Brain Mapping Techniques Research Articles

The Intersection of Neuroscience and Criminology: Role of Brain Mapping in Addressing Criminal Behavior by Nepal Police

Neuroscience is being integrated into criminal investigations, offering new opportunities for understanding, predicting, and potentially preventing criminal behavior. In Nepal, brain-mapping techniques like P300 wave tests and Brain Electrical Oscillation Signature profiling were used in a murder investigation in 2024. However, ethical concerns include privacy concerns, false positives, and the potential for false positives. Consent regarding neurobiological evidence in criminal cases is crucial, as intrusive procedures may require individuals to be informed. The legal implications of using neurobiological evidence could be severe if it serves to wrongfully accuse or convict an individual. Therefore, the use of neuroscience in criminology must be carefully balanced to ensure ethical considerations. This viewpoint interprets the potential of neuroscience in criminal investigations, addressing ethical, privacy, consent, and legal issues within the Nepal Police and criminal justice system.

Functional mapping of movement and speech using task-based electrophysiological changes in stereoelectroencephalography.

Stereoelectroencephalography (SEEG) has become the predominant method for intracranial seizure localization. When imaging, semiology, and scalp EEG findings are not in full agreement or definitively localizing, implanted SEEG recordings are used to test candidate seizure onset zones (SOZs). Discovered SOZs may then be targeted for resection, laser ablation, or neurostimulation. If an SOZ is eloquent, resection and ablation are both contraindicated, so identifying functional representation is crucial for therapeutic decision-making. The authors present a novel functional brain mapping technique that utilizes task-based electrophysiological changes in SEEG during behavioral tasks and test this in pediatric and adult patients. SEEG was recorded in 20 patients with epilepsy who ranged in age from 6 to 39 years (12 female, 18 of 20 patients < 21 years of age) and underwent implanted monitoring to identify seizure onset. Each performed 1) visually cued simple repetitive movements of the hand, foot, or tongue while electromyography was recorded; and 2) simple picture-naming or verb-generation speech tasks while audio was recorded. Broadband changes in the power spectrum of the SEEG recording were compared between behavior and rest. Electrophysiological functional mapping of movement and/or speech areas was completed in all 20 patients. Eloquent representation was identified in both cortex and white matter and generally corresponded to classically described functional anatomical organization as well as other clinical mapping results. Robust maps of brain activity were identified in healthy brain, regions of developmental or acquired structural abnormality, and SOZs. Task-based electrophysiological mapping using broadband changes in the SEEG signal reliably identifies movement and speech representation in pediatric and adult epilepsy patients.

Utilizing connectome fingerprinting functional MRI models for motor activity prediction in presurgical planning: A feasibility study.

Presurgical planning prior to brain tumor resection is critical for the preservation of neurologic function post-operatively. Neurosurgeons increasingly use advanced brain mapping techniques pre- and intra-operatively to delineate brain regions which are "eloquent" and should be spared during resection. Functional MRI (fMRI) has emerged as a commonly used non-invasive modality for individual patient mapping of critical cortical regions such as motor, language, and visual cortices. To map motor function, patients are scanned using fMRI while they perform various motor tasks to identify brain networks critical for motor performance, but it may be difficult for some patients to perform tasks in the scanner due to pre-existing deficits. Connectome fingerprinting (CF) is a machine-learning approach that learns associations between resting-state functional networks of a brain region and the activations in the region for specific tasks; once a CF model is constructed, individualized predictions of task activation can be generated from resting-state data. Here we utilized CF to train models on high-quality data from 208 subjects in the Human Connectome Project (HCP) and used this to predict task activations in our cohort of healthy control subjects (n = 15) and presurgical patients (n = 16) using resting-state fMRI (rs-fMRI) data. The prediction quality was validated with task fMRI data in the healthy controls and patients. We found that the task predictions for motor areas are on par with actual task activations in most healthy subjects (model accuracy around 90%-100% of task stability) and some patients suggesting the CF models can be reliably substituted where task data is either not possible to collect or hard for subjects to perform. We were also able to make robust predictions in cases in which there were no task-related activations elicited. The findings demonstrate the utility of the CF approach for predicting activations in out-of-sample subjects, across sites and scanners, and in patient populations. This work supports the feasibility of the application of CF models to presurgical planning, while also revealing challenges to be addressed in future developments. PRACTITIONER POINTS: Precision motor network prediction using connectome fingerprinting. Carefully trained models' performance limited by stability of task-fMRI data. Successful cross-scanner predictions and motor network mapping in patients with tumor.

