Role Of fMRI Research Articles

The difference of functional MR imaging in evaluating outcome of patients with diffuse and compact brain arteriovenous malformation.

Microsurgical resection is an effective method to treat brain arteriovenous malformations (BAVMs). Functional magnetic resonance imaging (fMRI) can evaluate the spatial relationship of nidus and eloquent. Diffuse BAVMs are related to poor outcomes postoperatively. The role of fMRI in evaluating outcomes in patients with different nidus types remains unclear. BAVM patients received microsurgical resection were included from a prospective, multicenter cohort study. All patients underwent fMRI evaluation preoperatively and were regularly followed up postoperatively. Diffuse BAVM is radiologically identified as nidus containing normal brain tissue interspersing between malformed vessels. Lesion-to-eloquent distance (LED) was calculated based on the relationship between nidus and eloquent. The primary outcome was 180-day unfavorable neurological status postoperatively. The risk of primary outcome was investigated within different BAVM nidus types. The LED's performance to predict poor outcome was evaluated using area under curve (AUC). 346 BAVM patients were included in this study. 93 (26.9%) patients were found to have a 180-day unfavorable outcome. Multivariate logistic analysis demonstrated LED (odd ratio [OR], 0.44; 0.34-0.57; P < 0.001) and mRS at admission (OR, 2.59; 1.90-3.54; P < 0.001) as factors of unfavorable outcome. Subgroup analysis showed LED and mRS at admission as factors of unfavorable outcome for patients with compact BAVMs (all P < 0.05), but not for patients with diffuse BAVMs. Subsequent analysis showed that LED performed poorly to predict the unfavorable outcome for patients with diffuse BAVMs, compared with patients with compact BAVMs (AUC as 0.69 vs. 0.86, P < 0.05). A larger cutoff value of LED to unfavorable outcome was found in patients with diffuse BAVMs (15mm) compared with patients with compact BAVMs (4.7mm). Usage of LED to evaluate postoperative outcome of patients with diffuse BAVMs differs from its use in patients with compact BAVMs. Specific assessment strategy considering BAVM nidus types could help improve patients' outcome. MITASREAVM cohort (unique identifier: NCT02868008, https://clinicaltrials.gov/study/NCT02868008?term=NCT02868008&rank=1 ).

Functional MRI (fMRI) Evaluation of Hyperbaric Oxygen Therapy (HBOT) Efficacy in Chronic Cerebral Stroke: A Small Retrospective Consecutive Case Series.

Topics: Functional Magnetic Resonance Imaging (fMRI) evaluation of HyberBaric Oxygen Therapy (HBOT) effects on chronic cerebral stroke Patients (Pts). Introduction: Our aim was to evaluate with fMRI, in a 3 Tesla system, the functional effects of HBOT on the Central Nervous System (CNS) in four Pts with established ischaemic and haemorrhagic cerebral strokes (2 Pts each). To our knowledge, no author used fMRI technique for this purpose, till now. Methods: All four Pts underwent a fMRI study before and after 40 HBOT sessions, with a time window of a few days. They carried out two language (text listening, silent word-verb generation) and two motor (hand and foot movements) tasks (30 s On-Off block paradigms). Results: After HBOT, all Pts reported a clinical improvement, mostly concerning language fluency and motor paresis. fMRI analysis demonstrated an increase in both the extent and the statistical significance of most of the examined eloquent areas. Conclusions: These changes were consistent with the clinical improvement in all Pts, suggesting a possible role of fMRI in revealing neuronal functional correlates of neuronal plasticity and HBOT-related neoangiogenesis. Although only four Pts were examined, fMRI proved to be a sensitive, non-invasive and reliable modality for monitoring neuronal functional changes before and after HBOT.

The Use of Functional Magnetic Resonance Imaging to Test Pharmacotherapies for Alcohol Use Disorder: A Systematic Review.

Alcohol use disorder (AUD) is a chronic relapsing condition that represents a significant public health concern. Pharmacological treatment development for AUD is a top research priority, and many studies are being conducted to evaluate potential AUD treatments. Understanding the brain circuitry impacted by addiction is crucial for the development of efficacious pharmacological interventions. These neuroadaptations can be probed noninvasively using functional magnetic resonance neuroimaging (fMRI). fMRI may be an effective tool to identify biomarkers for AUD pharmacotherapies, evaluating changes associated with pharmacological treatment. Thus, the present qualitative review of the literature focuses on the role of fMRI as a tool for medication development for AUD. The aim of this review was to assemble research across a range of fMRI paradigms to study the effectiveness of pharmacological treatments of adult AUD. First, we present a qualitative review of fMRI AUD pharmacotherapy studies, differentiating studies based on their dosing regimen. Second, we provide recommendations for the field to improve the use of fMRI as a biomarker for AUD pharmacotherapy.

