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Bio

Bio


Dr. Haleh Karbasforoushan received her Master?s in Computer Science and Brain Modeling at University of Southern California. She then worked at UCLA and Vanderbilt University for a few years, studying brain morphological and functional changes in patients with Schizophrenia and children with Autism, using brain imaging methods. She then joined Northwestern University for her PhD studies in Neuroscience with a specialization in movement disorders. Her PhD research, funded by a NIH NRSA grant, used brain and spinal cord structural and functional MRI to investigate altered sensorimotor pathways involved in hand impairment post stroke. Dr. Karbasforoushan's research in stroke and psychiatric disorders have been published in journals such as Nature Communications and American Journal of Psychiatry. She currently is a post-doctoral research fellow at Stanford University and at VA Palo Alto. Her postdoctoral research, funded by a VA Polytrauma Advanced Fellowship, uses MRI and TMS techniques to investigate how brain stimulation can modulate brain functional activity and connectivity in treatment of traumatic brain injury and fibromyalgia.

Professional Education


  • Doctor of Philosophy, Northwestern University, Neuroscience
  • Master of Science, University of Southern California, Computer Science
  • Bachelor of Engineering, University of Science and Culture, Computer Engineering

Stanford Advisors


Publications

All Publications


  • Brainstem and spinal cord MRI identifies altered sensorimotor pathways post-stroke (vol 10, 3524, 2019) NATURE COMMUNICATIONS Karbasforoushan, H., Cohen-Adad, J., Dewald, J. A. 2020; 11 (1): 3433

    Abstract

    An amendment to this paper has been published and can be accessed via a link at the top of the paper.

    View details for DOI 10.1038/s41467-020-17024-8

    View details for Web of Science ID 000550668400001

    View details for PubMedID 32632101

    View details for PubMedCentralID PMC7338357

  • Limited capacity for ipsilateral secondary motor areas to support hand function post-stroke JOURNAL OF PHYSIOLOGY-LONDON Wilkins, K. B., Yao, J., Owen, M., Karbasforoushan, H., Carmona, C., Dewald, J. A. 2020; 598 (11): 2153?67

    Abstract

    Ipsilateral-projecting corticobulbar pathways, originating primarily from secondary motor areas, innervate the proximal and even distal portions, although they branch more extensively at the spinal cord. It is currently unclear to what extent these ipsilateral secondary motor areas and subsequent cortical projections may contribute to hand function following stroke-induced damage to one hemisphere. In the present study, we provide both structural and functional evidence indicating that individuals increasingly rely on ipsilateral secondary motor areas, although at the detriment of hand function. Increased activity in ipsilateral secondary motor areas was associated with increased involuntary coupling between shoulder abduction and finger flexion, most probably as a result of the low resolution of these pathways, making it increasingly difficult to open the hand. These findings suggest that, although ipsilateral secondary motor areas may support proximal movements, they do not have the capacity to support distal hand function, particularly for hand opening.Recent findings have shown connections of ipsilateral cortico-reticulospinal tract (CRST), predominantly originating from secondary motor areas to not only proximal, but also distal muscles of the arm. Following a unilateral stroke, CRST from the ipsilateral side remains intact and thus has been proposed as a possible backup system for post-stroke rehabilitation even for the hand. We argue that, although CRST from ipsilateral secondary motor areas can provide control for proximal joints, it is insufficient to control either hand or coordinated shoulder and hand movements as a result of its extensive spinal branching compared to contralateral corticospinal tract. To address this issue, we combined magnetic resonance imaging, high-density EEG, and robotics in 17 individuals with severe chronic hemiparetic stroke and 12 age-matched controls. We tested for changes in structural morphometry of the sensorimotor cortex and found that individuals with stroke demonstrated higher grey matter density in secondary motor areas ipsilateral to the paretic arm compared to controls. We then measured cortical activity when participants were attempting to generate hand opening either supported on a table or when lifting against a shoulder abduction load. The addition of shoulder abduction during hand opening increased reliance on ipsilateral secondary motor areas in stroke, but not controls. Crucially, the increased use of ipsilateral secondary motor areas was associated with decreased hand opening ability when lifting the arm as a result of involuntary coupling between the shoulder and wrist/finger flexors. Taken together, this evidence implicates a compensatory role for ipsilateral (i.e. contralesional) secondary motor areas post-stroke, although with no apparent capacity to support hand function.

