From Big Medical Encyclopedia

PALLIDOTOMIYA (Latin pallidus pale + grech, tome a section, a section) — the stereotaxic operation consisting in destruction of a pale sphere. It is for the first time made by Spiegel (E. Spiegel) and H. Wycis in 1948 and since then for about 10 years was operation of the choice at parkinsonism (see), the deforming muscular dystonia, double athetosis (see) and other extrapyramidal defeats (see. Extrapyramidal system ). The purpose of operation — destruction of a medial joint of a pale sphere and ansa lenticularis leaving it.

Are necessary for P.'s performance: contrasting of ventricular system of a brain, use of the stereotaxic atlas and the corresponding calculations (see. Stereotaxic neurosurgery ).

Stereotaxic coordinates of a medial joint of a pale sphere: in a side projection — on 4 — 6 mm of a kzada from the rear edge of an interventricular foramen on the line connecting it to a back komissurop, and on 10 — 11 mm ventralny the specified point; in a perednezadny projection — on 16 — 18 mm from the median plane.

Stereotaxic calculations, and also introduction of a cannula (electrode) to the set point need to be made with a big accuracy to avoid damage of the internal capsule located medially from a pale sphere. At the same time it is necessary to consider individual variability of a pale sphere: according to E. M. Margorina (1970), its length hesitates ranging from 22 to 32 mm, width — from 8 to 14 mm, height — from 10 to 15 mm.

Destruction of a pale sphere is made by various methods; most effectively and safely local freezing (see. Cryosurgery ).

The item — an effective method of treatment of many extrapyramidal defeats. However at the beginning of the 60th g of 20 century it was established that stereotaxic destruction of a ventrolateralny kernel of a thalamus (VL) is more effective, than the Item. In this regard P. began to apply less often, and then practically refused it.

Bibliography: Kandel E. I. Parkinsonism and its surgical treatment, M., 1965; Spiegel E. A. a. Wycis H. T. Stereoencephalotomy, Pt 1. Methods and stereotaxis atlas of the human brain, N. Y., 1952.

E. I. Kandel.