A state-of-the-art review of functional magnetic resonance imaging technique integrated with advanced statistical modeling and machine learning for primary headache diagnosis.

Primary headache is a very common and burdensome functional headache worldwide, which can be classified as migraine, tension-type headache (TTH), trigeminal autonomic cephalalgia (TAC), and other primary headaches. Managing and treating these different categories require distinct approaches, and accurate diagnosis is crucial. Functional magnetic resonance imaging (fMRI) has become a research hotspot to explore primary headache. By examining the interrelationships between activated brain regions and improving temporal and spatial resolution, fMRI can distinguish between primary headaches and their subtypes. Currently the most commonly used is the cortical brain mapping technique, which is based on blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI). This review sheds light on the state-of-the-art advancements in data analysis based on fMRI technology for primary headaches along with their subtypes. It encompasses not only the conventional analysis methodologies employed to unravel pathophysiological mechanisms, but also deep-learning approaches that integrate these techniques with advanced statistical modeling and machine learning. The aim is to highlight cutting-edge fMRI technologies and provide new insights into the diagnosis of primary headaches.

Role of Neural Plasticity of Motor Cortex in Gliomas Evaluated by Brain Imaging and Mapping Techniques in Pre- and Postoperative Period: A Systematic Review.

Resection of infiltrative neuroepithelial primary brain tumors, such as low-grade gliomas (LGGs) remains a neurosurgical challenge. Usual lack of clinical deficit despite LGGs growing in eloquent brain areas may be explained by reshaping and reorganization of functional networks. The development of modern diagnostic imaging techniques could disclose better understanding of the rearrangement of the brain cortex; however, mechanisms underlying such compensation and how it occurs in the motor cortex remain unclear. This systematic review aims to analyze the neuroplasticity of motor cortex in patients with LGGs, as determined by neuroimaging and functional techniques. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, medical subject headings (MeSH) and the following terms related to neuroimaging, LGGs and neuroplasticity were used with the Boolean operators AND and OR to synonymous terms in the PubMed database. Among the 118 results, 19 studies were included in the systematic review. Motor function in patients with LGG was characterized by a compensation in the contralateral and supplementary motor areas and premotor functional networks. Furthermore, ipsilateral activation in these types of gliomas was rarely described. Moreover, some studies did not reveal statistical significance in association between functional reorganization and the postoperative period, which can be explained by the low number of patients. Our findings suggest a high pattern of reorganization per different eloquent motor areas and gliomas diagnosis. Understanding this process is useful to guide safe surgical resection and to develop protocols that assess the plasticity, even though functional network rearrangement needs to be better characterized by more studies.

Breakthroughs in Alzheimer's Research: A Path to a More Promising Future?

Alzheimer's disease (AD) is a widespread neurodegenerative disorder with a significant global impact, affecting approximately 50 million individuals, and projections estimate that up to 152 million people will be affected by 2050. AD is characterized by beta-amyloid plaques and tau tangles in the brain, leading to cognitive decline. Recent research on AD has made significant strides, including the development of an "amyloid clock" biomarker that tracks AD progression through positron emission tomography (PET) scans. Surf4 and other genes have been discovered to play a role in regulating beta-amyloid toxicity, while inhibiting the enzyme hexokinase-2 has shown positive results in preclinical studies. New brain mapping techniques have identified early brain-based causes of cognitive changes in AD, and biomarkers such as neuronal pentraxin protein Nptx2 and astrocytic 7-subunit of the nicotinic acetylcholine receptors (7nAChRs) show potential for early detection. Other approaches, such as replenishing the enzyme Tip60, selectively degrading the modified protein p-p38 with PRZ-18002, and targeting the protein voltage-dependent anion channel-1 (VDAC1), have shown promise in enhancing cognitive function and preventing pathophysiological alterations linked to AD. Baseline blood samples and other biomarkers such as urine formic acid, p-tau 198, microRNAs, and glial fibrillary acidic protein (GFAP) have also been discovered for early detection and intervention of AD. Additionally, recent FDA approvals for medications such as aducanumab and lecanemab provide options for reducing AD symptoms and improving function, while clinical trials for dementia vaccines show promise for the nasal and beta-amyloid 40 vaccines as well as vaccinations targeting tau. These advancements in AD research, including biomarker discovery and the development of disease-modifying treatments, are crucial steps towards improving the lives of those affected by AD and finding a cure for this debilitating disease.

