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308 results on '"Ashtari, Manzar"'

55. Increase in caudate nuclei volumes of first-episode schizophrenic patients taking antipsychotic drugs

Author

Chakos, Miranda H., Lieberman, Jeffrey A., Bilder, Robert M., Borenstein, Michael, Lerner, Gail, Bogerts, Bernhard, Wu, Houwei, Kinon, Bruce, and Ashtari, Manzar

Subjects
Schizophrenia -- Research, Antipsychotic drugs -- Adverse and side effects, Health, Psychology and mental health
Abstract

Objective: This study examined the pathomorphology of the caudate nuclei in first-episode schizophrenic patients with minimal previous neuroleptic exposure. Method: Magnetic resonance imaging (MRI) of the brain was used to examine longitudinally the caudate pathomorphology in 29 first-episode schizophrenic patients and 10 healthy comparison subjects. MRI scans were obtained after the subjects entered the study and at 18-month follow-up. The patients were treated with standardized neuroleptic regimens during the 18-month period. Volumetric assessments of the cerebral cortex, lateral ventricles, and caudate nuclei were performed on [T.sub.1]-weighted coronal brain sections. In addition, the patients were systematically evaluated for psychopathology at baseline and during treatment. Results: Caudate volumes increased 5.7% in the patients during the 18-month treatment interval, whereas they decreased 1.6% in the comparison subjects over the same time period. Greater amounts of antipsychotic medication received by patients before the first scan and younger age at the time of the first scan were associated with larger increases in caudate volume. Conclusions: Caudate enlargement occurs early in the course of treatment in young first-episode schizophrenic patients. This may be a result of an interaction between neuroleptic treatment and the plasticity of dopaminergic neuronal systems in young patients.

Published
1994

56. Absence of regional hemispheric volume asymmetries in first-episode schizophrenia

Author

Bilder, Robert M., Wu, Houwei, Bogerts, Bernhard, Degreef, Gustav, Ashtari, Manzar, Alvir, Jose M.J., Snyder, Peter J., and Lieberman, Jeffrey A.

Subjects
Schizophrenia -- Research, Health, Psychology and mental health
Abstract

The goal of this study was to determine whether patients experiencing their first episode of schizophrenia differ from healthy subjects in regional cerebral hemispheric volumes or asymmetries. Method: Regional volumes corresponding to prefrontal, premotor, sensorimotor, occipitoparietal, and temporal lobes in each hemisphere were measured on contiguous coronal magnetic resonance images in 70 patients experiencing their first episode of schizophrenia and in 51 healthy comparison subjects. Results: Patients did not differ from the comparison subjects in regional or total hemispheric volumes, but they had abnormal hemispheric asymmetries. Subjects in the comparison group had significant lateral asymmetries in each region: their occipitoparietal and sensorimotor regions were larger on the left, and their pre-motor, prefrontal, and temporal regions were larger on the right. Patients lacked lateral asymmetries and showed significantly less asymmetry than healthy subjects in occipitoparietal, premotor, and prefrontal regions. Absence of the normal asymmetry was more common among patients initially diagnosed with the undifferentiated than with the paranoid subtype of schizophrenia and was associated with more severe negative symptoms among men. Asymmetries were related to sex and handedness regardless of diagnosis; specifically, dextral men showed more asymmetry than nondextral men or dextral women. Conclusions: The absence of normal hemispheric asymmetries suggests an anomaly in the development of laterally specialized cerebral systems in schizophrenia, and this may be associated with an initial presentation of nonparanoid psychosis.

Published
1994

57. Prospective Study of Psychobiology in First-Episode Schizophrenia at Hillside Hospital

Author

Lieberman, Jeffrey A., Alvir, Jose Ma. J., Woerner, Margaret, Degreef, Gustav, Bilder, Robert M., Ashtari, Manzar, Bogerts, Bernhard, Mayerhoff, David I., Geisler, Stephen H., Loebel, Antony, Levy, Deborah L., Hinrichsen, Gregory, Szymanski, Sally, Chakos, Miranda, Koreen, Amy, Borenstein, Michael, and Kane, John M.

