Psychiatric Disorders

Thursday 15 May 2014

Masaya Misaki¹, Teresa Victor¹, Hideo Suzuki¹, Kent Teague², Brent McKinney³, Patrick Bellgowan^1,4, Jonathan Savitz^1,4, Wayne Drevets^1,5, and Jerzy Bodurka^1,6
1Laureate Institute for Brain Research, Tulsa, OK, United States, ²Dept. of Surgery, University of Oklahoma College of Medicine, OK, United States,³Dept. of Mathematical and Computer Sciences, University of Tulsa, OK, United States, ⁴Dept. of Medicine, Tulsa School of Community Medicine, University of Tulsa, OK, United States, ⁵Janssen Pharmaceuticals, LLC, of Johnson & Johnson, Inc., Titusville, NJ, United States, ⁶College of Engineering, University of Oklahoma, OK, United States

Subtypes of nucleus accumbens (NAcc) activation for anticipation of gains and losses were identified for healthy and major depressive disorder (MDD) subjects. We used hierarchical clustering analysis to categorize NAcc activation patterns in individual subjects. Majority of subjects had typical NAcc activity; increased activity to gain and less active to loss. Hyper- and hypo-active subtypes were also found, which showed increase or decreased activity to both gains and losses. These hyper- and hypo-active types were seen in both healthy and MDD groups with the same percentage. In MDD subjects, however, subjects with the hypo-active NAcc had more severe depression symptoms.

Letizia Squarcina¹, Alberto De Luca², Marcella Bellani¹, Paolo Brambilla^3,4, Federico E Turkheimer⁵, and Alessandra Bertoldo^2
1Section of Psychiatry, AOUI Verona, Verona, VR, Italy, ²Department of Information Engineering, University of Padova, Padova, PD, Italy, ³University of Udine, Udine, UD, Italy, ⁴Dept. of Psychiatry and Behavioral Sciences, University of Texas Medical School, Houston, TX, United States, ⁵King's College London, London, United Kingdom

With this study, we used fractal geometry to analyze T1 data of patients affected by schizophrenia or bipolar disorder. We applied the box-count algorithm on segmented data and a modified, local version of it on non-segmented data, to compute fractal dimension both on the whole brain and in substructures. We found a marked difference on fractal dimension values in patients in respect to healthy controls. Fractal dimension is reduced in patients, with a visible effect especially in frontal lobe, which confirms previous findings of modification of this structures in these diseases.

Vanessa Wiggermann^1,2, Enedino Hernández Torres^1,3, Leonardo E. da Silveira⁴, Lakshmi N. Yatham⁴, and Alexander Rauscher^1,3
1Radiology, University of British Columbia, Vancouver, BC, Canada, ²Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada,³UBC MRI Research Centre, Vancouver, BC, Canada, ⁴Psychiatry, University of British Columbia, Vancouver, BC, Canada

Many psychiatric disorders are suggested to relate to metabolite changes and oxidative stress, which may be associated with iron accumulation in the brain. Here, we used susceptibility-sensitive gradient echo imaging to compare MR resonance frequency shifts and R2* relaxation rates in the deep brain gray matter between first episode mania patients and healthy controls. We found significant increases in MR resonance frequency in the caudate and the globus pallidus and a significant reduction in the ventral striatum in patients compared to controls. However, we observed no differences in R2* values between patients and healthy controls.

Casey P. Johnson¹, Robin L. Follmer², Ipek Oguz³, Lois A. Warren², Gary E. Christensen³, Jess G. Fiedorowicz², Vincent A. Magnotta^1,2, and John A. Wemmie^2,4
1Radiology, University of Iowa, Iowa City, IA, United States, ²Psychiatry, University of Iowa, Iowa City, IA, United States, ³Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, ⁴Veteran Affairs Hospital Center, Iowa City, IA, United States

We investigated the hypothesis that metabolism is abnormal in patients with bipolar disorder vs. normal controls using 3D quantitative T1ρ mapping. The T1ρ relaxation time has been shown to be sensitive to byproducts of metabolism including pH and metabolite concentrations. We observed that T1ρ is elevated in a euthymic case group, with evidence for a whole-brain difference as well as focal changes that exceed the global effect. This study furthers our understanding of bipolar disorder, identifies regions of interest to probe in future studies, and establishes T1ρ as a potential marker for abnormal metabolism in psychiatric diseases.

Wenjing Zhang¹, Su Lui¹, Wei Deng², Yao Li¹, Yuan Xiao¹, and Qiyong Gong^1
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China, ²Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, Sichuan, China

A multivariate pattern analysis was used to characterize structural and functional pattern implicated in antipsychotic-naïve patients with schizophrenia. The discriminating potential of structural neuroanatomy, functional activity and the combination of the both were compared with one another, and finally we found the combination of the two imaging modalities yield a highest accuracy. On this condition, further application of this approach with the integration of different parameters, such as cognitive, neuropathological and genetic information may be of great help in understanding the condition.

