Neurosurgery: Stereotactic Neurosurgery for Parkinson's Disease

The Council on Scientific Affairs of the California Medical Association presents the following epitomes of progress in neurosurgery. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and clinical importance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of progress in medicine, whether in their own field of special interest or another.The epitomes included here were selected by the Advisory Panel to the Section on Neurosurgery of the California Medical Association, and the summaries were prepared under the direction of John H. Neal, MD, and the panel.     

Epidemiology of head injury.

To find the incidence of the various types of head injury that occur in the community separate yearly rates (per 10(5) population in Scotland) for deaths, admissions to hospital, and attendance at accident and emergency departments were estimated and compared (when possible) with rates in England and Wales and the United States. Hospital admissions provide the best data for comparing incidences in different geographical areas and rates of attendance at accident and emergency departments the most reliable guide to incidences in the community. Admission rates, however, vary with local facilities and policies, and these also determine the proportion of patients referred to regional neurosurgical units. Such epidemiological data must be sought both for planning health care for head injury and for monitoring the effectiveness of services.     

Experimental studies in head injury

Summary A method to produce pressure pulses useful in percussion concussion experiments in animals is presented. The pulses can be varied within the range found in acceleration impact pressure patterns in human cadaver skulls.The transmission and distortion of the produced pressure pulses were studied in waterfilled models and in rabbit skulls. Positive pressures are more easily transmitted than negative pressures, particularly through the rabbit skull. The possibility to cause local brain injuries with short negative pressures at the site of input is demonstrated. The vital and cytochemical response of the living animal to pressure pulses will be published elsewhere.This work was supported by grants from the Medical Faculty of the University of Gothenburg, Statens Trafiksäkerhetsråd and Försäkringsaktiebolaget Fylgia.