Resective epilepsy surgery in a limited-resource settings: A cohort from a multi-disciplinary epilepsy team in a developing country.

Multidisciplinary pre-surgical evaluation is vital for epilepsy surgery decision and outcomes. Resective epilepsy surgery with assisted monitoring is currently a standard treatment for focal drug resistant epilepsy (DRE). In resource-limited countries, lack of epilepsy surgery center is a huge challenge. We presented and illustrated how to create a multidisciplinary protocol with resource-limited settings in a developing country and epilepsy surgery outcome using brain mapping and monitoring techniques for ensuring satisfactory resection. We created multicentric incomplete but complementary units covering all epilepsy-related sub-specialties and covering a wide geographical area in our country. Then, we conducted a prospective and multicentric study with low resource settings on patients with focal DRE, who underwent resective epilepsy surgery and were followed up for at least 12 months and were evaluated for postoperative seizure outcome and complications if present. Preoperative comprehensive clinical, neurophysiological, neuropsychological, and radiological evaluations were performed by multidisciplinary epilepsy team. Intraoperative brain mapping including awake craniotomy and direct stimulation techniques, neurophysiological monitoring, and electrocorticography was carried out during surgical resection. The study included 47 patients (18 females and 29 males) with mean age 20.4 ± 10.02 years. Twenty-two (46.8%) patients were temporal epilepsy while 25 (53.2%) were extra-temporal epilepsy. The epilepsy surgery outcome at the last follow up was Engel Class I (seizure free) in 35 (74.5%), Class II (almost seizure free) in 8 (17%), Class III (worthwhile improvement) in 3 (6.4%), and Class IV (no worthwhile improvement) in 1 patient (2.1%). With low resource settings and lack of single fully equipped epilepsy center, favorable outcomes after resective surgery in patients with focal DRE could be achieved using careful presurgical multidisciplinary selection, especially with using intraoperative brain mapping and electrocorticography techniques.

Large-scale brain networks and intra-axial tumor surgery: a narrative review of functional mapping techniques, critical needs, and scientific opportunities.

In recent years, a paradigm shift in neuroscience has been occurring from "localizationism," or the idea that the brain is organized into separately functioning modules, toward "connectomics," or the idea that interconnected nodes form networks as the underlying substrates of behavior and thought. Accordingly, our understanding of mechanisms of neurological function, dysfunction, and recovery has evolved to include connections, disconnections, and reconnections. Brain tumors provide a unique opportunity to probe large-scale neural networks with focal and sometimes reversible lesions, allowing neuroscientists the unique opportunity to directly test newly formed hypotheses about underlying brain structural-functional relationships and network properties. Moreover, if a more complete model of neurological dysfunction is to be defined as a "disconnectome," potential avenues for recovery might be mapped through a "reconnectome." Such insight may open the door to novel therapeutic approaches where previous attempts have failed. In this review, we briefly delve into the most clinically relevant neural networks and brain mapping techniques, and we examine how they are being applied to modern neurosurgical brain tumor practices. We then explore how brain tumors might teach us more about mechanisms of global brain dysfunction and recovery through pre- and postoperative longitudinal connectomic and behavioral analyses.