Published
1992

63. The Role of the Human Visual Cortex in Assessment of the Long-Term Durability of Retinal Gene Therapy in Follow-on RPE65 Clinical Trial Patients

Author

Ashtari, Manzar, primary, Nikonova, Elena S., additional, Marshall, Kathleen A., additional, Young, Gloria J., additional, Aravand, Puya, additional, Pan, Wei, additional, Ying, Gui-shuang, additional, Willett, Aimee E., additional, Mahmoudian, Mani, additional, Maguire, Albert M., additional, and Bennett, Jean, additional

Published
2017
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67. Plasticity of the human visual system after retinal gene therapy in patients with Leber’s congenital amaurosis

Author

Ashtari, Manzar, primary, Zhang, Hui, additional, Cook, Philip A., additional, Cyckowski, Laura L., additional, Shindler, Kenneth S., additional, Marshall, Kathleen A., additional, Aravand, Puya, additional, Vossough, Arastoo, additional, Gee, James C., additional, Maguire, Albert M., additional, Baker, Chris I., additional, and Bennett, Jean, additional

Published
2015
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68. Mapping the Functional Anatomy of Sentence Comprehension and Application to Presurgical Evaluation of Patients with Brain Tumor

Author

Ashtari, Manzar, Perrine, Kenneth, Elbaz, Rania, Syed, Uzma, Thaden, Emily, McIlree, Carolyn, Dolgoff-Kaspar, Rima, Clarke, Tana, Diamond, Alan, and Ettinger, Alan

Subjects
Adult, Male, Brain Mapping, Reading, Brain Neoplasms, Preoperative Care, Brain, Humans, Female, Comprehension, behavioral disciplines and activities, psychological phenomena and processes
Abstract

BACKGROUND AND PURPOSE: The main clinical indication for functional MR imaging (fMRI) has been to preoperatively map the cortex. Motor paradigms to activate the cortex are simple and robust; however, language tasks show greater variability and difficulty. The aim of this study was to develop a language task with an adequate control task to engage the areas of the posterior temporal lobe responsible for sentence comprehension. METHODS: We performed a cloze paradigm requiring silent reading of a visually presented sentence-completion task based on semantic meaning versus a letter-scanning epoch requiring the completion of nonlinguistic strings or a rest period. Before this task was clinically used in two patients epilepsy and cavernous angioma, its feasibility and accuracy were tested in 14 healthy right-handed participants. RESULTS: Results showed significant activation of the posterior temporal cortex, including a broad area across the posterior left temporal cortex extending into the inferior parietal lobule. When the sentence completion–minus-letter string task was compared with the sentence completion–minus-rest task, increased activation was present in the posterior temporal lobe. CONCLUSION: Decreased significant activation during the sentence completion–minus-rest contrast may be attributed to increased noise from intersubject variability in the rest period. Our results suggest that this task elucidates areas important to reading comprehension in the posterior and inferior temporal regions that verbal fluency and auditory discrimination tasks do not. Data from two cases are summarized to exemplify the input of this task for neurosurgery.

Published
2005

69. Cortical parcellation for neonatal brains

Author

Wu, Jue, primary, Ashtari, Manzar, additional, Betancourt, Laura M., additional, Brodsky, Nancy L., additional, Giannetta, Joan M., additional, Gee, James C., additional, Hurt, Hallam, additional, and Avants, Brian B., additional

Published
2014
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71. AAV2 Gene Therapy Readministration in Three Adults with Congenital Blindness

Author

Bennett, Jean, primary, Ashtari, Manzar, additional, Wellman, Jennifer, additional, Marshall, Kathleen A., additional, Cyckowski, Laura L., additional, Chung, Daniel C., additional, McCague, Sarah, additional, Pierce, Eric A., additional, Chen, Yifeng, additional, Bennicelli, Jeannette L., additional, Zhu, Xiaosong, additional, Ying, Gui-shuang, additional, Sun, Junwei, additional, Wright, J. Fraser, additional, Auricchio, Alberto, additional, Simonelli, Francesca, additional, Shindler, Kenneth S., additional, Mingozzi, Federico, additional, High, Katherine A., additional, and Maguire, Albert M., additional

Published
2012
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78. Clinical and Neuropsychological Correlates of White Matter Abnormalities in Recent Onset Schizophrenia

Author

Szeszko, Philip R, primary, Robinson, Delbert G, additional, Ashtari, Manzar, additional, Vogel, Joshua, additional, Betensky, Julia, additional, Sevy, Serge, additional, Ardekani, Babak A, additional, Lencz, Todd, additional, Malhotra, Anil K, additional, McCormack, Joanne, additional, Miller, Rachel, additional, Lim, Kelvin O, additional, Gunduz-Bruce, Handan, additional, Kane, John M, additional, and Bilder, Robert M, additional

Published
2007
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81. Brain morphometry using diffusion-weighted magnetic resonance imaging: application to schizophrenia

Author

Ardekani, Babak A., primary, Bappal, Arthika, additional, D'Angelo, Debra, additional, Ashtari, Manzar, additional, Lencz, Todd, additional, Szeszko, Philip R., additional, Butler, Pamela D., additional, Javitt, Daniel C., additional, Lim, Kelvin O., additional, Hrabe, Jan, additional, Nierenberg, Jay, additional, Branch, Craig A., additional, and Hoptman, Matthew J., additional

Published
2005
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82. Attention-deficit/hyperactivity disorder: A preliminary diffusion tensor imaging study

