Imaging of subthalamic nucleus and ventralis intermedius of the thalamus
Mov Disord.. 2002-03-01; 17(S3): S123-S129
DOI: 10.1002/mds.10153
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1. Mov Disord. 2002;17 Suppl 3:S123-9. doi: 10.1002/mds.10153.
Imaging of subthalamic nucleus and ventralis intermedius of the thalamus.
Benabid AL(1), Koudsie A, Benazzouz A, Le Bas JF, Pollak P.
Author information:
(1)Department of Clinical and Biological Neurosciences, Institut National de la
Santé et de la Recherche Médicale, Preclinical Neurosciences U-318, Joseph
Fourier University of Grenoble, Hôpital A. Michallon, France.
The techniques of targeting the subthalamic nucleus (STN) and the ventralis
intermedius nucleus (Vim) are similar, only the coordinates are different.
Targeting ideally consists of gathering all data about a target and positioning
the electrode correctly within that target. The electrode should be positioned
within a statistical range of coordinates, where the neuronal firing fits a
given pattern and responds to external stimuli, particularly to proprioceptive
inputs, in a somatotopically organized manner. Moreover, final placement should
provide the best clinical improvement of symptoms under the stimulation
parameters expected to be used in the long term. This latter criterion is by far
the most important, because intraoperative findings indicate the functional
benefit for the patient, which is the ultimate purpose of this surgery. A
variety of radiological modalities are available to provide data for electrode
placement, but each type has its drawbacks. Ventriculography, although safe when
performed accordingly to strict technical procedure, is the most precise method
but provides more indirect targeting and is more invasive than magnetic
resonance imaging (MRI). MRI is the best method for visualizing the STN and, to
some extent, for discerning the Vim, but it is plagued with unpredictable and
nonreproducible deformations that induce a systematic distortion. These
shortcomings no doubt will be corrected in the near future, and the technologies
will better assist us in the proper placement of electrodes, which will provide
the patient with the highest possible benefit.
Copyright 2002 Movement Disorder Society
DOI: 10.1002/mds.10153
PMID: 11948766 [Indexed for MEDLINE]