    View details for DOI 10.1113/JP279377

    View details for Web of Science ID 000528549500001

    View details for PubMedID 32144937

    View details for PubMedCentralID PMC7266727

  • Brainstem and spinal cord MRI identifies altered sensorimotor pathways post-stroke NATURE COMMUNICATIONS Karbasforoushan, H., Cohen-Adad, J., Dewald, J. A. 2019; 10: 3524

    Abstract

    Damage to the corticospinal tract is widely studied following unilateral subcortical stroke, whereas less is known about changes to other sensorimotor pathways. This may be due to the fact that many studies investigated morphological changes in the brain, where the majority of descending and ascending brain pathways are overlapping, and did not investigate the brainstem where they separate. Moreover, these pathways continue passing through separate regions in the spinal cord. Here, using a high-resolution structural MRI of both the brainstem and the cervical spinal cord, we were able to identify a number of microstructurally altered pathways, in addition to the corticospinal tract, post stroke. Moreover, decreases in ipsi-lesional corticospinal tract integrity and increases in contra-lesional medial reticulospinal tract integrity were correlated with motor impairment severity in individuals with stroke.

    View details for DOI 10.1038/s41467-019-11244-3

    View details for Web of Science ID 000478867500009

    View details for PubMedID 31388003

    View details for PubMedCentralID PMC6684621

  • Intrainsular connectivity and somatosensory responsiveness in young children with ASD MOLECULAR AUTISM Failla, M. D., Peters, B. R., Karbasforoushan, H., Foss-Feig, J. H., Schauder, K. B., Heflin, B. H., Cascio, C. J. 2017; 8: 25

    Abstract

    The human somatosensory system comprises dissociable paths for discriminative and affective touch, reflected in separate peripheral afferent populations and distinct cortical targets. Differences in behavioral and neural responses to affective touch may have an important developmental role in early social experiences, which are relevant for autism spectrum disorder (ASD).Using probabilistic tractography, we compared the structural integrity of white matter pathways for discriminative and affective touch in young children with ASD and their typically developing (TD) peers. We examined two tracts: (1) a tract linking the thalamus with the primary somatosensory cortex, which carries discriminative tactile information, and (2) a tract linking the posterior insula-the cortical projection target of unmyelinated tactile afferents mediating affective touch-with the anterior insula, which integrates sensory and visceral inputs to interpret emotional salience of sensory stimuli. We investigated associations between tract integrity and performance on a standardized observational assessment measuring tactile discrimination and affective responses to touch.Both the thalamocortical and intrainsular tracts showed reduced integrity (higher mean diffusivity) in the ASD group compared to those in the TD group. Consistent with the previous findings, the ASD group exhibited impaired tactile discriminative ability, more tactile defensiveness, and more sensory seeking (e.g., enthusiastic play or repetitive engagement with a specific tactile stimulus). There was a significant relation between intrainsular tract integrity and tactile seeking. The direction of this relation differed between groups: higher intrainsular mean diffusivity (MD) (reflecting decreased tract integrity) was associated with increased tactile seeking in the TD group but with decreased tactile seeking in the ASD group. In the TD group, decreased tactile defensiveness was also associated with higher intrainsular MD, but there was no relation in the ASD group. Discriminative touch was not significantly associated with integrity of either tract in either group.These results support previous findings suggesting a central role for the insula in affective response to touch. While both discriminative and affective touch and both somatosensory tracts are affected in ASD, the restriction of brain-behavior associations to the intrainsular tract and tactile seeking suggests more complex and perhaps higher-order influence on differences in tactile defensiveness and discrimination.

    View details for DOI 10.1186/s13229-017-0143-y

    View details for Web of Science ID 000403304500001

    View details for PubMedID 28630661

    View details for PubMedCentralID PMC5470196

  • Processing speed impairment in schizophrenia is mediated by white matter integrity PSYCHOLOGICAL MEDICINE Karbasforoushan, H., Duffy, B., Blackford, J. U., Woodward, N. D. 2015; 45 (1): 109-120