Brain Mapping in Neurosurgery

Background and Aim: Brain mapping is the study of the anatomy and function of the Central Nervous System (CNS). Brain mapping has many techniques and these techniques are permanently changing and updating. From the beginning, brain mapping was invasive and for brain mapping, electrical stimulation of the exposed brain was needed. However, nowadays brain mapping does not require electrical stimulation and often does not require any complex involvement of patients. To perform brain mapping, functional and structural neuroimaging has an essential role. The techniques for brain mapping include noninvasive techniques (structural and functional magnetic resonance imaging [fMRI], diffusion MRI [dMRI], magnetoencephalography [MEG], electroencephalography [EEG], positron emission tomography [PET], near-infrared spectroscopy [NIRS] and other non-invasive scanning techniques) and invasive techniques (direct cortical stimulation [DCS] and intracarotid amytal test [IAT] or wada test). Methods and Materials/Patients: This is a narrative study on brain mapping in neurosurgery. To provide up-to-date information on brain mapping in neurosurgery, we precisely reviewed brain mapping and neurosurgery articles. Using the keywords “brain mapping”, “neurosurgery”, “brain mapping techniques”, and “benefits of brain mapping”, all of the related articles were obtained from Google Scholar, PubMed, and Medline and were precisely studied. Results: To perform an effective and safe neurosurgical intervention, precise information about the structural and functional anatomy of the brain is obligatory. Based on the information on brain mapping, the selection of suitable patients for the operation, the plan of appropriate operative approach, and good surgical results can be acquired. To provide this information, we can use brain mapping techniques that were formerly applied in neuroscientific brain mapping efforts with noninvasive techniques, such as fMRI, MEG, dMRI, PET, etc and invasive techniques, such as DCS, IAT, etc. Conclusion: Functional brain mapping is a constantly evolving fact in neurosurgery. All stages in obtaining a functional image are complex and need knowledge of the basic physiologic and imaging features.

Examining the Low- Resolution Electromagnetic Tomography Technique for EEG Brain Mapping

NeuroIS presents a new opportunity for information systems research. Often used neuroscience techniques include brain mapping with the functional magnetic resonance imaging (fMRI) device or eventrelated potential time-domain studies with the electroencephalogram (EEG). The critics of EEG consider the poor spatial resolution as justification for EEG's inadequacy to brain mapping studies. However, the low-resolution electromagnetic tomography (LORETA) technique provides strong estimation parameters allowing EEG to perform brain mapping. This paper presents EEG (with lower number of channels) and LORETA techniques as an effective approach for exploratory investigation specially when researchers are constrained with lack of resources (specially at significantly lower costs). We demonstrate the effectiveness of EEG using sLORETA with respect to fMRI as proof-of-concept approach to study IS phenomenon. The results of such studies can serve as a preliminary step for further analysis with the use of more sophisticated neuroscience devices. This can enhance IS research by taking advantage of both high temporal and spatial resolution leading to reduced estimation errors of neural activity and stronger basis for correlating neural activity and specific tasks. We also present a set of guidelines for using the LORETA family of techniques in IS research.

Resection of tumors within and near to the primary Sensory-Motor cortex using Phase reversal Cortical mapping and bipolar stimulation

Objective Brain mapping techniques allow one to effectively approach tumors involving the primary sensory-motor cortex and nearby area (M1). Tumor resectability and maintenance of patient integrity depend on the ability to successfully identify motor tracts during resection by choosing the most appropriate neurophysiological paradigm for motor mapping. Mapping with a high frequency (HF) stimulation technique has emerged as the most efficient tool to identify motor tracts because of its versatility in different clinical settings. At present, few data are available on the use of HF for removal of tumors predominantly involving M1. Methods The authors have analysed a series of 6 patients with brain tumors within M1, by reviewing the use of HF as a guide. The neurophysiological protocols adopted during resections were described and correlated with patients’ clinical and tumor imaging features. Feasibility of mapping, extent of resection, and motor function assessment were used to evaluate the oncological and functional outcome to be correlated with the selected neurophysiological parameters used for guiding resection. The study aimed to define the most efficient protocol to guide resection for each clinical condition. gliomas

P07.08.B Surgical management of recurrent lower-grade gliomas: analysis of oncological and functional outcomes and associated factors

