided written consent to procedures approved by the University Health Network Research Ethics Board. Control subjects were excluded if they had a history of bowel disorders, chronic pain, fibromyalgia, diabetes, or psychiatric illness. Patients were recruited from the Toronto Western Hospital Gastrointestinal Unit, met Rome III criteria2 for diagnosis of IBS, and had mild to moderate symptoms and pain for more than 2 years. Exclusion criteria were a history of …

Cognitive impairment after traumatic brain injury: a functional magnetic resonance imaging study using the Stroop task

The anterior cingulate cortex (ACC) plays a key role in cognition, motor function, and emotion processing. However, little is known about how traumatic brain injury (TBI) affects the ACC system. Our purpose was to compare, by functional magnetic resonance imaging (fMRI) studies, the patterns of cortical activation in patients with cognitive impairment after TBI and those of normal subjects. Cortical activation maps of 11 right-handed healthy control subjects and five TBI patients with cognitive impairment were recorded in response to a Stroop task during a block-designed fMRI experiment. Statistical parametric mapping (SPM99) was used for individual subjects and group analysis. In TBI patients and controls, cortical activation, found in similar regions of the frontal, occipital, and parietal lobes, resembled patterns of activation documented in previous neuroimaging studies of the Stroop task in healthy controls. However, the TBI patients showed a relative decrease in ACC activity compared with the controls. Cognitive impairment in TBI patients seems to be associated with alterations in functional cerebral activity, especially less activation of the ACC. These changes are probably the result of destruction of neural networks after diffuse axonal injury and may reflect cortical disinhibition attributable to disconnection or compensation for an inefficient cognitive process.

Magnetic resonance imaging study of corpus callosum abnormalities in patients with bipolar disorder

Background This study was conducted to further examine the hypothesis of abnormalities in size of corpus callosum in subjects with bipolar disorder. Methods Sixteen right-handed DSM-IV bipolar I patients and 27 right-handed healthy control subjects were studied. A 1.5-T GE Signa magnet was used, and three-dimensional gradient echo imaging (spoiled gradient recall acquisition) was conducted. Area measurements of corpus callosum were obtained blindly, with a semi-automated software, by a well-trained rater. Results Right-handed bipolar I patients had significantly smaller total corpus callosum, genu, posterior body, and isthmus areas compared with right-handed healthy control subjects (analysis of covariance with age, gender, and intracranial volume as covariates, p < .05). Partial correlation analyses, controlled for intracranial volumes, found a significant inverse relationship between age and total callosal, genu, anterior body, isthmus, and circularity in healthy control subjects ( p < .05) but not in bipolar patients ( p > .05). Conclusions Smaller callosal areas may lead to altered inter-hemispheric communication and be involved in the pathophysiology and cognitive impairment found in bipolar disorder.