The Role of fMRI in the Assessment of Neuroplasticity in MS: A Systematic Review

Neuroplasticity, which is the ability of the brain to adapt to internal and external environmental changes, physiologically occurs during growth and in response to damage. The brain's response to damage is of particular interest in multiple sclerosis, a chronic disease characterized by inflammatory and neurodegenerative damage to the central nervous system. Functional MRI (fMRI) is a tool that allows functional changes related to the disease and to its evolution to be studied in vivo. Several studies have shown that abnormal brain recruitment during the execution of a task starts in the early phases of multiple sclerosis. The increased functional activation during a specific task observed has been interpreted mainly as a mechanism of adaptive plasticity designed to contrast the increase in tissue damage. More recent fMRI studies, which have focused on the activity of brain regions at rest, have yielded nonunivocal results, suggesting that changes in functional brain connections represent mechanisms of either adaptive or maladaptive plasticity. The few longitudinal studies available to date on disease evolution have also yielded discrepant results that are likely to depend on the clinical features considered and the length of the follow-up. Lastly, fMRI has been used in interventional studies to investigate plastic changes induced by pharmacological therapy or rehabilitation, though whether such changes represent a surrogate of neuroplasticity remains unclear. The aim of this paper is to systematically review the existing literature in order to provide an overall description of both the neuroplastic process itself and the evolution in the use of fMRI techniques as a means of assessing neuroplasticity. The quantitative and qualitative approach adopted here ensures an objective analysis of published, peer-reviewed research and yields an overview of up-to-date knowledge.

Surgical Resection of Insular Gliomas and Roles of Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging Tractography—Single Surgeon Experience

In gliomas located in proximity to eloquent areas, near total resection and subsequent radiotherapy is often preferred to avoid postoperative neurologic complications. Preoperative functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) tractography provide new insights into surgeries of insular gliomas. In this study we report our experience of surgical management of insular gliomas and the role of fMRI and DTI tractography in planning the resection. We retrospectively compared the clinical and outcome variables of 61 patients who underwent surgical resection of insular gliomas. The study population was divided into 2 groups according to the use of fMRI and DTI tractography in planning the resection. The average age of the study population was 44.1 ± 12.6 years with 21 (34.4%) of the patients women. Nearly two thirds of them (40, or 65.6%) had World Health Organization grade II tumors, and 16 patients (26.2%) had grade IV tumors. The most common tumor was glioblastoma, observed in 16 patients (26.2%). In 10 (16.4%) patients, fMRI and DTI tractography were used. The overall mortality in the study population was 15 (24.6%). None of the patients where fMRI and DTI were used for planning the surgery died (29.4% vs. 0.0%; P= 0.05), and all of them had normal functioning (70.5% vs. 100.0%; P= 0.05) at 3 months' follow-up. Surgical resection of insular gliomas remains a challenge to the neurosurgeon and demands good knowledge of anatomic landmarks. Use of fMRI and DTI tractography may help achieve a good outcome.

Parametric fMRI of paced motor responses uncovers novel whole-brain imaging biomarkers in spinocerebellar ataxia type 3.

Machado-Joseph Disease, inherited type 3 spinocerebellar ataxia (SCA3), is the most common form worldwide. Neuroimaging and neuropathology have consistently demonstrated cerebellar alterations. Here we aimed to discover whole-brain functional biomarkers, based on parametric performance-level-dependent signals. We assessed 13 patients with early SCA3 and 14 healthy participants. We used a combined parametric behavioral/functional neuroimaging design to investigate disease fingerprints, as a function of performance levels, coupled with structural MRI and voxel-based morphometry. Functional magnetic resonance imaging (fMRI) was designed to parametrically analyze behavior and neural responses to audio-paced bilateral thumb movements at temporal frequencies of 1, 3, and 5 Hz. Our performance-level-based design probing neuronal correlates of motor coordination enabled the discovery that neural activation and behavior show critical loss of parametric modulation specifically in SCA3, associated with frequency-dependent cortico/subcortical activation/deactivation patterns. Cerebellar/cortical rate-dependent dissociation patterns could clearly differentiate between groups irrespective of grey matter loss. Our findings suggest functional reorganization of the motor network and indicate a possible role of fMRI as a tool to monitor disease progression in SCA3. Accordingly, fMRI patterns proved to be potential biomarkers in early SCA3, as tested by receiver operating characteristic analysis of both behavior and neural activation at different frequencies. Discrimination analysis based on BOLD signal in response to the applied parametric finger-tapping task significantly often reached >80% sensitivity and specificity in single regions-of-interest.Functional fingerprints based on cerebellar and cortical BOLD performance dependent signal modulation can thus be combined as diagnostic and/or therapeutic targets in hereditary ataxia. Hum Brain Mapp 37:3656-3668, 2016. © 2016 Wiley Periodicals, Inc.

