A Simple Method for Obtaining Stereotaxic Biopsies from the Human Basal Ganglia

The importance of the stereotactic method for obtaining small samples from pre-determined structures in the brain has been emphasized on numerous occasions although only a few studies have ensued. A simple method was described by Kalyanaraman and Gillingham in 1964 and in Newcastle upon Tyne more recently we developed a particularly simple instrument and technique which will remove a cylinder of tissue in a condition suitable for electron microscopy and in sufficient amount for most relevant biochemical analyses. The biopsy cannula is illustrated in Fig. 1 and consists of a tube 19.5 ems long with an outer diameter of 2 mm and an inner diameter of 0.7 mm A stilette lies within the cannula extending to the sharpened tip. The instrument is introduced to a point 3–4 mm above the area to be examined when the stilette is removed from the cannula which is then introduced in a rotatory way with the isolation of a small cylinder of brain tissue. A three-way tap and syringe is then attached and a vacuum produced inside the cannula which holds the biopsy in place while the instrument is withdrawn from the patient and stereotaxic frame. The biopsies are expressed gently into fixative for electron microscopy by slight air pressure from the syringe; alternatively, they can be frozen for biochemical studies or otherwise prepared.