It is know that the VIM is situated in the center of the circuits involved in the pathogenis of various type of tremor, both in the context of Parkinsonian tremor and in the context of action tremor. This explains why an action on this nucleus achieves a result on both Parkinsonian tremor and other types of tremor. We use a 4-plots electrode in order to situate the 4 plots within the VIM, along its main axis. This hypothesis tend to be confirm by the results obtained in our patients with action tremor. In this group of patients, the effective points of stimulation were mainly situated higher than the level of AC-PC line.
Thalamic stimulation seems to induce less adverse effects than thalamotomy.
In bilateral stimulation, dysarthria still occur, but is controlled by reducing the intensity of one or both stimulators. In multiple sclerosis patients, all of our complications were only transient. This constitutes one of the major advantages of thalamic stimulation over thalamotomy. Chronic stimulation of VIM appears to be a safer procedure than thalamotomy. This technique may be an alternative treatment for Parkinsonian and essential tremor , especially in patients with previous controlateral thalamotomy.