Hu Cheng¹, Sharlene Newman¹, Jerillyn S. Kent¹, Josselyn Howell¹, Amanda Bolbecker¹, Aina Puce¹, Brian F. O'Donnell¹, and William P. Hetrick^1
1Indiana University, Bloomington, IN, United States

Resting state functional networks with 278 cortical and subcortical nodes were constructed on 19 schizophrenics and 29 normal controls. By computing the nodal centrality of the resting state functional network, we show that the two groups can be differentiated using support vector machine based on the order of centrality for a certain number of nodes. The performance of the differentiation is better for the nodes with higher centrality in comparison to the same number of nodes with lower centrality. This finding indicates that change of network hubs may be associated with schizophrenia.

Anouk Marsman¹, Rene C.W. Mandl¹, Dennis W.J. Klomp², Marc M. Bohlken¹, Vincent O. Boer², Anna Andreychenko³, Wiepke Cahn¹, Rene S. Kahn¹, Peter R. Luijten², and Hilleke E. Hulshoff Pol^1
1Psychiatry, University Medical Center Utrecht, Utrecht, Netherlands, ²Radiology, University Medical Center Utrecht, Utrecht, Netherlands,³Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands

Schizophrenia is characterized by a loss of brain tissue, which may represent an ongoing pathophysiological process. The GABAergic and glutamatergic systems may be involved. Performing 1H-MRS at an ultra-high magnetic field strength of 7T results in increased sensitivity and spectral resolution, which is particularly important when measuring glutamate and GABA. We conducted a 7T 1H-MRS study to examine differences in GABA and glutamate levels between patients with schizophrenia and healthy controls. Prefrontal GABA/Cr ratios in patients were significantly lower as compared to controls. Moreover, prefrontal GABA/Cr ratios in patients were strongly associated with their level of general cognitive functioning.

Lijing Xin^1,2, Ralf Mekle³, Carina Ferrari^1,4, Philipp S. Baumann^1,4, Luis Alameda^1,4, Helene Moser¹, Margot Fournier^1,4, Huanxiang Lu⁵, Philippe Conus^4,6, Rolf Gruetter^2,7, and Kim Do^1,4
1Unit for Research in Schizophrenia, Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland, ²Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, ³Medical Physics, Physikalisch-Technische Bundesanstalt, Berlin, Germany, ⁴National Center of Competence in Research (NCCR) “SYNAPSY - The Synaptic Bases of Mental Diseases”, Lausanne, Switzerland, ⁵Institute of Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland, ⁶Service of General Psychiatry, Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland, ⁷Departments of Radiology, University of Geneva, Geneva, Switzerland

Impairment of glutathione (GSH) metabolism has been reported in schizophrenia patients. Moreover, the GAG trinucleotide repeat (TNR) polymorphisms in the gene coding for the catalytic (GCLC) subunit of the glutamate-cysteine ligase (GCL), the rate-limiting enzyme for GSH synthesis, are associated with schizophrenia in case-control studies. The present study measured GSH levels in the medial prefrontal cortex of patients in early phase of psychosis and controls using short TE MRS at 3T and showed for the first time that the GAG-TNR high-risk genotype of the GCLC gene predicts lower prefrontal GSH levels in vivo.

Anouk Schrantee¹, Lena Vaclavu¹, Dennis F R Heijtel¹, Matthan W A Caan¹, Jan Booij¹, Aart J Nederveen¹, and Liesbeth Reneman^1
1Academic Medical Center, Amsterdam, Netherlands

In this study we compared acute dextro-amphetamine (dAMPH)-induced changes in cerebral blood flow (CBF) as measured with a pCASL sequence between regular dAMPH users and healthy controls. In addition, dopamine release was measured using [¹²³I]IBZM SPECT. DAMPH administration decreased gray matter CBF in both groups. However, dAMPH induced increases in striatal CBF in controls, whereas this effect was blunted in dAMPH users. Furthermore, dopamine release was blunted in users compared to controls as measured with SPECT. These findings suggest a dysfunctional dopamine system in dAMPH users and also highlights the potential of phMRI to assess changes in dopamine neurotransmitter function.

Binu P Thomas^1,2, Kamakshi Gopal³, Mira D'Souza³, Deng Mao¹, and Hanzhang Lu^1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ²Department of Bioengineering, University of Texas Southwestern Medical Center/University of Texas at Arlington, Arlington, Texas, United States, ³Department of Speech and Hearing Sciences, University of North Texas, Denton, Texas, United States

Tinnitus is a condition that causes perception of sound in the absence of an auditory stimulus. Millions of people are affected by this and yet the pathophysiology is not well understood. Current consensus is that tinnitus originates in the brain, so we measured biomarkers of brain function using MRI. We found that when tinnitus patients heard tones, at the same frequency as their tinnitus, their brain showed hyper-activations in the frontal lobe compared to controls. Resting cerebral blood flow was lower in the tinnitus patients in the auditory cortex, indicating abnormal function. Thus, tinnitus patient’s brains are hyper-attentive to sound, while their auditory cortex showed diminished function.