[Contribution of thalamic somatosensory evoked potentials to stereotaxic thalamometry].
BACKGROUND
In order to use short latency somatosensory thalamic evoked potentials (PES) to locate therapeutic targets in functional surgery, thalamic PES were recorded during stereotactic thalamotomy in 25 patients with Parkinson's disease, using a concentric bipolar semi-micro-electrode, 4 mm in diameter. In the 72 trajectories planned. 628 registers were made, obtaining 314 PES in 55 trajectories. These recordings were divided into 5 groups, according to the electrical variables evaluated in each case (absolute latency, inter-peak latency, absolute amplitude and number of phases).


METHODS
The electrophysiological characteristics of the PES groups obtained, and the spatial representation of these in a tridimensional system of coordinates, is shown. We analyze the sequence of the groups of potentials in each of the trajectories followed.


CONCLUSIONS
We consider that the limit between adjacent nuclear edges, ventral intermediate (Vim)-ventro-caudal (Vc), may be represented by the transition of potentials in group 1 to potentials in group 4 and/or potentials of group 3 to those of group 2. This study shows that thalamic PES are useful for locating targets during stereotactic thalamotomy.
Morales-Chacón
L M
LM
Departamento Neurofisiología Clinica, Centro Internacional de Restauración Neurológica, Ciudad de la Habana, Cuba. cineuro@neuro.sid.cu
Macías-González
R
R
Torres
A
A
Alvarez
L
L
Muñoz
J
J
D000328:Adult; D005073:Evoked Potentials, Somatosensory; D006801:Humans; D008875:Middle Aged; D010300:Parkinson Disease / Q000601:surgery; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D013788:Thalamus / Q000601:surgery*; D014202:Tremor