Contrasting Connectivity of the Ventralis Intermedius and Ventralis Oralis Posterior Nuclei of the Motor Thalamus Demonstrated by Probabilistic Tractography

Neurosurgery ◽  
2011 ◽  
Vol 70 (1) ◽  
pp. 162-169 ◽  
Author(s):  
Jonathan A. Hyam ◽  
Sarah L.F. Owen ◽  
Morten L. Kringelbach ◽  
Ned Jenkinson ◽  
John F. Stein ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Diffusion Tensor ◽  
Motor Area ◽  
Probabilistic Tractography ◽  
Thalamic Nuclei ◽  
Dorsolateral Prefrontal ◽  
Motor Thalamus

Abstract BACKGROUND Targeting of the motor thalamus for the treatment of tremor has traditionally been achieved by a combination of anatomical atlases and neuroimaging, intraoperative clinical assessment, and physiological recordings. OBJECTIVE To evaluate whether thalamic nuclei targeted in tremor surgery could be identified by virtue of their differing connections with noninvasive neuroimaging, thereby providing an extra factor to aid successful targeting. METHODS Diffusion tensor tractography was performed in 17 healthy control subjects using diffusion data acquired at 1.5-T magnetic resonance imaging (60 directions, b value = 1000 s/mm2, 2 × 2 × 2-mm3 voxels). The ventralis intermedius (Vim) and ventralis oralis posterior (Vop) nuclei were identified by a stereotactic neurosurgeon, and these sites were used as seeds for probabilistic tractography. The expected cortical connections of these nuclei, namely the primary motor cortex (M1) and contralateral cerebellum for the Vim and M1, the supplementary motor area, and dorsolateral prefrontal cortex for the Vop, were determined a priori from the literature. RESULTS Tractogram signal intensity was highest in the dorsolateral prefrontal cortex and supplementary motor area after Vop seeding (P > .001, Wilcoxon signed-rank tests). High intensity was seen in M1 after seeding of both nuclei but was greater with Vim seeding (P > .001). Contralateral cerebellar signal was highest with Vim seeding (P > .001). CONCLUSION Probabilistic tractography can depict differences in connectivity between intimate nuclei within the motor thalamus. These connections are consistent with published anatomical studies; therefore, tractography may provide an important adjunct in future targeting in tremor surgery.

scholarly journals Modulation of Fibers to Motor Cortex during Thalamic DBS in Tourette Patients Correlates with Tic Reduction

2020 ◽  
Vol 10 (5) ◽  
pp. 302 ◽  
Author(s):  
Pablo Andrade ◽  
Petra Heiden ◽  
Moritz Hoevels ◽  
Marc Schlamann ◽  
Juan C. Baldermann ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Diffusion Tensor ◽  
Regions Of Interest ◽  
Motor Area ◽  
Probabilistic Tractography ◽  
Cortical Areas ◽  
Centromedian Nucleus ◽  
Deep Brain

Probabilistic tractography in Tourette syndrome (TS) patients have shown an alteration in the connectivity of the primary motor cortex and supplementary motor area with the striatum and thalamus, suggesting an abnormal connectivity of the cortico-striatum-thalamocortical-pathways in TS. Deep brain stimulation (DBS) of the centromedian nucleus–nucleus ventrooralis internus (CM-Voi complex) in the thalamus is an effective treatment for refractory TS patients. We investigated the connectivity of activated fibers from CM-Voi to the motor cortex and its correlation between these projections and their clinical outcome. Seven patients with TS underwent CM-Voi-DBS surgery and were clinically evaluated preoperatively and six months postoperatively. We performed diffusion tensor imaging to display the activated fibers projecting from the CM-Voi to the different motor cortex regions of interest. These analyses showed that the extent of tic reduction during DBS is associated with the degree of stimulation-dependent connectivity between CM-Voi and the motor cortex, and in particular, an increased density of projections to the presupplementary motor area (preSMA). Non-responder patients displayed the largest amount of active fibers projecting into cortical areas other than motor cortex compared to responder patients. These findings support the notion that an abnormal connectivity of thalamocortical pathways underlies TS, and that modulation of these circuits through DBS could restore the function and reduce symptoms.

scholarly journals Using Dual-Site Transcranial Magnetic Stimulation to Probe Connectivity between the Dorsolateral Prefrontal Cortex and Ipsilateral Primary Motor Cortex in Humans

2019 ◽  
Vol 9 (8) ◽  
pp. 177 ◽  
Author(s):  
Matt J.N. Brown ◽  
Elana R. Goldenkoff ◽  
Robert Chen ◽  
Carolyn Gunraj ◽  
Michael Vesia
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Primary Motor Cortex ◽  
Conditioning Stimulus ◽  
Resting Motor Threshold ◽  
Dorsolateral Prefrontal ◽  
Dual Site

Dual-site transcranial magnetic stimulation to the primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC) can be used to probe functional connectivity between these regions. The purpose of this study was to characterize the effect of DLPFC stimulation on ipsilateral M1 excitability while participants were at rest and contracting the left- and right-hand first dorsal interosseous muscle. Twelve participants were tested in two separate sessions at varying inter-stimulus intervals (ISI: 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, and 20 ms) at two different conditioning stimulus intensities (80% and 120% of resting motor threshold). No significant effect on ipsilateral M1 excitability was found when applying a conditioning stimulus over DLPFC at any specific inter-stimulus interval or intensity in either the left or right hemisphere. Our findings suggest neither causal inhibitory nor faciliatory influences of DLPFC on ipsilateral M1 activity while participants were at rest or when performing an isometric contraction in the target hand muscle.