Author

Ashtari, Manzar, primary, Kumra, Sanjiv, additional, Bhaskar, Shree L., additional, Clarke, Tana, additional, Thaden, Emily, additional, Cervellione, Kelly L., additional, Rhinewine, Joseph, additional, Kane, John M., additional, Adesman, Andrew, additional, Milanaik, Ruth, additional, Maytal, Joseph, additional, Diamond, Alan, additional, Szeszko, Philip, additional, and Ardekani, Babak A., additional

Published
2005
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88. Safety and durability of effect of contralateral-eye administration of AAV2 gene therapy in patients with childhood-onset blindness caused by RPE65mutations: a follow-on phase 1 trial

Author

Bennett, Jean, Wellman, Jennifer, Marshall, Kathleen A, McCague, Sarah, Ashtari, Manzar, DiStefano-Pappas, Julie, Elci, Okan U, Chung, Daniel C, Sun, Junwei, Wright, J Fraser, Cross, Dominique R, Aravand, Puya, Cyckowski, Laura L, Bennicelli, Jeannette L, Mingozzi, Federico, Auricchio, Alberto, Pierce, Eric A, Ruggiero, Jason, Leroy, Bart P, Simonelli, Francesca, High, Katherine A, and Maguire, Albert M

Abstract

Safety and efficacy have been shown in a phase 1 dose-escalation study involving a unilateral subretinal injection of a recombinant adeno-associated virus (AAV) vector containing the RPE65gene (AAV2-hRPE65v2) in individuals with inherited retinal dystrophy caused by RPE65mutations. This finding, along with the bilateral nature of the disease and intended use in treatment, prompted us to determine the safety of administration of AAV2-hRPE65v2 to the contralateral eye in patients enrolled in the phase 1 study.

Published
2016
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90. Low-Dose Spiral Computed Tomography of the Thorax

Author

TAKAHASHI, MASASHI, primary, MAGUIRE, WILLIAM M., additional, ASHTARI, MANZAR, additional, KHAN, ARFA, additional, PAPP, ZSUZSANNA, additional, ALBERICO, RONALD, additional, CAMPBELL, WALTER, additional, EACOBACCI, THERESA, additional, and HERMAN, PETER G., additional

Published
1998
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99. Resolving axon fiber crossings at clinical b-values: An evaluation study.

Author

Ramirez-Manzanares, Alonso, Cook, Philip A., Hall, Matt, Ashtari, Manzar, and Gee, James C.

Subjects
MAGNETIC resonance imaging of the brain, AXONS, DENSITY functionals, ESTIMATION theory, ALGORITHMS, SIGNAL-to-noise ratio, MEDICAL statistics
Abstract

Purpose: Diffusion tensor magnetic resonance imaging is widely used to study the structure of the fiber pathways of brain white matter. However, the diffusion tensor cannot capture complex intravoxel fiber architecture such as fiber crossings of bifurcations. Consequently, a number of methods have been proposed to recover intravoxel fiber bundle orientations from high angular resolution diffusion imaging scans, optimized to resolve fiber crossings. It is important to improve the brain tractography by applying these multifiber methods to diffusion tensor protocols with a clinical b- value (low), which are optimized on computing tensor scalar statistics. In order to characterize the variance among different methods, consequently to be able to select the most appropriate one for a particular application, it is desirable to compare them under identical experimental conditions. Methods: In this work, the authors study how QBall, spherical deconvolution, persistent angular structure, stick and ball, diffusion basis functions, and analytical QBall methods perform under clinically-realistic scanning conditions, where the b-value is typically lower (around 1000 s/mm2), and the number of diffusion encoding orientations is fewer (30-60) than in dedicated high angular resolution diffusion imaging scans. To characterize the performance of the methods, they consider the accuracy of the estimated number of fibers, the relative contribution of each fiber population to the total magnetic resonance signal, and the recovered orientation error for each fiber bundle. To this aim, they use four different sources of data: synthetic data from Gaussian mixture model, cylinder restricted model, and in vivo data from two different acquisition schemes. Results: Results of their experiments indicate that: (a) it is feasible to apply only a subset of these methods to clinical data sets and (b) it allows one to characterize the performance of each method. In particular, two methods are not feasible to the kind of magnetic resonance diffusion data they test. By the characterization of their systematic behavior, among other conclusions, they report the method which better performs for the estimation of the number of diffusion peaks per voxel, also the method which better estimates the diffusion orientation. Conclusions: The framework they propose for comparison allows one to effectively characterize and compare the performance of the most frequently used multifiber algorithms under realistic medical settings and realistic signal-to-noise ratio environments. The framework is based on several crossings with a non-orientational bias and different signal models. The results they present are relevant for medical doctors and researchers, interested in the use of the multifiber solution for tractography. [ABSTRACT FROM AUTHOR]

Published
2011
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