EP 78. Probabilistic imaging of motor projections of dentate nucleus as target structure for deep brain stimulation in tremor

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• 作者：Y. Parpaley<sup>asup><sup> ; sup> ; S. Skodda<sup>bsup> ; A. Kowoll<sup>csup>
• 刊名：Clinical Neurophysiology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：127
• 期：9
• 页码：e207-e208
• 全文大小：311 K

文摘

As previously described ( and ), deep brain stimulation of dentate-rubro-thalamo-(cortical) (DRT(C)) pathway, efferent motor projection of dentate nucleus, leads to improvement of tremor symptoms. Visualization of DRT (C), as proposed by several authors ( and ), reconstructs connections between dentate nucleus (DN) and ruber nucleus (RN) using deterministic diffusion tensor tractography. However tracer primate studies show that motor projections read spread more than classically described pathway in ruber nucleus (<span id="bb0015">Dum and Strick, 2003span>). Well known is also that tremor suppressing effects are seen after deep brain stimulation of caudal zona incerta (<span id="bb0020">Fytagoridis et al., 2012span>) (cZI), which is dorsolateral to RN. We propose alternative way of DRT visualization with probabilistic connectivity evaluation between DN and anatomically defined ROI of hand and leg projection of primary motor cortex (PMC) on the ipsilateral side.

sSec_2">Materials and methods

sp010">We included MRI data of 16 Patients with essential tremor. DTI Imaging with 30 directions as well as 3D turbo spin echo and 3D mprage sequences produced on 1,5T Siemens Avanto scanner. Manual segmentation of seed regions of interest (ROI) in DN and in PMC was done as start&ndash;end landmarks of DRT (C). Reconstruction of pyramidal tract is done using PMC-ROI and medulla oblongata ROI. Reconstruction of probabilistic tractography maps was done in FSL Software (FMRIB, Oxford, UK). Tractography results transferred to standard MNI152 space, and mean images calculated (NPM, Mricron Software). Tractography result was analyzed using MNI152 based atlas tools.

sSec_3">Results

sp015">Connectivity maps showed high connectivity values inside of DRT (C), demonstrating similar path distribution and course in brainstem and thalamus. Tractography was able to visualize little connectivity to the contralateral motor cortex because of low resolution to depict fibers in decussation of upper cerebellar peduncle, as already reported from other authors (<span id="bb0025">Jbabdi et al., 2015span>). Crossed fibers located anterolatheral of those, which not cross. Fiber course differed from other tractography results in additional fibers going laterally from rubber nucleus.

sSec_4">Conclusions

sp020">Probabalistic tractography can reconstruct motor projections of DN. Even if more sophisticated to produce, probabilistic connectivity maps provide quantitative connection probability, hotspot of which can be used for stereotactic target planning. Further studies to compare deterministic and probabilistic approach to map DRT(C) are needed.