Hierarchical Dynamic Causal Modeling of Resting-State fMRI Reveals Longitudinal Changes in Effective Connectivity in the Motor System after Thalamotomy for Essential Tremor

Pae, Chongwon; Friston, Karl J.; Jang, Changwon; Razi, Adeel; Zeidman, Peter; Chang, Won Seok; Chang, Jin Woo

doi:10.3389/fneur.2017.00346

Cited by 42 publications

(53 citation statements)

References 49 publications

(59 reference statements)

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“…Recently the rise of MRI-guided high-intensity focused ultrasound (MRgFUS) thermal ablation technique to produce a thalamotomy allowed the chance to use fMRI to study the changes in the brain network caused by a focal lesion. Two rs-fMRI studies performed in drug-resistant ET patients treated with MRgFUS, confirmed connectivity changes in the motor tremor network and not only in the target region 49,50 .…”

Section: Discussionmentioning

confidence: 68%

Cerebello-thalamo-cortical network is intrinsically altered in essential tremor: evidence from a resting state functional MRI study

Nicoletti

Cecchi²,

Pesaresi³

et al. 2020

Sci Rep

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Cerebello-thalamo-cortical network is suggested to be involved in the pathophysiology of Essential Tremor (ET). 23 patients with ET and 23 matched HC underwent a 3T-MRI with acquisition of a resting state sequence. Connectivity was investigated using a seed-based regression analyses approach. In ET patients were observed: Reduced connectivity between left primary motor cortex (M1) seed and right premotor cortex and cerebellum and bilateral premotor, parietal areas, supplementary motor area (SMA); Increased connectivity between left somatosensory cortex (S1) seed and parietal areas, M1, premotor cortex, SMA; reduced connectivity of this seed with cerebellum. Increased connectivity of SMA seed with premotor cortex and decreased with parietal and precentral areas; Increased connectivity between left thalamus seed and cerebellum; Reduced connectivity between right cerebellum seeds and other cerebellar areas, precentral and premotor areas. ET showed altered connectivity within the cortical sensory-motor network and between cerebral cortex and cerebellum. The increased connectivity between cerebellum and thalamus is consistent with their crucial role in tremor generation. These findings support the dynamical entrainment of multiple central oscillators throughout the cerebello-thalamo-cortical network in ET. This evidence is strengthened by the finding that this network is altered also when the core symptom is absent.

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Section: Discussionmentioning

confidence: 68%

Cerebello-thalamo-cortical network is intrinsically altered in essential tremor: evidence from a resting state functional MRI study

Nicoletti

Cecchi²,

Pesaresi³

et al. 2020

Sci Rep

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“…Furthermore, microstructural changes were measured 3 months after tcMRgFUS thalamotomy. Although it has been proposed that functional changes stabilize between 1 week and 3 months after tcMRgFUS thalamotomy (Park et al, ), how these changes behave at longer follow‐ups has not yet been explored. Characterization of microstructural changes after longer periods is required to better describe long‐lasting effects and their correlation to clinical benefit, and to see if the resolution of the side effects is related to the shrinkage of the lesion, or to other distant effects, such as any contralateral compensatory mechanisms.…”

Section: Discussionmentioning

confidence: 99%

Microstructural changes of the dentato‐rubro‐thalamic tract after transcranial MR guided focused ultrasound ablation of the posteroventral VIM in essential tremor

