scholarly journals Jargonaphasia as a disconnection syndrome: A study combining white matter electrical stimulation and disconnectome mapping

2021 ◽  
Author(s):  
Davide Giampiccolo ◽  
Sylvie Moritz-Gasser ◽  
Sam Ng ◽  
Anne-Laure Lemaître ◽  
Hugues Duffau
Keyword(s):  
Electrical Stimulation ◽  
White Matter ◽  
Disconnection Syndrome

scholarly journals The Role of White Matter Disconnection in the Symptoms Relating to the Anarchic Hand Syndrome: A Single Case Study

2021 ◽  
Vol 11 (5) ◽  
pp. 632
Author(s):  
Valentina Pacella ◽  
Giuseppe Kenneth Ricciardi ◽  
Silvia Bonadiman ◽  
Elisabetta Verzini ◽  
Federica Faraoni ◽  
...  
Keyword(s):  
White Matter ◽  
Single Case ◽  
Brain Lesion ◽  
Structural Connectivity ◽  
Disconnection Syndrome ◽  
Neuroimaging Data ◽  
Neuropsychological Investigation ◽  
Anterior Posterior

The anarchic hand syndrome refers to an inability to control the movements of one’s own hand, which acts as if it has a will of its own. The symptoms may differ depending on whether the brain lesion is anterior, posterior, callosal or subcortical, but the relative classifications are not conclusive. This study investigates the role of white matter disconnections in a patient whose symptoms are inconsistent with the mapping of the lesion site. A repeated neuropsychological investigation was associated with a review of the literature on the topic to identify the frequency of various different symptoms relating to this syndrome. Furthermore, an analysis of the neuroimaging regarding structural connectivity allowed us to investigate the grey matter lesions and white matter disconnections. The results indicated that some of the patient’s symptoms were associated with structures that, although not directly damaged, were dysfunctional due to a disconnection in their networks. This suggests that the anarchic hand may be considered as a disconnection syndrome involving the integration of multiple antero-posterior, insular and interhemispheric networks. In order to comprehend this rare syndrome better, the clinical and neuroimaging data need to be integrated with the clinical reports available in the literature on this topic.

scholarly journals The Role of White Matter Disconnection in the Symptoms Relating to the Anarchic Hand Syndrome: A Single Case Study

2021 ◽  
Author(s):  
Valentina Pacella ◽  
Giuseppe Kenneth Ricciardi ◽  
Silvia Bonadiman ◽  
Elisabetta Verzini ◽  
Federica Faraoni ◽  
...  
Keyword(s):  
White Matter ◽  
Single Case ◽  
Brain Lesion ◽  
Structural Connectivity ◽  
Disconnection Syndrome ◽  
Neuroimaging Data ◽  
Neuropsychological Investigation ◽  
Anterior Posterior

The anarchic hand syndrome refers to an inability to control the movements of one’s own hand which acts as if it had a will of its own. The symptoms may differ depending on whether the brain lesion is anterior, posterior, callosal or subcortical, but the relative classifications are not conclusive. This study investigates the role of white matter disconnections in a patient whose symptoms are inconsistent with the mapping of the lesion site. A repeated neuropsychological investigation was associated with a review of the literature on the topic to identify the frequency of various different symptoms relating to this syndrome. Furthermore, an analysis of the neuroimaging regarding structural connectivity allowed us to investigate the grey matter lesions and white matter disconnections. The results indicated that some of the patient’s symptoms were associated with structures that, although not directly damaged, were dysfunctional due to a disconnection in their networks. This suggests that the anarchic hand may be considered as a disconnection syndrome involving the integration of multiple antero-posterior, insular and interhemispheric networks. In order to comprehend this rare syndrome better, the clinical and neuroimaging data need to be integrated with the clinical reports available in the literature on the topic.

scholarly journals Intraoperative subcortical mapping of a language-associated deep frontal tract connecting the superior frontal gyrus to Broca's area in the dominant hemisphere of patients with glioma

2015 ◽  
Vol 122 (6) ◽  
pp. 1390-1396 ◽  
Author(s):  
Masazumi Fujii ◽  
Satoshi Maesawa ◽  
Kazuya Motomura ◽  
Miyako Futamura ◽  
Yuichiro Hayashi ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
White Matter ◽  
Frontal Lobe ◽  
Navigation System ◽  
Broca’S Area ◽  
Language Function ◽  
Broca's Area ◽  
Mr Images ◽  
Language Functions ◽  
Subcortical Mapping