Abstract Background Presently, there are no clear evidence-based recommendations for the surgical management of progressive or recurrent lower-grade gliomas (LGGs). In our work, we evaluated the oncological (PFS, OS) and functional (neurological, neuropsychological, quality of life evaluation) outcomes of a series of LGGs treated in a 5-year period. The aim was to identify clinical, imaging, and molecular factors, associated with better outcomes, to be implemented in the treatment decision making process. Material and Methods In our retrospective analysis, 738 recurrent LGGs were included (follow-up 7.9 years; IQR:6-9); 550 were surgically treated, 495 with open resection (with brain mapping techniques), and 55 with tumor biopsy (with frameless stereotactic technique). Results Overall, 521 patients (70.6%) recurred. Of those treated with open resection 63.5% relapsed. Tumor progression was histologically confirmed in 72.5% of cases, no valuable tumor (effect of treatment) in 27.5% of cases (particularly in cases previously treated with RT and CHT), histo-molecular conversion (astrocytoma instead of oligodendroglioma diagnosis) in 7.5% of cases, malignant transformation in 38.7% of cases. Among the clinical (patient functional status, previous PFS, previous EOR, previous CHT and duration of CHT, previous RT), imaging (type of recurrence, i.e. typical versus atypical, speed of growth, contrast enhancement), and molecular (IDH, codeletion, ATRX, MGMT, tumor grade, CDNK status) factors analyzed, longest PFS of recurrent tumors was associated with patient functional status, previous PFS, previous EOR, speed of growth (&amp;gt;6 mm/year), atypical type of recurrence, tumor grade, presence of codeletion, and CDNK status. Best functional outcome associated with surgical resection, EOR, and tumor grade; worst functional outcome with RT and malignant transformation. Longest OS associated with previous EOR, surgical resection, tumor grade, presence of co-deletion. Malignant transformation was associated to previous EOR. Among patients submitted solely to tumor biopsy, changes in MGMT methylation status and in IDH status were observed in 65.3% and 5% of cases, respectively. Modification in IDH status was associated with atypical (distant) type of recurrence. New histo-molecular profile helped in the treatment decision making process. Conclusion Surgical resection of recurrent LGGs is associated with longer PFS and OS. Tumor biopsy should be considered, when surgery considered unfeasible, to tailor adjuvant treatment.

P07.10.B Preoperative brain mapping using transcranial magnetic stimulation applied to brain tumour resection surgery

Abstract Background Brain oncological surgery must pursue maximal tumour resection to achieve oncological benefits while preserving acceptable neurological function. Neuromonitoring techniques and brain mapping have been developed over the last decades to intraoperatively assess the exact location of neurological functions and secure their preservation. However, the fact that they cannot offer preoperative information and require in some cases the patient’s collaboration during displeasing awake surgeries raised the interest during last years on noninvasive techniques offering preoperative functional information. Navigated transcranial magnetic stimulation (nTMS) is a noninvasive technique able to create small magnetic fields and electrically stimulate brain cortex, emulating the effect obtained by cortical direct electrical stimulation (DES). It is a promising tool for performing pre-operative cortical brain mapping. Material and Methods We performed a unicenter prospective descriptive study including patients diagnosed with intra axial brain tumours neighboring cortical zones apparently implicated in motor and/or language functions who were planned for surgical resection. We performed preoperative nTMS (SofTaxic Neuro navigation system 3.0, EMS, Bologna) in all of them to define the location of these functions. Results Between November 2020 and December 2021 we included 18 patients (11 men, 7 women) with a mean age of 56 years (range 29-71). Location (8 temporal, 6 frontal, 3 parietal and 1 insular) and laterality (12 left, 6 right) of the brain tumours were registered. In all cases, cortical brain motor mapping with nTMS was performed with positive results, obtaining a mean anteroposterior diameter of the motor cortex of 22,75 mm. In 11 cases language mapping was also performed, detecting a total of 40 cortical language positive sites (31 frontal, 9 temporal) in those patient’s left hemispheres. No relevant side effects were noticed after nTMS performance. Definitive pathological results after surgery revealed high-grade glioma in 15 cases and low-grade glioma in 3. Conclusion nTMS is a recent noninvasive technique that allows the realization of preoperative cortical brain mapping. The information provided by this technique is of extreme value to better define surgical candidates and to plan brain tumour resection surgeries, according to functional cortical sites identified. The available literature describes its applications, mainly in localizing motor and language cortices, showing good concordance with intraoperative cortical DES, which is still the gold standard technique for brain mapping. Its integration in the pre-operative brain tumour assessment offers important advantages without adding relevant morbidity.

Encouraging Guidelines in Neuromusicological Research Regarding Classical Music’s Usage in Sonic Therapy - When Science Becomes Magic

"In systematic musicology as a branch of music psychology we found an intriguing orientation called cognitive neuroscience of music, or neuromusicology. It studies the function of the brain in music processing, the way music perception and production manifests in brain. Compared to other analytical models of music cognition, the mapping of the brain’s functioning serves to examine the outcome of music rather than its process, and as the music therapy methods discussed reflect, most approaches follow this ontological direction. As recent scientific researches shows, the brain mapping technique differentiates moment of listening, playing classical music or improvising. In the light of the research findings, our main focus was to get to know and understand how our musical brains functions during classical music audition so we could argue from a scientific approach not only the existing therapeutic methods used in music therapy, but the perception of classical music in the present. In the master class “Dialogue of the Arts”, we explore with our students in all grades the possible links between music and other artistic and scientific disciplines. One of the most exciting aspects of this is music and brain research, an incredibly fast-developing field whose results could reinforce the place and role of classical music in contemporary society, reinforcing existing broad-based promotion of classical music education (Kodály, El sistema etc.) Keywords: music cognition, neuromusicology, sonic therapy, classical music, models of therapy. "

