scholarly journals Changes in Cortical Activity in Stroke Survivors Undergoing Botulinum Neurotoxin Therapy for Treatment of Focal Spasticity

2021 ◽  
Vol 2 ◽  
Author(s):  
Kaleb Vinehout ◽  
Kelsey Tynes ◽  
Miguel R. Sotelo ◽  
Allison S. Hyngstrom ◽  
John R. McGuire ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Botulinum Neurotoxin ◽  
Botulinum Toxin A ◽  
Block Design ◽  
Premotor Cortex ◽  
Motor Impairment ◽  
Brain Activation ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen Level ◽  
Finger Flexion

Background: Botulinum NeuroToxin-A (BoNT-A) relieves muscle spasticity and increases range of motion necessary for stroke rehabilitation. Determining the effects of BoNT-A therapy on brain neuroplasticity could help physicians customize its use and predict its outcome.Objective: The purpose of this study was to investigate the effects of Botulinum Toxin-A therapy for treatment of focal spasticity on brain activation and functional connectivity.Design: We used functional Magnetic Resonance Imaging (fMRI) to track changes in blood oxygen-level dependent (BOLD) activation and functional connectivity associated with BoNT-A therapy in nine chronic stroke participants, and eight age-matched controls. Scans were acquired before BoNT-A injections (W0) and 6 weeks after the injections (W6). The task fMRI scan consisted of a block design of alternating mass finger flexion and extension. The voxel-level changes in BOLD activation, and pairwise changes in functional connectivity were analyzed for BoNT-A treatment (stroke W0 vs. W6).Results: BoNT-A injection therapy resulted in significant increases in brain activation in the contralesional premotor cortex, cingulate gyrus, thalamus, superior cerebellum, and in the ipsilesional sensory integration area. Lastly, cerebellar connectivity correlated with the Fugl-Meyer assessment of motor impairment before injection, while premotor connectivity correlated with the Fugl-Meyer score after injection.Conclusion: BoNT-A therapy for treatment of focal spasticity resulted in increased brain activation in areas associated with motor control, and cerebellar connectivity correlated with motor impairment before injection. These results suggest that neuroplastic effects might take place in response to improvements in focal spasticity.

Normalization of mediotemporal and prefrontal activity, and mediotemporal-striatal connectivity, may underlie antipsychotic effects of cannabidiol in psychosis

2020 ◽  
pp. 1-11 ◽  
Author(s):  
Aisling O'Neill ◽  
Robin Wilson ◽  
Grace Blest-Hopley ◽  
Luciano Annibale ◽  
Marco Colizzi ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Repeated Measures ◽  
Block Design ◽  
Study Drug ◽  
Learning Task ◽  
Blood Oxygen Level Dependent ◽  
Antipsychotic Treatment ◽  
Blood Oxygen Level ◽  
Double Blind ◽  
Associate Learning

Abstract Background Recent evidence suggests that cannabidiol (CBD), a non-intoxicating ingredient present in cannabis extract, has an antipsychotic effect in people with established psychosis. However, the effect of CBD on the neurocognitive mechanisms underlying psychosis is unknown. Methods Patients with established psychosis on standard antipsychotic treatment were studied on separate days at least one week apart, to investigate the effects of a single dose of orally administered CBD (600 mg) compared to a matched placebo (PLB), using a double-blind, randomized, PLB-controlled, repeated-measures, within-subject cross-over design. Three hours after taking the study drug participants were scanned using a block design functional magnetic resonance imaging (fMRI) paradigm, while performing a verbal paired associate learning task. Fifteen psychosis patients completed both study days, 13 completed both scanning sessions. Nineteen healthy controls (HC) were also scanned using the same fMRI paradigm under identical conditions, but without any drug administration. Effects of CBD on brain activation measured using the blood oxygen level-dependent hemodynamic response fMRI signal were studied in the mediotemporal, prefrontal, and striatal regions of interest. Results Compared to HC, psychosis patients under PLB had altered prefrontal activation during verbal encoding, as well as altered mediotemporal and prefrontal activation and greater mediotemporal-striatal functional connectivity during verbal recall. CBD attenuated dysfunction in these regions such that activation under its influence was intermediate between the PLB condition and HC. CBD also attenuated hippocampal-striatal functional connectivity and caused trend-level symptom reduction in psychosis patients. Conclusions This suggests that normalization of mediotemporal and prefrontal dysfunction and mediotemporal-striatal functional connectivity may underlie the antipsychotic effects of CBD.

scholarly journals Association Between Brain Activation and Functional Connectivity

2018 ◽  
Vol 29 (5) ◽  
pp. 1984-1996 ◽  
Author(s):  
Dardo Tomasi ◽  
Nora D Volkow
Keyword(s):  
Functional Connectivity ◽  
Brain Activity ◽  
Low Frequency ◽  
Brain Activation ◽  
Blood Oxygen Level Dependent ◽  
Common Source ◽  
Functional Connectivity Density ◽  
Density Mapping ◽  
Human Connectome Project ◽  
Bold Responses