OBJECT The deep frontal pathway connecting the superior frontal gyrus to Broca's area, recently named the frontal aslant tract (FAT), is assumed to be associated with language functions, especially speech initiation and spontaneity. Injury to the deep frontal lobe is known to cause aphasia that mimics the aphasia caused by damage to the supplementary motor area. Although fiber dissection and tractography have revealed the existence of the tract, little is known about its function. The aim of this study was to determine the function of the FAT via electrical stimulation in patients with glioma who underwent awake surgery. METHODS The authors analyzed the data from subcortical mapping with electrical stimulation in 5 consecutive cases (3 males and 2 females, age range 40–54 years) with gliomas in the left frontal lobe. Diffusion tensor imaging (DTI) and tractography of the FAT were performed in all cases. A navigation system and intraoperative MRI were used in all cases. During the awake phase of the surgery, cortical mapping was performed to find the precentral gyrus and Broca's area, followed by tumor resection. After the cortical layer was removed, subcortical mapping was performed to assess language-associated fibers in the white matter. RESULTS In all 5 cases, positive responses were obtained at the stimulation sites in the subcortical area adjacent to the FAT, which was visualized by the navigation system. Speech arrest was observed in 4 cases, and remarkably slow speech and conversation was observed in 1 case. The location of these sites was also determined on intraoperative MR images and estimated on preoperative MR images with DTI tractography, confirming the spatial relationships among the stimulation sites and white matter tracts. Tumor removal was successfully performed without damage to this tract, and language function did not deteriorate in any of the cases postoperatively. CONCLUSIONS The authors identified the left FAT and confirmed that it was associated with language functions. This tract should be recognized by clinicians to preserve language function during brain tumor surgery, especially for tumors located in the deep frontal lobe on the language-dominant side.

scholarly journals White Matter Network Architecture Guides Direct Electrical Stimulation Through Optimal State Transitions

2018 ◽  
Author(s):  
Jennifer Stiso ◽  
Ankit N. Khambhati ◽  
Tommaso Menara ◽  
Ari E. Kahn ◽  
Joel M. Stein ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
White Matter ◽  
Formal Model ◽  
Empirical Support ◽  
Network Control ◽  
Energy Requirements ◽  
State Transitions ◽  
Direct Electrical Stimulation ◽  
White Matter Tracts ◽  
The Brain

AbstractElectrical brain stimulation is currently being investigated as a potential therapy for neurological disease. However, opportunities to optimize and personalize such therapies are challenged by the fact that the beneficial impact (and potential side effects) of focal stimulation on both neighboring and distant regions is not well understood. Here, we use network control theory to build a formal model of brain network function that makes explicit predictions about how stimulation spreads through the brain’s white matter network and influences large-scale dynamics. We test these predictions using combined electrocorticography (ECoG) and diffusion weighted imaging (DWI) data from patients with medically refractory epilepsy undergoing evaluation for resective surgery, and who volunteered to participate in an extensive stimulation regimen. We posit a specific model-based manner in which white matter tracts constrain stimulation, defining its capacity to drive the brain to new states, including states associated with successful memory encoding. In a first validation of our model, we find that the true pattern of white matter tracts can be used to more accurately predict the state transitions induced by direct electrical stimulation than the artificial patterns of a topological or spatial network null model. We then use a targeted optimal control framework to solve for the optimal energy required to drive the brain to a given state. We show that, intuitively, our model predicts larger energy requirements when starting from states that are farther away from a target memory state. We then suggest testable hypotheses about which structural properties will lead to efficient stimulation for improving memory based on energy requirements. We show that the strength and homogeneity of edges between controlled and uncontrolled nodes, as well as the persistent modal controllability of the stimulated region, predict energy requirements. Our work demonstrates that individual white matter architecture plays a vital role in guiding the dynamics of direct electrical stimulation, more generally offering empirical support for the utility of network control theoretic models of brain response to stimulation.

scholarly journals Transcriptome of rat subcortical white matter and spinal cord after spinal injury and cortical stimulation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Bethany R. Kondiles ◽  
Haichao Wei ◽  
Lesley S. Chaboub ◽  
Philip J. Horner ◽  
Jia Qian Wu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Electrical Stimulation ◽  
White Matter ◽  
Neural Plasticity ◽  
Spinal Injury ◽  
Subcortical White Matter ◽  
Motor Dysfunction ◽  
Data Set ◽  
Cord Injury

AbstractSpinal cord injury disrupts ascending and descending neural signals causing sensory and motor dysfunction. Neuromodulation with electrical stimulation is used in both clinical and research settings to induce neural plasticity and improve functional recovery following spinal trauma. However, the mechanisms by which electrical stimulation affects recovery remain unclear. In this study we examined the effects of cortical electrical stimulation following injury on transcription at several levels of the central nervous system. We performed a unilateral, incomplete cervical spinal contusion injury in rats and delivered stimulation for one week to the contralesional motor cortex to activate the corticospinal tract and other pathways. RNA was purified from bilateral subcortical white matter and 3 levels of the spinal cord. Here we provide the complete data set in the hope that it will be useful for researchers studying electrical stimulation as a therapy to improve recovery from the deficits associated with spinal cord injury.

scholarly journals Two Different Subcortical Networks of Language System: Morphogram and Phonogram, Through the Analysis of Unique Japanese Characters