Somatotopic Mapping of the Fingers in the Somatosensory Cortex Using Functional Magnetic Resonance Imaging: A Review of Literature.

Multiple studies have demonstrated finger somatotopy in humans and other primates using a variety of brain mapping techniques including functional magnetic resonance imaging (fMRI). Here, we review the literature to better understand the reliability of fMRI for mapping the somatosensory cortex. We have chosen to focus on the hand and fingers as these areas have the largest representation and have been the subject of the largest number of somatotopic mapping experiments. Regardless of the methods used, individual finger somatosensory maps were found to be organized across Brodmann areas (BAs) 3b, 1, and 2 in lateral-to-medial and inferior-to-superior fashion moving from the thumb to the pinky. However, some consistent discrepancies are found that depend principally on the method used to stimulate the hand and fingers. Therefore, we suggest that a comparative analysis of different types of stimulation be performed to address the differences described in this review.

Exploring the spatial resolution of TMS-EEG coupling on the sensorimotor region

The use of TMS-EEG coupling as a neuroimaging tool for the functional exploration of the human brain recently gained strong interest. If this tool directly inherits the fine temporal resolution from EEG, its spatial counterpart remains unknown. In this study, we explored the spatial resolution of TMS-EEG coupling by evaluating the minimal distance between two stimulated cortical sites that would significantly evoke different response dynamics. TMS evoked responses were mapped on the sensorimotor region in twenty participants. The stimulation grid was composed of nine targets separated between 10 and 15 mm on average. The dynamical signatures of TMS evoked activity were extracted and compared between sites using both local and remote linear regression scores and spatial generalized mixed models. We found a significant effect of the distance between stimulated sites on their dynamical signatures, neighboring sites showing differentiable response dynamics. Besides, common dynamical signatures were also found between sites up to 25-30 mm from each other. This overlap in dynamical properties decreased with distance and was stronger between sites within the same Brodmann area. Our results suggest that the spatial resolution of TMS-EEG coupling might be at least as high as 10 mm. Furthermore, our results reveal an anisotropic spatial resolution that was higher across than within the same Brodmann areas, in accordance with the TMS induced E-field modeling. Common cytoarchitectonic leading to shared dynamical properties within the same Brodmann area could also explain this anisotropy. Overall, these findings suggest that TMS-EEG benefits from the spatial resolution of TMS, which makes it an accurate technique for meso-scale brain mapping.

Neurological explanations of decision making in humans: A review

The present review paper focuses on neurological perspective of decision making which plays a major role in our daily life. Our success or failure heavily depends up on the decision we make. So, there is a strong connection between decision making and successful life. Decision making is one of the cognitive aspects that give high load to our brain. In processing decisions, neurons and blood oxygen levels play major role. The author tried to explore various brain regions that involved in decision making process in the light of previous research findings. The author has reviewed 50 research papers/dissertations/documents/ review reports and other sources. Most of the researches used brain mapping techniques to explain possible reasons behind decision making. The conceptual understandings of the review have been presented in the following sections. The author came across various types of decision making such as perceptual decision making, social decision making, economic decision making in relation to different brain regions like parietal cortex, medial premotor cortex. These aspects have been discussed and highlighted in the upcoming sections.

Anomalies in global network connectivity associated with early recovery from alcohol dependence: A network transcranial magnetic stimulation and electroencephalography study.