Abstract The origin of the “resting-state” brain activity recorded with functional magnetic resonance imaging (fMRI) is still uncertain. Here we provide evidence for the neurovascular origins of the amplitude of the low-frequency fluctuations (ALFF) and the local functional connectivity density (lFCD) by comparing them with task-induced blood-oxygen level dependent (BOLD) responses, which are considered a proxy for neuronal activation. Using fMRI data for 2 different tasks (Relational and Social) collected by the Human Connectome Project in 426 healthy adults, we show that ALFF and lFCD have linear associations with the BOLD response. This association was significantly attenuated by a novel task signal regression (TSR) procedure, indicating that task performance enhances lFCD and ALFF in activated regions. We also show that lFCD predicts BOLD activation patterns, as was recently shown for other functional connectivity metrics, which corroborates that resting functional connectivity architecture impacts brain activation responses. Thus, our findings indicate a common source for BOLD responses, ALFF and lFCD, which is consistent with the neurovascular origin of local hemodynamic synchrony presumably reflecting coordinated fluctuations in neuronal activity. This study also supports the development of task-evoked functional connectivity density mapping.

scholarly journals The Effect of Movement Amplitude on Activation in Functional Magnetic Resonance Imaging Studies

1999 ◽  
Vol 19 (11) ◽  
pp. 1209-1212 ◽  
Author(s):  
Daniel Waldvogel ◽  
Peter van Gelderen ◽  
Kenji Ishii ◽  
Mark Hallett
Keyword(s):  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Normal Subjects ◽  
Blood Oxygen Level Dependent ◽  
Intensity Increase ◽  
Movement Amplitude ◽  
Blood Oxygen Level ◽  
Sensorimotor Area ◽  
Areas Of Interest ◽  
System Movement

To evaluate the effect of movement amplitude on the “blood oxygen level-dependent effect,” the authors studied six normal subjects while they extended their index finger with two different amplitudes, Images were analyzed using SPM96, In five subjects, the signal intensity increase in the primary sensorimotor area was significantly greater with the larger amplitude movement. In other areas of interest (supplementary motor area, premotor cortex, insula, postcentral area, cerebellum), the large-amplitude movement often showed significant activation when the small-amplitude movement did not. The authors conclude that, in studies of the motor system, movement amplitude needs to be controlled.

scholarly journals Advanced Meditation Alters Resting-State Brain Network Connectivity Correlating With Improved Mindfulness

2021 ◽  
Vol 12 ◽  
Author(s):  
Ramana V. Vishnubhotla ◽  
Rupa Radhakrishnan ◽  
Kestas Kveraga ◽  
Rachael Deardorff ◽  
Chithra Ram ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Network Connectivity ◽  
Blood Oxygen Level Dependent ◽  
Brain Network ◽  
Resting State Functional Connectivity ◽  
Blood Oxygen Level ◽  
Default Mode ◽  
Before And After ◽  
Brain Network Connectivity

Purpose: The purpose of this study was to investigate the effect of an intensive 8-day Samyama meditation program on the brain functional connectivity using resting-state functional MRI (rs-fMRI).Methods: Thirteen Samyama program participants (meditators) and 4 controls underwent fMRI brain scans before and after the 8-day residential meditation program. Subjects underwent fMRI with a blood oxygen level dependent (BOLD) contrast at rest and during focused breathing. Changes in network connectivity before and after Samyama program were evaluated. In addition, validated psychological metrics were correlated with changes in functional connectivity.Results: Meditators showed significantly increased network connectivity between the salience network (SN) and default mode network (DMN) after the Samyama program (p < 0.01). Increased connectivity within the SN correlated with an improvement in self-reported mindfulness scores (p < 0.01).Conclusion: Samyama, an intensive silent meditation program, favorably increased the resting-state functional connectivity between the salience and default mode networks. During focused breath watching, meditators had lower intra-network connectivity in specific networks. Furthermore, increased intra-network connectivity correlated with improved self-reported mindfulness after Samyama.Clinical Trials Registration: [https://clinicaltrials.gov], Identifier: [NCT04366544]. Registered on 4/17/2020.

scholarly journals Differential effects of anesthetics on resting state functional connectivity in the mouse

2019 ◽  
Vol 40 (4) ◽  
pp. 875-884 ◽  
Author(s):  
Hongyu Xie ◽  
David Y Chung ◽  
Sreekanth Kura ◽  
Kazutaka Sugimoto ◽  
Sanem A Aykan ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Chloral Hydrate ◽  
Low Frequency ◽  
Blood Oxygen Level Dependent ◽  
Resting State Functional Connectivity ◽  
Blood Oxygen Level ◽  
Intrinsic Signal ◽  
Optical Intrinsic Signal ◽  
Important Approach