The role of fMRI in detecting attitude toward brand switching: an exploratory study using high technology products

Purpose The purpose of this paper is to investigate the factors that underpin consumer attitude toward switching a product brand, using functional magnetic resonance imaging (fMRI) to study brain activity during the decision-making process. Most of the literature shows that in the past, conventional marketing research approaches have been used to study brand switching among consumers. However, there is a lack of understanding of the importance of evaluating brain activations during the decision-making process when a consumer is selecting a brand. Design/methodology/approach The proposed model is a simplified version of consumer acceptance of technology model. This model accounts for cognitive and affect factors when choosing a product by including perceived usefulness and pleasure variables, respectively. An event-related fMRI experiment was designed and conducted using two smartphone brands. Findings The level of brain activation at the ventromedial prefrontal cortex (vmPFC) increased when participants were asked to judge images that reflect brand perceived usefulness compared with judging images that reflect brand pleasure. Similarly, the higher the perceived usefulness of the other smartphone, the greater the activation of the vmPFC during decision-making to switch to that smartphone. Practical Implications This study contributes to the literature on brand switching by exploring the importance of fMRI technique in evaluating brain activities during decision-making to adopt a brand. For managers, research findings would allow them to draft better marketing and advertisement strategies that enhance consumer perception value of high technology brands and positive emotional experience. Originality/value Although the literature reports considerable research on brand switching, this is the first exploratory study to utilize fMRI to investigate consumer attitude toward switching. In addition, unlike most prior research, which uses generic products in fMRI studies, this study is utilizing high technology product to investigate the brand switching behavior.

Mapping of cognitive functions in chronic intractable epilepsy: Role of fMRI

Background:Functional magnetic resonance imaging (fMRI), a non-invasive technique with high spatial resolution and blood oxygen level dependent (BOLD) contrast, has been applied to localize and map cognitive functions in the clinical condition of chronic intractable epilepsy.Purpose:fMRI was used to map the language and memory network in patients of chronic intractable epilepsy pre- and post-surgery.Materials and Methods:After obtaining approval from the institutional ethics committee, six patients with intractable epilepsy with an equal number of age-matched controls were recruited in the study. A 1.5 T MR scanner with 12-channel head coil, integrated with audio-visual fMRI accessories was used. Echo planar imaging sequence was used for BOLD studies. There were two sessions in TLE (pre- and post-surgery).Results:In TLE patients, BOLD activation increased post-surgery in comparison of pre-surgery in inferior frontal gyrus (IFG), middle frontal gyrus (MFG), and superior temporal gyrus (STG), during semantic lexical, judgment, comprehension, and semantic memory tasks.Conclusion:Functional MRI is useful to study the basic concepts related to language and memory lateralization in TLE and guide surgeons for preservation of important brain areas during ATLR. This will help in understanding future directions for the diagnosis and treatment of such disease.

Natural history of CMT disease: A 18 months follow-up study through gait analysis

Abstracts / Gait & Posture 37 (2013) S1–S31 S11Fig. 1. Materialsandmethods:FunctionalMagneticResonanceImag-ing (fMRI) task, consisting in observation of spatial targettrajectories and their recall from memory, was administered to 22healthysubjects.Theobservedmovementsconsistedinupperlimbreaching tasks (Fig. 1A) and computer generated dot movements(Fig. 1B) visualized in subsequent random sequences. The subjecthad to decide if trajectories were congruent with the given target.Control on responses was tested introducing trials with congruentand incongruent targets.Results: The observation of upper limb reaching and dot move-ments induced similar patterns of activations according to acaudo-rostral pathway (including specific areas of the occipital,temporal,parietal,andfrontallobes),seeorangeoverlappingareasin Fig. 2. Similarly, evidence of visual processing of movementswerefoundforthesubsequentretrievaloftheobservedmovement.Furthermore, activations of frontal cortical areas were evidentwhenthesubjectwasdecidingwhetherthetargettrajectorieswerecongruent or not.Discussion: We identified the neural pathways associatedwith visual processing of movement stimuli used in upper limbrobot-mediated training. In both study conditions, activationswere elicited in cerebral areas involved in visual perception, sen-sory integration, recognition of movement, re-mapping on thesomatosensory and motor cortex, memory recall and responsecontrol. Furthermore, we documented the brain’s ability to assim-ilate abstract object movements trajectories with human motorgestures. This results suggest the appropriateness of the visualfeedback provided during robotic motor training. The results ofour study highlight the role of fMRI in improving the understand-ing of visual motor analysis and decision processing during brainreorganisation after training.