Although previous research in alcohol dependent populations identified alterations within local structures of the addiction ‘reward’ circuitry, there is limited research into global features of this network, especially in early recovery. Transcranial magnetic stimulation (TMS) is capable of non‐invasively perturbing the brain network while electroencephalography (EEG) measures the network response. The current study is the first to apply a TMS inhibitory paradigm while utilising network science (graph theory) to quantify network anomalies associated with alcohol dependence. Eleven individuals with alcohol‐dependence (ALD) in early recovery and 16 healthy controls (HC) were administered 75 single pulses and 75 paired‐pulses (inhibitory paradigm) to both the left and right prefrontal cortex (PFC). For each participant, Pearson cross‐correlation was applied to the EEG data and correlation matrices constructed. Global network measures (mean degree, clustering coefficient, local efficiency and global efficiency) were extracted for comparison between groups. Following administration of the inhibitory paired‐pulse TMS to the left PFC, the ALD group exhibited altered mean degree, clustering coefficient, local efficiency and global efficiency compared to HC. Decreases in local efficiency increased the prediction of being in the ALD group, while all network metrics (following paired‐pulse left TMS) were able to adequately discriminate between the groups. In the ALD group, reduced mean degree and global clustering was associated with increased severity of past alcohol use. Our study provides preliminary evidence of altered network topology in patients with alcohol dependence in early recovery. Network anomalies were predictive of high alcohol use and correlated with clinical features of alcohol dependence. Further research using this novel brain mapping technique may identify useful network biomarkers of alcohol dependence and recovery.

Functional Near-Infrared Spectroscopy as a Target Navigator for rTMS Modulation in Patients with Hemiplegia: A Randomized Control Study.

IntroductionAlthough repetitive transcranial magnetic stimulation (rTMS) is efficacious for motor neuromodulation in stroke survivors, high interindividual variability for responsiveness remains a concern. Target probing on the skull using a proper brain-mapping technique may help overcome this challenge. This study assessed the feasibility of functional near-infrared spectroscopy (fNIRS) as a target navigator in rTMS treatment for motor facilitation in patients with stroke.MethodsFifty-one patients with stroke were enrolled in this randomized controlled study. The patients were assigned to three groups: fNIRS-guided rTMS treatment (fNIRS group, n = 20), motor evoked potential (MEP)-guided rTMS treatment (MEP group, n = 16), and sham (n = 15) group. Motor assessments, including Fugl–Meyer Assessment (FMA), Wolf Motor Function Test (WMFT), and muscle strength, were conducted at baseline and after the 10-session rTMS treatment.ResultsThe fNIRS-guided hotspot (fNIRS-HS) was obtained for each patient, even those for whom the MEP-guided hotspot was undetectable. Both intervention groups exhibited significant improvements in muscle strength, FMA, and WMFT scores (P < 0.001) compared with the sham group. The fNIRS group achieved significantly greater improvement in elbow function (P = 0.001) than the MEP group.ConclusionfNIRS can be a reliable tool for hotspot navigation for motor neuromodulation in patients with stroke. With high sensitivity to cortical oxygenation changes, this navigation system achieved a superior outcome to the traditional MEP-based method in patients with stroke. fNIRS-based systems may also facilitate the integration of machine learning, thus enabling precision medicine for neuromodulation.Trial Registrationhttps://clinicaltrials.gov; Unique identifier: NCT02006615.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40120-021-00300-0.

Concurrent TMS/fMRI with high sensitivity and accelerated image acquisition

Abstract Functional magnetic resonance imaging (fMRI) has become the prime technique for non-invasive brain mapping as it yields high-resolution activation maps throughout the brain. Combined with TMS and applied simultaneously, concurrent TMS/fMRI offers the unique opportunity for directly assessing TMS-caused brain activity. Such, it is possible to study TMS effects across varying stimulation amplitude, protocol and targets. As changes in the BOLD fMRI signal are typically in range of only a few percent, high sensitivity acquisition is a prerequisite for successful TMS/fMRI. Standard concurrent TMS/fMRI setups are based on the use of single-channel, large-diameter birdcage coils that enable positioning of the TMS coil within the birdcage coil. In addition to their intrinsically low sensitivity, birdcage coils cannot be used with any of the various accelerated image acquisition methods used in MRI today, including parallel imaging (SENSE, GRAPPA) and multiband imaging (MB; simultaneous multi-slice, SMS). A different setup, based on thin, 7-channel receive arrays was recently proposed to overcome the shortcomings typical to birdcage coil setups [1,2]. Here we quantitatively assess the sensitivity of this new setup across a range of acquisition protocols. We also measure the effects of combining multiple receive-arrays for extended coverage. In particular, we show for the first time that it is possible to use three sets of 7-channel receive-arrays simultaneously to obtain unprecedentedly high sensitivity across the brain.