Electroanatomical observations on the ventro caudal parts of the thalamus according to the facts of stereotactic stimulation in man

The electroanatomy of the caudal nuclei of the thalamus was studied in 23 patients, who underwent stereotactical procedures for the treatment of intractable pain or Torticollis. As in the observations on the ventro oral nucleus of the thalamus, the dominant thalamus when stimulated would produce effects on speech. Nearly all stimulations produced synchronic muscular contractions together with sensory effects in the corresponding region. Usually a large region of the body was affected at the same time. The topographical arrangement differed from the arrangement in the ventro oral nucleus of the thalamus; the face and the inside of the mouth and throat were located highest orally and more medially and anteriorly, corresponding to the nucleus Flechsig and its borderline to the centre median. The leg was posterior, most lateral and deepest ventrally, the other body regions were arranged in between. Stimulation of the VJM produced torsion movements only. Coagulation in the dominant hemisphere often had the consequence of a long lasting Korsakov syndrom. Vegetative effects were much less outspoken than in the anterior parts of the thalamus.