Spatiotemporal features of β-γ phase-amplitude coupling in Parkinson’s disease derived from scalp EEG

Brain ◽  
2020 ◽  
Author(s):  
Ruxue Gong ◽  
Mirko Wegscheider ◽  
Christoph Mühlberg ◽  
Richard Gast ◽  
Christopher Fricke ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Prefrontal Cortex ◽  
Somatosensory Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Primary Motor Cortex ◽  
Rating Scale ◽  
Depth Analysis ◽  
Dorsolateral Prefrontal ◽  
Phase Amplitude

Abstract Abnormal phase-amplitude coupling between β and broadband-γ activities has been identified in recordings from the cortex or scalp of patients with Parkinson’s disease. While enhanced phase-amplitude coupling has been proposed as a biomarker of Parkinson’s disease, the neuronal mechanisms underlying the abnormal coupling and its relationship to motor impairments in Parkinson’s disease remain unclear. To address these issues, we performed an in-depth analysis of high-density EEG recordings at rest in 19 patients with Parkinson’s disease and 20 age- and sex-matched healthy control subjects. EEG signals were projected onto the individual cortical surfaces using source reconstruction techniques and separated into spatiotemporal components using independent component analysis. Compared to healthy controls, phase-amplitude coupling of Parkinson’s disease patients was enhanced in dorsolateral prefrontal cortex, premotor cortex, primary motor cortex and somatosensory cortex, the difference being statistically significant in the hemisphere contralateral to the clinically more affected side. β and γ signals involved in generating abnormal phase-amplitude coupling were not strictly phase-phase coupled, ruling out that phase-amplitude coupling merely reflects the abnormal activity of a single oscillator in a recurrent network. We found important differences for couplings between the β and γ signals from identical components as opposed to those from different components (originating from distinct spatial locations). While both couplings were abnormally enhanced in patients, only the latter were correlated with clinical motor severity as indexed by part III of the Movement Disorder Society Unified Parkinson’s Disease Rating Scale. Correlations with parkinsonian motor symptoms of such inter-component couplings were found in premotor, primary motor and somatosensory cortex, but not in dorsolateral prefrontal cortex, suggesting motor domain specificity. The topography of phase-amplitude coupling demonstrated profound differences in patients compared to controls. These findings suggest, first, that enhanced phase-amplitude coupling in Parkinson’s disease patients originates from the coupling between distinct neural networks in several brain regions involved in motor control. Because these regions included the somatosensory cortex, abnormal phase-amplitude coupling is not exclusively tied to the hyperdirect tract connecting cortical regions monosynaptically with the subthalamic nucleus. Second, only the coupling between β and γ signals from different components appears to have pathophysiological significance, suggesting that therapeutic approaches breaking the abnormal lateral coupling between neuronal circuits may be more promising than targeting phase-amplitude coupling per se.

Connections of the dorsolateral prefrontal cortex with the thalamus: a probabilistic tractography study

2015 ◽  
Vol 38 (6) ◽  
pp. 705-710 ◽  
Author(s):  
Pierre-Jean Le Reste ◽  
C. Haegelen ◽  
B. Gibaud ◽  
T. Moreau ◽  
X. Morandi
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Probabilistic Tractography ◽  
Dorsolateral Prefrontal

scholarly journals TRANSCRANIAL DIRECT STIMULATION IN THE NEUROMODULATION OF CONTROLLING MAIN SYMPTOMS OF PARKINSON’S DISEASE: A CASE STUDY

2022 ◽  
Author(s):  
Letizzia DALL’AGNOL ◽  
Alice Medeiros de SOUZA ◽  
Lilian Campos AMADEU ◽  
Eleni VOSNIADOU ◽  
Fernanda Ishida CORRÊA
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Control ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Primary Motor Cortex ◽  
Motor Coordination ◽  
Neurodegenerative Disorder ◽  
Direct Stimulation ◽  
Dorsolateral Prefrontal

Parkinson’s disease (PD) is a central nervous system neurodegenerative disorder that primarily affects the motor system, decreasing motor coordination, balance and generating tremors, and a progressive loss of everyday mobility, including walking. This study was conducted to verify the effects of Transcranial Direct Current Stimulation (tDCS) on balance, motor control, and the quality of life in Parkinson’s disease patients. The patient received three treatments consisting of 10 sessions of 20 minutes each and a one-week interval between treatments. Active stimulation was applied on the primary motor cortex (M1), the dorsolateral prefrontal cortex (DLPFC), and the dorsolateral prefrontal cortex (D Sham-tDCS. DLPFC stimulation produced the best improvements in terms of motor control, balance, gait, and overall PD symptoms, as evaluated by different scales and questionnaires. As a result, active stimulation of the DLPFC produced superior outcomes and may contribute to treating Parkinson’s disease.

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