Blood oxygen level-dependent (BOLD) functional MRI (fMRI) is a standard approach to examine resting state functional connectivity (RSFC), but fMRI in animal models is challenging. Recently, functional optical intrinsic signal imaging—which relies on the same hemodynamic signal underlying BOLD fMRI—has been developed as a complementary approach to assess RSFC in mice. Since it is difficult to ensure that an animal is in a truly resting state while awake, RSFC measurements under anesthesia remain an important approach. Therefore, we systematically examined measures of RSFC using non-invasive, widefield optical intrinsic signal imaging under five different anesthetics in male C57BL/6J mice. We find excellent seed-based, global, and interhemispheric connectivity using tribromoethanol (Avertin) and ketamine–xylazine, comparable to results in the literature including awake animals. Urethane anesthesia yielded intermediate results, while chloral hydrate and isoflurane were both associated with poor RSFC. Furthermore, we found a correspondence between the strength of RSFC and the power of low-frequency hemodynamic fluctuations. In conclusion, Avertin and ketamine–xylazine provide robust and reproducible measures of RSFC in mice, whereas chloral hydrate and isoflurane do not.

Functional connectivity during smooth pursuit eye movements

2020 ◽  
Vol 124 (6) ◽  
pp. 1839-1856
Author(s):  
Rebekka Schröder ◽  
Anna-Maria Kasparbauer ◽  
Inga Meyhöfer ◽  
Maria Steffens ◽  
Peter Trautner ◽  
...  
Keyword(s):  
Eye Movements ◽  
Functional Connectivity ◽  
Smooth Pursuit ◽  
Potential Role ◽  
Blood Oxygen Level Dependent ◽  
Smooth Pursuit Eye Movements ◽  
Blood Oxygen Level ◽  
Comprehensive Investigation ◽  
Pursuit Eye Movements ◽  
Healthy Participants

This study provides a comprehensive investigation of blood oxygen level-dependent (BOLD) functional connectivity during smooth pursuit eye movements. Results from a large sample of healthy participants suggest that key oculomotor regions interact closely with each other but also with regions not primarily associated with eye movements. Understanding functional connectivity during smooth pursuit is important, given its potential role as an endophenotype of psychoses.

scholarly journals Subcortical connectivity in dementia with Lewy bodies and Alzheimer's disease

2013 ◽  
Vol 203 (3) ◽  
pp. 209-214 ◽  
Author(s):  
Eva R. Kenny ◽  
John T. O'Brien ◽  
Michael J. Firbank ◽  
Andrew M. Blamire
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Functional Connectivity ◽  
Resting State ◽  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Low Frequency ◽  
Blood Oxygen Level Dependent ◽  
Bold Signal ◽  
Blood Oxygen Level

BackgroundResting-state functional magnetic resonance imaging (fMRI) can be used to measure correlations in spontaneous low-frequency fluctuations in the blood oxygen level-dependent (BOLD) signal which represent functional connectivity between key brain areas.AimsTo investigate functional connectivity with regions hypothesised to be differentially affected in dementia with Lewy bodies (DLB) compared with Alzheimer's disease and controls.MethodFifteen participants with probable DLB, 16 with probable Alzheimer's disease and 16 controls were scanned in the resting-state using a 3T scanner. The BOLD signal time-series of fluctuations in seed regions were correlated with all other voxels to measure functional connectivity.ResultsParticipants with DLB and Alzheimer's disease showed greater caudate and thalamic connectivity compared with controls. Those with DLB showed greater putamen connectivity compared with those with Alzheimer's disease and the controls. No regions showed less connectivity in DLB or Alzheimer's disease v. controls, or in DLB v. Alzheimer's disease.ConclusionsAltered connectivity in DLB and Alzheimer's disease provides new insights into the neurobiology of these disorders and may aid in earlier diagnosis.

Differential neural correlates of reciprocal activation and cocontraction control in dorsal and ventral premotor cortices

2012 ◽  
Vol 107 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Masahiko Haruno ◽  
Gowrishankar Ganesh ◽  
Etienne Burdet ◽  
Mitsuo Kawato
Keyword(s):  
Brain Activity ◽  
Premotor Cortex ◽  
Neural Correlates ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Dorsal Premotor Cortex ◽  
Blood Oxygen Level ◽  
Efficient Control ◽  
Dependent Activity ◽  
The Brain

Efficient control of reciprocal activation and cocontraction of the muscles are critical to perform skillful actions with suitable force and impedance. However, it remains unclear how the brain controls force and impedance while recruiting the same set of muscles as actuators. Does control take place at the single muscle level leading to force and impedance, or are there higher-order centers dedicated to controlling force and impedance? We addressed this question using functional MRI during voluntary isometric wrist contractions with online electromyogram feedback. Comparison of the brain activity between the conditions requiring control of either wrist torque or cocontraction demonstrates that blood oxygen level-dependent activity in the caudo-dorsal premotor cortex (PMd) correlates well with torque, whereas the activity in the ventral premotor cortex (PMv) correlates well with the level of cocontraction. This suggests distinct roles of the PMd and PMv in the voluntary control of reciprocal activation and cocontraction of muscles, respectively.

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