Cerebello-Thalamo-Cortical Tract Reorganization After MRgFUS Thalamotomy in Essential Tremor
Poster No:
36
Submission Type:
Abstract Submission
Authors:
Neeraj Upadhyay1,2, Veronika Purrer2,3, Angelika Maurer1, Marcel Daamen1,2, Valeri Borger4, Alexander Radbruch5, Ulrike Attenberger6, Ullrich Wuellner3, Henning Boecker1,2
Institutions:
1Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Bonn, NRW, Germany, 2Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), Bonn, NRW, Germany, 3Department of Neurology, University Hospital Bonn, Bonn, NRW, Germany, 4Department of Neurosurgery, University Hospital Bonn, Bonn, NRW, Germany, 5Department of Neuroradiology, University Hospital Bonn, Bonn, NRW, Germany, 6Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Bonn, NRW, Germany
First Author:
Neeraj Upadhyay
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology|Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)
University Hospital Bonn, Bonn, NRW, Germany|Bonn, NRW, Germany
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology|Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)
University Hospital Bonn, Bonn, NRW, Germany|Bonn, NRW, Germany
Co-Author(s):
Veronika Purrer
Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)|Department of Neurology, University Hospital Bonn
Bonn, NRW, Germany|Bonn, NRW, Germany
Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)|Department of Neurology, University Hospital Bonn
Bonn, NRW, Germany|Bonn, NRW, Germany
Angelika Maurer
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology
University Hospital Bonn, Bonn, NRW, Germany
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology
University Hospital Bonn, Bonn, NRW, Germany
Marcel Daamen
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology|Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)
University Hospital Bonn, Bonn, NRW, Germany|Bonn, NRW, Germany
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology|Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)
University Hospital Bonn, Bonn, NRW, Germany|Bonn, NRW, Germany
Ulrike Attenberger
Department of Diagnostic and Interventional Radiology, University Hospital Bonn
Bonn, NRW, Germany
Department of Diagnostic and Interventional Radiology, University Hospital Bonn
Bonn, NRW, Germany
Henning Boecker
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology|Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)
University Hospital Bonn, Bonn, NRW, Germany|Bonn, NRW, Germany
Clinical Functional Imaging Group, Department of Diagnostic and Interventional Radiology|Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE)
University Hospital Bonn, Bonn, NRW, Germany|Bonn, NRW, Germany
Introduction:
The cerebello-thalamo-cortical tract (CTCT) exhibits pathophysiological disturbances in individuals with essential tremor (ET) when compared to healthy subjects (Gallay et al., 2008). Existing research suggests that both Deep Brain Stimulation and Magnetic Resonance-guided Focused Ultrasound (MRgFUS) (Zesiewicz et al., 2005) are effective interventions for managing tremor activity in drug-resistant ET patients (Giordano et al., 2020; Agrawal et al., 2021; Miller et al., 2022). MRgFUS achieves this by creating a permanent focal brain lesion in the ventral intermediate nucleus (VIM) via ultrasound-induced thermal ablation (Chazen et al., 2018).
In response to localized tissue damage, microstructural reorganization of white matter tracts (Pineda-Pardo et al., 2019; Sammartino et al., 2019) may occur in terms of Wallerian degeneration (Rotshenker, 2011) or compensatory rewiring of neural connections . Therefore, it is crucial to comprehend the microstructural changes within the CTCT associated with MRgFUS thalamotomy in longitudinal studies.
In response to localized tissue damage, microstructural reorganization of white matter tracts (Pineda-Pardo et al., 2019; Sammartino et al., 2019) may occur in terms of Wallerian degeneration (Rotshenker, 2011) or compensatory rewiring of neural connections . Therefore, it is crucial to comprehend the microstructural changes within the CTCT associated with MRgFUS thalamotomy in longitudinal studies.
Methods:
Twenty-seven ET patients (68.7±10.25 years; 19 males and 8 females) underwent VIM MRgFUS, including 24 right-hand dominant and three left-hand dominant tremor patients. Before, 1 month and 6 months after MRgFUS treatment, clinical as well as T1-weighted and Diffusion Tensor Imaging (DTI) data were acquired at 3T (Philips Achieva scanner with 8-channel head coil). We included part B and subscores of the upper extremity tremor rating of part A of the Clinical Rating Scale for Tremor to create a modified outcome measure ("CRST-AB subscale") consisting of 7 items resulting in a maximum of 28 points. Scores were calculated for the treated and non-treated side separately. Probabilistic tractography was performed to map the CTCT (Pohl et al., 2022) taking the ipsilateral dentate nucleus as seed and contralateral precentral gyrus as target to assess probabilistic fiber density (FD). Furthermore, weighted least square tensor fitting was performed to obtain fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) measures of microstructural integrity using the FDT pipeline within the FSL toolbox (https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/FDT). The various maps of fiber density and white matter integrity from left dominant tremor subjects were swapped from left to right. Finally, the measures were compared by implementing pairwise comparisons between different time points using FSL's randomise approach (https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/Randomise). Significant results were reported at p<0.05 corrected for multiple comparisons using the threshold-free cluster enhancement (TFCE) method.
Results:
Significant tremor reduction was observed 1 month (M±SD: 5.02 ± 4.27; t(26) = -13.8, p <0.001, Cohen's d = -2.65) and remained reduced 6 months after MRgFUS (M±SD = 5.85 ± 4.56; t(26) = -13.4, p <0.001, Cohen's d = -2.58), relative to before MRgFUS treatment (M±SD = 18.78 ± 4.27) .
We observed decreased CTCT fiber density at 1 as well as 6 months after, as compared to before MRgFUS (Figure 1a). Microstructural integrity in terms of FA was reduced 1 month and, though with smaller cluster size, 6 months after MRgFUS (Figure 1b). Similarly, a reduction was observed in AD 1 month after MRgFUS (Figure 1c). Conversely, both AD (Figure 1c) and RD (Figure 1d) were increased at 6 months at the distal part of the CTCT tract (between thalamus and precentral gyrus).
We observed decreased CTCT fiber density at 1 as well as 6 months after, as compared to before MRgFUS (Figure 1a). Microstructural integrity in terms of FA was reduced 1 month and, though with smaller cluster size, 6 months after MRgFUS (Figure 1b). Similarly, a reduction was observed in AD 1 month after MRgFUS (Figure 1c). Conversely, both AD (Figure 1c) and RD (Figure 1d) were increased at 6 months at the distal part of the CTCT tract (between thalamus and precentral gyrus).
·Figure 1
Conclusions:
In line with a previous report (Mazerolle et al., 2021), this study reports reduced fiber density and microstructural white matter integrity (FA) longitudinally in the CTCT of the treated side. Moreover, increases in AD and RD at 6 months after MRgFUS were found in distal parts of the CTCT of the treated side, suggesting a chronic degeneration leading to axonal damage (Song et al., 2003) or demyelination (Song et al., 2002), respectively.
Brain Stimulation:
Invasive Stimulation Methods Other 1
Disorders of the Nervous System:
Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s) 2
Keywords:
Degenerative Disease
MRI
Neurological
ULTRASOUND
1|2Indicates the priority used for review
Provide references using author date format
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