2021 ◽  
Author(s):  
Sho Tamai ◽  
Masashi Kinoshita ◽  
Riho Nakajima ◽  
Hirokazu Okita ◽  
Mitsutoshi Nakada
Keyword(s):  
Electrical Stimulation ◽  
White Matter ◽  
Surgical Resection ◽  
Parietal Lobe ◽  
The Other ◽  
Reading Process ◽  
Direct Electrical Stimulation ◽  
Cerebral Glioma ◽  
Language Mapping ◽  
Language Assessments

Abstract Language systems worldwide are based on morphograms or phonograms, and Japanese is a unique language that uses a complicated combination of kanji (morphogram) and kana (phonogram) characters. The white matter networks associated with reading have been investigated previously but remain unclear. In this study, we performed intraoperative language mapping under local anesthesia and postoperative language assessments of 65 consecutive patients who underwent surgical resection for cerebral glioma within the dominant temporal or parietal lobe. The cases showing intraoperative dyslexia elicited by direct electrical stimulation (DES) or postoperative kanji and/or kana dyslexia were extracted. Five patients showed transient kanji or kana dyslexia intraoperatively, and 8 patients showed kanji or kana dyslexia postoperatively. During intraoperative mapping, kanji or kana dyslexia were indeed reproduced by DES. We investigated the maximal overlapping lesions of the resection cavity that were associated with kanji or kana dyslexia, and then determined the subcortical elicited points that evoked kanji or kana dyslexia. These areas were localized near three white matter bundles: the arcuate fascicle, posterior superior longitudinal fascicle, and inferior longitudinal fascicle (ILF). The intraoperative DES distributions for kanji dyslexia were especially associated with the anterior-inferior side of the ILF. On the other hand, the DES point associated with kana dyslexia was localized on the posterior-superior side of the complex of these three tracts. These results suggested the presence of specific non-interfering networks that subserved the reading process for morphograms and phonograms.

scholarly journals Contribution of diffusion, perfusion and functional MRI to the disconnection hypothesis in subcortical vascular cognitive impairment

2018 ◽  
Vol 3 (3) ◽  
pp. 131-139 ◽  
Author(s):  
Qing Ye ◽  
Feng Bai
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Functional Mri ◽  
Diffusion Tensor ◽  
Small Vessel Disease ◽  
Vascular Cognitive Impairment ◽  
Brain Abnormalities ◽  
Disconnection Syndrome ◽  
Subcortical Regions ◽  
Cortical Regions

Vascular cognitive impairment (VCI) describes all forms of cognitive impairment caused by any type of cerebrovascular disease. Early identification of VCI is quite difficult due to the lack of both sensitive and specific biomarkers. Extensive damage to the white matter tracts, which connect the cortical and subcortical regions, has been shown in subcortical VCI (SVCI), the most common subtype of VCI that is caused by small vessel disease. Two specific MRI sequences, including diffusion tensor imaging (DTI) and functional MRI (fMRI), have emerged as useful tools for identifying subtle white matter changes and the intrinsic connectivity between distinct cortical regions. This review describes the advantages of these two modalities in SVCI research and the current DTI and fMRI findings on SVCI. Using DTI technique, a variety of studies found that white matter microstructural damages in the anterior and superior areas are more specific to SVCI. Similarly, functional brain abnormalities detected by fMRI have also been mainly shown in anterior brain areas in SVCI. The characteristic distribution of brain abnormalities in SVCI interrupts the prefrontal-subcortical loop that results in cognitive impairments in particular domains, which further confirms the ‘disconnection syndrome’ hypothesis. In addition, another MRI technique, arterial spin labelling (ASL), has been used to describe the disconnection patterns in a variety of conditions by measuring cerebral blood flow. The role of the ASL technique in SVCI research is also assessed. Finally, the review proposes the application of multimodality fusion in the investigation of SVCI pathogenesis.

scholarly journals Focal Increases of White Matter Glucose Utilization Produced by Electrical Stimulation of Rat Motor Cortex

1983 ◽  
Vol 3 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Frank R. Sharp ◽  
Sherzad Bzorgchami ◽  
Thomas Kilduff
Keyword(s):  
Electrical Stimulation ◽  
White Matter ◽  
Motor Cortex ◽  
Glucose Utilization ◽  
Pyramidal Tract ◽  
Internal Capsule ◽  
Local Cerebral Glucose Utilization ◽  
The Right ◽  
Deoxyglucose Method ◽  
Stimulation Of

The right motor cortex was electrically stimulated in adult, awake rats for 45 min. Local cerebral glucose utilization (LCGU) was measured in white matter pathways with the (14C)-2-deoxyglucose method. Stimulation increased LCGU in focal regions of the right internal capsule to 51.3 μmol/100 g/min, compared to 39.8 on the control left side. Stimulation also increased LCGU in the right, medial pontine pyramidal tract to 36.2 μmol/100 g/min, compared with 27.3 on the control left side. The data demonstrate that electrical stimulation of motor cortex neurons increases LCGU 30 to 40% in the efferent myelinated axons of those neurons.

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