    Abstract

    Processing speed predicts functional outcome and is a potential endophenotype for schizophrenia. Establishing the neural basis of processing speed impairment may inform the treatment and etiology of schizophrenia. Neuroimaging investigations in healthy subjects have linked processing speed to brain anatomical connectivity. However, the relationship between processing speed impairment and white matter (WM) integrity in schizophrenia is unclear.Individuals with schizophrenia and healthy subjects underwent diffusion tensor imaging (DTI) and completed a brief neuropsychological assessment that included measures of processing speed, verbal learning, working memory and executive functioning. Group differences in WM integrity, inferred from fractional anisotropy (FA), were examined throughout the brain and the hypothesis that processing speed impairment in schizophrenia is mediated by diminished WM integrity was tested.WM integrity of the corpus callosum, cingulum, superior and inferior frontal gyri, and precuneus was reduced in schizophrenia. Average FA in these regions mediated group differences in processing speed but not in other cognitive domains. Diminished WM integrity in schizophrenia was accounted for, in large part, by individual differences in processing speed.Cognitive impairment in schizophrenia was mediated by reduced WM integrity. This relationship was strongest for processing speed because deficits in working memory, verbal learning and executive functioning were not mediated by WM integrity. Larger sample sizes may be required to detect more subtle mediation effects in these domains. Interventions that preserve WM integrity or ameliorate WM disruption may enhance processing speed and functional outcome in schizophrenia.

    View details for DOI 10.1017/S0033291714001111

    View details for Web of Science ID 000349616800009

    View details for PubMedID 25066842

    View details for PubMedCentralID PMC5297385

  • Dorsal Raphe Functional Connectivity in Depression Weinstein, J. J., Rogers, B. P., Taylor, W. D., Boyd, B. D., Karbasforoushan, H., Cowan, R. L., Salomon, R. M. ELSEVIER SCIENCE INC. 2014: 368S
  • Processing Speed Impairment in Schizophrenia is Mediated by White Matter Integrity Karbasforoushan, H., Duffy, B., Blackford, J. U., Woodward, N. D. ELSEVIER SCIENCE INC. 2014: 112S
  • Response selection impairment in schizophrenia transcends sensory and motor modalities. Schizophrenia research Woodward, N. D., Duffy, B., Karbasforoushan, H. 2014; 152 (2-3): 446-9

    Abstract

    Response selection dysfunction contributes to processing speed impairment in schizophrenia. However, it is unclear if response selection impairment transcends sensory and motor modalities or is modality specific. To address this question, healthy subjects and individuals with schizophrenia completed reaction time (RT) experiments with different combinations of sensory cues (i.e. visual, auditory) and motor response (i.e. manual, vocal). We found that response selection impairment in schizophrenia was present regardless of the sensory and motor modality of the tasks and correlated with performance on neuropsychological tests of processing speed. These results implicate dysfunction of amodal response selection brain regions in schizophrenia. Interventions that reduce the length of response selection stage processing may improve processing speed in schizophrenia.

    View details for DOI 10.1016/j.schres.2013.11.038

    View details for PubMedID 24361304

    View details for PubMedCentralID PMC3925400

  • Functional Dysconnectivity in Schizophrenia Transcends Cognitive State Karbasforoushan, H., Duffy-Alberto, B., Rogers, B. P., Woodward, N. D. ELSEVIER SCIENCE INC. 2013: 302S-303S
  • Prefrontal cortex activity during response selection predicts processing speed impairment in schizophrenia. Journal of the International Neuropsychological Society : JINS Woodward, N. D., Duffy, B., Karbasforoushan, H. 2013; 19 (7): 782-91

    Abstract

    Processing speed is the most impaired neuropsychological domain in schizophrenia and a robust predictor of functional outcome. Determining the specific cognitive operations underlying processing speed dysfunction and identifying their neural correlates may assist in developing pro-cognitive interventions. Response selection, the process of mapping stimuli onto motor responses, correlates with neuropsychological tests of processing speed and may contribute to processing speed impairment in schizophrenia. This study investigated the relationship between behavioral and neural measures of response selection, and a neuropsychological index of processing speed in schizophrenia. Twenty-six patients with schizophrenia and 21 healthy subjects underwent functional magnetic resonance imaging scanning during performance of two- and four-choice reaction time (RT) tasks and completed the Wechsler Adult Intelligence Scale-III (WAIS) Processing Speed Index (PSI). Response selection, defined as RT slowing between two- and four-choice RT, was impaired in schizophrenia and correlated with psychometric processing speed. Greater activation of the dorsolateral prefrontal cortex (PFC) was observed in schizophrenia and correlated with poorer WAIS PSI scores. Deficient response selection and abnormal recruitment of the dorsolateral PFC during response selection contribute to processing speed impairment in schizophrenia. Interventions that improve response selection and normalize dorsolateral PFC function may improve processing speed in schizophrenia.