Functional Magnetic Resonance in the Evaluation of Oesophageal Motility Disorders

Functional magnetic resonance imaging (fMRI) has been recently proposed for the evaluation of the esophagus. Our aim is to assess the role of fMRI as a technique to assess morphological and functional parameters of the esophagus in patients with esophageal motor disorders and in healthy controls. Subsequently, we assessed the diagnostic efficiency of fMRI in comparison to videofluoroscopic and manometric findings in the investigation of patients with esophageal motor disorders. Considering that fMRI was shown to offer valuable information on bolus transit and on the caliber of the esophagus, variations of these two parameters in the different types of esophageal motor alterations have been assessed. fMRI, compared to manometry and videofluoroscopy, showed that a deranged or absent peristalsis is significantly associated with slower transit time and with increased esophageal diameter. Although further studies are needed, fMRI represents a promising noninvasive technique for the integrated functional and morphological evaluation of esophageal motility disorders.

A functional magnetic resonance proof of concept pilot trial of cognitive rehabilitation in multiple sclerosis

Background: Cognitive impairment is frequent in multiple sclerosis (MS) and lacks effective treatment. Cognitive rehabilitation is widely applied in neurorehabilitation settings. Functional magnetic resonance imaging (fMRI) may help in investigating changes in brain activity and provide a tool to assess the efficacy of rehabilitation. Aim: To investigate the effect on brain activity as measured by fMRI of a cognitive rehabilitation programme in patients with MS and cognitive impairment. Method: Fifteen patients with MS and cognitive impairment and five healthy subjects were recruited. Neuropsychological assessments were performed in patients with MS at study entry and after rehabilitation to assess cognitive changes. fMRI scans were performed at week −5 (baseline), week 0 (immediately before rehabilitation) and week 5 (immediately after rehabilitation). The fMRI paradigm was the Paced Auditory Serial Addition Test (PASAT). The cognitive rehabilitation programme was composed of 15 computer-aided drill and practice sessions and five non-computer-aided cognitive stimulation group sessions (over 5 weeks). Strict guidelines ensured comparability of all rehabilitation interventions. Results: Patients had increased brain fMRI activity after rehabilitation in several cerebellar areas when compared with healthy subjects. After rehabilitation, patients had significantly improved their performance on the backward version of the Digit Span Test (p = 0.007) and on a composite score of neuropsychological outcomes (p = 0.009). Conclusion: The results of the present study indicate that this cognitive rehabilitation programme increases brain activity in the cerebellum of cognitively impaired patients with MS. The role of fMRI in the assessment of neurorehabilitation schemes warrants further investigation.

Disconnected brains: What is the role of fMRI in connectivity research?

In this paper we consider how functional Magnetic Resonance Imaging (fMRI) has been used to study cortical connectivity in autism and autistic spectrum disorders (ASD). We discuss those studies that have contributed to the evidence supporting a model of disordered cortical connectivity in autism and (ASD), with a focusing emphasis on the application to research into the underconnectivity model. We note that the analytical techniques employed are limited and do not allow interpretation in terms of effective, or directional connectivity, nor do they provide information about the temporal or spectral characteristics of the functional networks being studied. We highlight how currently the features of neural generators that are being assessed by functional connectivity in fMRI are unclear. In addition, we note the importance in clinical studies of considering the consequences of task choice for the nature of the imaging data that can be collected and also of individual differences in participant state and trait characteristics for the accurate interpretation of imaging data. We discuss how alternative techniques such as EEG/MEG may address the limitations of fMRI in assessing brain connectivity, and additionally consider the potential of multimodal approaches. We conclude that fMRI has made significant contributions towards our understanding of the brain in terms of neural systems but that the conclusions drawn from its application in the sphere of autism research need to be approached with caution. It is important in research of this kind that we are aware of the need to examine the methodological and analytical techniques closely when applying findings in clinical populations, not only when they are used to support the development of theoretical models but also to inform diagnostic or treatment decisions.