Pineda‐Pardo

Martínez‐Fernández

Rodríguez‐Rojas

et al. 2019

Human Brain Mapping

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Essential tremor is the most common movement disorder in adults. In patients who are not responsive to medical treatment, functional neurosurgery and, more recently, transcranial MR‐guided focused ultrasound thalamotomy are considered effective therapeutic approaches. However, the structural brain changes following a thalamotomy that mediates the clinical improvement are still unclear. In here diffusion weighted images were acquired in a cohort of 24 essential tremor patients before and 3 months after unilateral transcranial MR‐guided focused ultrasound thalamotomy targeting at the posteroventral part of the VIM. Microstructural changes along the DRTT were quantified by means of probabilistic tractography, and later related to the clinical improvement of the patients at 3‐months and at 1‐year after the intervention. In addition the changes along two neighboring tracts, that is, the corticospinal tract and the medial lemniscus, were assessed, as well as the relation between these changes and the presence of side effects. Thalamic lesions produced local and distant alterations along the trajectory of the DRTT, and each correlated with clinical improvement. Regarding side effects, gait imbalance after thalamotomy was associated with greater impact on the DRTT, whereas the presence of paresthesias was significantly related to a higher overlap between the lesion and the medial lemniscus. This work represents the largest series describing the microstructural changes following transcranial MR‐guided focused ultrasound thalamotomy in essential tremor. These results suggest that clinical benefits are specific for the impact on the cerebello‐thalamo‐cortical pathway, thus reaffirming the potential of tractography to aid thalamotomy targeting.

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“…The columns of the A matrix denote the region of neuronal activity origin and the rows denote the region being influenced. The estimated self-connection values, diagonal elements of the A matrix, in the spDCM output have units of Hz after exponentiation and multiplication by À0.5 (Park et al, 2017). Positive estimated self-connections indicate greater self-inhibition, while negative estimated self-connections represent less self-inhibition with respect to the prior (Park et al, 2017).…”

Section: General Linear Model and Region Of Interest Extractionmentioning

confidence: 99%

“…The estimated self-connection values, diagonal elements of the A matrix, in the spDCM output have units of Hz after exponentiation and multiplication by À0.5 (Park et al, 2017). Positive estimated self-connections indicate greater self-inhibition, while negative estimated self-connections represent less self-inhibition with respect to the prior (Park et al, 2017). Extrinsic connections, offdiagonal elements of the A matrix, have units of Hz and are excitatory when positive and inhibitory when negative.…”

Section: General Linear Model and Region Of Interest Extractionmentioning

confidence: 99%

Effective Connectivity Within the Default Mode Network in Left Temporal Lobe Epilepsy: Findings from the Epilepsy Connectome Project

et al. 2019

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The Epilepsy Connectome Project examines the differences in connectomes between temporal lobe epilepsy (TLE) patients and healthy controls. Using these data, the effective connectivity of the default mode network (DMN) in patients with left TLE compared with healthy controls was investigated using spectral dynamic causal modeling (spDCM) of resting-state functional magnetic resonance imaging data. Group comparisons were made using two parametric empirical Bayes (PEB) models. The first level of each PEB model consisted of each participant's spDCM. Two different second-level models were constructed: the first comparing effective connectivity of the groups directly and the second using the Rey Auditory Verbal Learning Test (RAVLT) delayed free recall index as a covariate at the second level to assess effective connectivity controlling for the poor memory performance of left TLE patients. After an automated search over the nested parameter space and thresholding parameters at 95% posterior probability, both models revealed numerous connections in the DMN, which lead to inhibition of the left hippocampal formation. Left hippocampal formation inhibition may be an inherent result of the left temporal epileptogenic focus as memory differences were controlled for in one model and the same connections remained. An excitatory connection from the posterior cingulate cortex to the medial prefrontal cortex was found to be concomitant with left hippocampal formation inhibition in TLE patients when including RAVLT delayed free recall at the second level.

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Hierarchical Dynamic Causal Modeling of Resting-State fMRI Reveals Longitudinal Changes in Effective Connectivity in the Motor System after Thalamotomy for Essential Tremor

Cited by 42 publications

References 49 publications

Cerebello-thalamo-cortical network is intrinsically altered in essential tremor: evidence from a resting state functional MRI study

Cerebello-thalamo-cortical network is intrinsically altered in essential tremor: evidence from a resting state functional MRI study

Microstructural changes of the dentato‐rubro‐thalamic tract after transcranial MR guided focused ultrasound ablation of the posteroventral VIM in essential tremor

Effective Connectivity Within the Default Mode Network in Left Temporal Lobe Epilepsy: Findings from the Epilepsy Connectome Project

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