    View details for DOI 10.1017/S1355617713000532

    View details for PubMedID 23816240

    View details for PubMedCentralID PMC3910268

  • Resting-State Networks in Schizophrenia CURRENT TOPICS IN MEDICINAL CHEMISTRY Karbasforoushan, H., Woodward, N. D. 2012; 12 (21): 2404-2414

    Abstract

    Schizophrenia has been conceptualized as a disorder of altered brain connectivity (i.e. dysconnectivity). Until relatively recently, it was not feasible to test dysconnectivity hypotheses of schizophrenia in vivo. Resting-state functional magnetic resonance imaging (fMRI) is a powerful tool for mapping functional networks of the brain, such as the default mode network (DMN), and investigating the systems-level pathology of neurological and psychiatric disorders. In this article, we review the latest findings from resting-state fMRI studies on schizophrenia. Despite the wide array of methods used and heterogeneity of patient samples, several tentative conclusions may be drawn from the existing literature. 1) Connectivity of the DMN is altered in schizophrenia. Findings vary across studies; however, a majority of investigations reported hyper-connectivity of the DMN. 2) Resting-state connectivity of the prefrontal cortex (PFC) is reduced in schizophrenia, particularly intra-PFC connectivity. 3) Cortical-subcortical networks, including thalamocortical, frontolimbic, and cortico-cerebellar networks are altered in schizophrenia. 4) Preliminary findings indicate that functional connectivity within auditory/language networks and the basal ganglia is related to specific clinical symptoms, including auditory- verbal hallucinations and delusions. 5) Whole-brain network topology measures based on graph theory indicate that functional brain networks in schizophrenia are characterized by reduced small-worldness, lower degree connectivity of brain hubs, and decreased modularity. 6) Some of the alterations in functional connectivity observed in probands are present in unaffected relatives, raising the possibility that functional dysconnectivity is an endophenotype related to genetic risk for schizophrenia. Combined, these findings provide broad support for dysconnectivity theories of schizophrenia. We conclude our review with a discussion of the limitations of the existing literature and potentially important areas of future research.

    View details for DOI 10.2174/156802612805289863

    View details for Web of Science ID 000315195300011

    View details for PubMedID 23279179

  • Interhemispheric Functional Connectivity During Resting-State is Reduced in Schizophrenia Karbasforoushan, H., Heckers, S., Woodward, N. D. ELSEVIER SCIENCE INC. 2012: 269S
  • Thalamocortical dysconnectivity in schizophrenia. The American journal of psychiatry Woodward, N. D., Karbasforoushan, H., Heckers, S. 2012; 169 (10): 1092-9

    Abstract

    The thalamus and cerebral cortex are connected via topographically organized, reciprocal connections. Previous studies have revealed thalamic abnormalities in schizophrenia; however, it is not known whether thalamocortical networks are differentially affected in the disorder. To explore this possibility, the authors examined functional connectivity in intrinsic low-frequency blood-oxygen-level-dependent (BOLD) signal fluctuations between major divisions of the cortex and thalamus using resting-state functional MRI (fMRI).Seventy-seven healthy subjects and 62 patients with schizophrenia underwent resting-state fMRI. To identify functional subdivisions of the thalamus, the authors parceled the cortex into six regions of interest: the prefrontal cortex, motor cortex/supplementary motor area, somatosensory cortex, temporal lobe, posterior parietal cortex, and occipital lobe. Mean BOLD time series were extracted for each region of interest and entered into a seed-based functional connectivity analysis.Consistent with previous reports, activity in distinct cortical areas correlated with specific, largely nonoverlapping regions of the thalamus in both healthy comparison subjects and schizophrenia patients. Direct comparison between groups revealed reduced prefrontal-thalamic connectivity and increased motor/somatosensory-thalamic connectivity in schizophrenia. The changes in connectivity were unrelated to local gray matter content within the thalamus and to antipsychotic medication dosage. No differences were observed in temporal, posterior parietal, or occipital cortex connectivity with the thalamus.These findings establish differential abnormalities of thalamocortical networks in schizophrenia. The etiology of schizophrenia may disrupt the development of prefrontal-thalamic connectivity and refinement of somatomotor connectivity with the thalamus that occurs during brain maturation.

    View details for DOI 10.1176/appi.ajp.2012.12010056

    View details for PubMedID 23032387

    View details for PubMedCentralID PMC3810300

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