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Reversible Heat Lesions with Radiofrequency Current

A Method of Stereotactic Localization

Jerald S. Brodkey, Yuji Miyazaki, Frank R. Ervin and Vernon H. Mark

remembered that modern technology continually is developing techniques for the production and precise control of many different forms of energy. The recent developments of lasers and masers immediately come to mind. It is not inconceivable that before too long readily obtainable heat-energy sources will be available to the surgeon, and that these may be such that they could be focused on an intracranial target from a source entirely external to the head and which would require no other operative procedure. Such a technique could well depend upon the production of a

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John L. Fox

angiography, 34, 63, 88, 89, 314, 335, 336, 620, 700 and local freezing. 120, 121, 363, 386, 556 Following pulsed laser radiation to the brain immediate changes in the blood-brain barrier to fluorescein occur. 292 The relationship between activity of convulsive seizures and the simultaneous passage of dyes and ions across the blood-brain barrier is unknown. 522 Why a substance like trypan blue can stain other body cells but can not pass the blood-brain barrier has been questioned. Such electronegative acid dyes are protein-bound in plasma and as such can pass neither

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John L. Fox, Jude R. Hayes, Marvin N. Stein, Robert C. Green and Roy Paananen

O ne of the outstanding scientific advances of this decade in the field of electro-optics has been the development of the laser beam. The state of the art has progressed so rapidly that laser devices with pulsed powers of 1 billion watts or with continuous wave (CW) power of 1000 watts are available. By focusing the laser beam, power-densities of 10 12 W/cm 2 of pulsed energy and 10 6 W/cm 2 of CW energy are available for experimentation. Because we need to know the effects of laser energy on biological tissues from the point of view of public health

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of Pulsed and Continuous Wave Laser Radiation John L. Fox Jude R. Hayes Marvin N. Stein Robert C. Green Roy Paananen August 1967 27 2 126 137 10.3171/jns.1967.27.2.0126 Movement of Sodium-22, Radioiodinated Protein, and Tritiated Water from the Cisterna Magna into the Cerebrovascular Circulation George Paulson John P. Kapp August 1967 27 2 138 141 10.3171/jns.1967.27.2.0138 Traumatic Thrombosis of Dural Venous Sinuses in Closed Head Injuries Murl E. Kinal August 1967 27 2 142 145 10.3171/jns.1967.27.2.0142 Cerebral Lesions Produced in Rats by

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Barry A. Siegel, Rebecca K. Studer and E. James Potchen

this model. Other workers have also noted increased radioactive sodium uptake in edematous brain resulting from cold injury, 3 laser irradiation, 4 and hypercapnic hypoxia. 1 However, it is interesting that the relative specific activity in embolized brains differs little from control values. This observation suggests that the exchange of radioactive sodium within the enlarged brain sodium space is not greatly accelerated. In addition, the values for the 24-hour equilibration spaces where the relative specific activities exceed unity suggest that, once 22 Na is

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Shelley Wernick and Oscar Sugar

-Operative Complications in Neurosurgical Practice: Recognition, Prevention, and Management Baltimore , Williams & Wilkins , 1967 Horwitz NH, Rizzoli HV: Post-Operative Complications in Neurosurgical Practice: Recognition, Prevention, and Management. Baltimore, Williams & Wilkins, 1967 7. Laser EC : Basic mechanisms of contrast media reactions: theoretical and experimental considerations. Radiology 91 : 63 – 65 , 1968 Laser EC: Basic mechanisms of contrast media reactions: theoretical and experimental considerations. Radiology

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Interstitial gamma irradiation by 198Au of the pituitary in diabetic retinopathy

Selective growth hormone blockade and ocular results

Claude Schaub, Gabor Szikla, Pierre Drouin, Marie-Thérèse Bluet-Pajot, Luc Mejean, Gerard Debry and Jean Talairach

years by the same ophthalmologist in the same diabetes center without associated laser photocoagulation. In accordance with the Hammersmith Grading System, ocular data are expressed in number of eyes. Three patients had unilateral blindness before Stereo-GIHF so only 59 eyes were included. The preoperative assessment shows three different groups, according to the severity of retinopathy components. The postoperative changes in the three groups are shown in Figs. 3 to 5 . Fig. 3. Group 1. Ocular response before (hatched bar) , and after (white bar) Stereo

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Joseph C. Maroon, William O. Bank, Burton P. Drayer and Arthur E. Rosenbaum

aspirating needle can be inserted. These instruments must fit snugly through the cannula, however, otherwise a core of brain is obtained with the outer guide thus interfering with histological interpretation. Most EMI scanners still use a water bath, and it has been necessary to remove and reinsert the patient's head four times or more into the scanner during the procedure. Newer scanners and updated units use wedges and special algorithms so that head positioning is not encumbered by the water bag. Precise trajectory can be further aided with a lowerpower laser

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Edward Neuwelt and Dennis Doherty

lyse any red cells present. An aliquot of the RBC-free cell suspension was then added to the instrument and 10,000 cells counted. The instrument assigned each cell to one of 100 different channels, according to its absorbance of the laser beam. 14 After all 10,000 cells were counted, a printout was obtained listing the number of cells assigned to each channel. Since cell size bears a direct relation to laser beam absorbance, the instrument provided an accurate profile of the size of various cells in a suspension. Results Intrathecal Infusion of Xenogenic

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Scanner includes a unique multiplanar reconstruction program which gives “numerous orthogonal displays” as well as a stereo pairs display for the “three dimensional” information discussed in the paper. In addition, a low-power laser localizing beam and computer-controlled tabletop are integral components of the system. Notwithstanding this oversight, Pfizer Medical Systems welcomes quality reports such as this, which promote the direct involvement of the prime “end user” of computerized tomographic scanning: the neurosurgeon. Neurosurgical Forum: Letters