Beyond BOLD: Expanding the role of fMRI in low vision rehabilitation

Beyond BOLD: Expanding the role of fMRI in low vision rehabilitation

Applications of functional magnetic resonance imaging in psychiatry

While the use of MRI techniques has become a cornerstone of the neurology clinic, the application of such methods in psychiatry was rather limited until the advent of functional magnetic resonance imaging (fMRI). Over the past decade fMRI has superseded radionuclide-imaging techniques and blossomed into a widely used psychiatric research tool. This review focuses on the neurobiological findings from fMRI research in three less well-documented psychiatric disorders: attention deficit hyperactivity disorder (ADHD), depression, and obsessive-compulsive disorder (OCD). Although there was some disparity in early findings, greater standardization of image acquisition, analysis, and paradigms, and improved clinical classification are leading to a greater convergence of observations from different laboratories. fMRI is also beginning to realize its potential as an important mediator between genes and phenotypes, and may thus contribute to a better understanding of the pathophysiology of major neuropsychiatric diseases. The role of fMRI in the objective assessment of therapeutic intervention and early prediction of response to treatment is also discussed.

Role of fMRI in the decision‐making process: Epilepsy surgery for children

Functional MRI (fMRI) is increasingly being used to evaluate children and adolescents who are candidates for surgical treatment of intractable epilepsy. It has the advantage of being noninvasive and well tolerated by young people. By identifying important functional regions within the brain, including unpredictable patterns of functional reorganization, it can aid in surgical decision-making. Here we illustrate this using a number of case studies from the pediatric epilepsy surgery program at our institution. We describe how fMRI, used in conjunction with conventional investigative methods such as neuropsychological assessment, MRI, and electrophysiology, can 1) help to improve functional outcome by enabling resective surgery that spares functional cortex, 2) guide surgical intervention by revealing when reorganization of function has occurred, and 3) show when abnormal cortex is also functionally active, and hence that surgery may not be the best option. Altogether, these roles have reduced the need for invasive procedures that can be both risky and distressing for young people with epilepsy. In our experience, fMRI has significantly contributed to the decision-making process, and improved the counseling and management of young people with intractable epilepsy.

The role of fMRI in drug discovery

Pharmacological functional (phMRI) studies are making a significant contribution to our understanding of drug-effects on brain systems. Pharmacological fMRI has an additional contribution to make in the translation of disease models and candidate compounds from preclinical to clinical investigation and in the early clinical stages of drug development. Here it can demonstrate a proof-of-concept of drug action in a small human cohort and thus contribute substantially to decision-making in drug development. We review the methods underlying pharmacological fMRI studies and the links that can be made between animal and human investigations. We discuss the potential fMRI markers of drug effect, experimental designs and caveats in interpreting hemodynamic fMRI data as reflective of changes in neuronal activity. Although there are no current published examples of fMRI applied to novel compounds, we illustrate the potential of fMRI across a range of applications and with specific reference to processing of pain in the human brain and pharmacological analgesia. Pharmacological fMRI is developing to meet the neuroscientific challenges. Electrophysiological methods can be used to corroborate the drug effects measured hemodynamically with fMRI. In future, pharmacological fMRI is likely to extend to examinations of the spinal cord and into pharmacogenetics to relate genetic polymorphisms to differential responses of the brain to drugs.

The Role of fMRI in Aphasiology: Interface Between Technology, Theory, and Clinical Care

The Role of fMRI in Aphasiology: Interface Between Technology, Theory, and Clinical Care

The Role of Functional MRI in the Presurgical Investigation of Temporal Lobe Epilepsy Patients: A Clinical Perspective and Review

Speculation regarding the role that fMRI might play in the presurgical assessment of temporal lobe epilepsy patients began almost as soon as the technology was introduced. Much of this speculation centred on hopes that fMRI might eventually supersede the invasive intracarotid amobarbital procedure (IAP). This review examines the progress that has been made to date towards this aim. A decade after its inception, fMRI paradigms that reliably lateralize language dominance have been established. However, fMRI has yet to achieve its full potential in the mapping of clinically relevant language skills in presurgical epilepsy patients. The role of fMRI in the assessment of postoperative amnesic risk is more complex. The results from recent fMRI memory studies in people with epilepsy have been encouraging. However, as yet, fMRI techniques cannot be used alone to confidently assess the risk of a postsurgical amnesic syndrome. It seems probable that these techniques will continue to be combined with traditional neuropsychological assessment and information from structural MRI studies and the other presurgical investigations to assess postoperative amnesic risk.