The prognostic value of intra-operative observations during thalamotomy for parkinsonian tremor.
Data from 27 thalamotomies were analyzed with respect to possible correlations between certain intra-operative observations and the long-term effect on parkinsonian tremor. Tremor reduction caused by mechanical impact of the electrodes in the target area was not correlated with the long-term effect on the tremor. The same was true for the threshold intensities during the intra-operative electrical stimulation of the target area, stimulation that facilitates and/or inhibits the tremor. In a minority of the patients, all with good long-term results, a combination of a pronounced tremor inhibition from the electrode insertion and a low threshold intensity was observed. Variations in other lesion parameters were not correlated with the outcome. The results are discussed within the framework of a "tremor" vs. a "tonus" mechanism underlying the thalamotomy effect.
Wester
K
K
Department of Neurosurgery, University of Bergen Medical School, Norway.
Hauglie-Hanssen
E
E
D000368:Aged; D001931:Brain Mapping; D004568:Electrodiagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications / Q000503:physiopathology*; D013238:Stereotaxic Techniques; D013787:Thalamic Nuclei / Q000503:physiopathology / Q000601:surgery*; D014202:Tremor / Q000503:physiopathology / Q000601:surgery*