Attempts to reproduce amyotrophic lateral sclerosis in laboratory animals by inoculation of Schu virus isolated from a patient with apparent amyotrophic lateral sclerosis.

A virus isolated from the CSF of a patient who had amyotrophic lateral sclerosis for 7 years, and prolonged pleocytosis in the CSF, was adapted to suckling mouse brain by subsequent serial blind passages. This Schu virus belongs to the tick-borne encephalitis complex of the genus Flavivirus (Togaviridae). Suckling mouse brain homogenate of the 13th passage was used for transmission experiments in various species of laboratory animals. Golden hamsters infected subcutaneously fell ill after a number of months, lost weight, and had paresis of the legs. Histologically they had petechial hemorrhages in different parts of the CNS and inflammatory changes in the gray substance of the spinal cord. Pilot studies with repeated inoculations of small doses of different flavivirus strains suggest a course of the disease in experimental animals which resembles slow-virus infections insofar as no encephalitis is produced and degenerative changes of the anterior horn cells prevail over inflammatory signs in the spinal cord. After intracerebral application of Schu virus, cynomolgus monkeys developed the typical lesions of togavirus panencephalitis with epileptic seizures, ataxia, and paresis. After subcutaneous application, the virus seems to spread along peripheral nerves to anterior spinal roots and spinal cord, where mainly motor neurons of the anterior horn are damaged, and from there to the brain. The histological findings are such that one may assume the disease of the patient was due to the infection with the virus isolated from his CSF. Therefore, the hypothesis may be advanced that at least some of the cases diagnosed as amyotrophic lateral sclerosis are due to a togavirus infection.

[X-ray studies of the brain as a basis for stereotaxy (author's transl)]. / Die stereotaktische Orientierung im menschlichen Hirn an Hand röntgenologischer Befunde

All attempts to reconstruct the topography of the brain in the living from studies of animal material are handicapped by technical difficulties. The best method is to compare exact X-ray pictures, which have been taken under stereotactic conditions. From a large collection of such X-rays the authors have composed contours of the internal table of the skull and of the ventricles, which best match the brains, selected for the Schaltenbrand-Bailey sterotactic atlas. For practical purposes these contours were combined with the transparent overlays for the nomenclature and the border lines of the different parts of the basal ganglia, which have been used in the myelin sections part of the atlas. A comparison of our sagittal series with the new X-ray findings shows, that the sagittal schemata of the atlas represent an extreme variation in the position of the Meynert axis and of the contours of the 4th ventricle. We have chosen a new axis system for the hindbrain, which corresponds to the average of our brains in constructing a new set of typical overlays for the atlas. The contour of the posterior fossa had to be completed. An independent axis system dor the structures of the 4th ventricle was developed, consisting of the base of the 4th ventricle, and a tangent, to the upper contour of the pons. In sterotactic procedures the axis systems for the forebrain and the hindbrain should be used independently. The results obtained are the basis for a new series of lantern slides which can be projected against the X-ray pictures with the Würzburg stereotactic equipment. In the course of this investigation we discovered a source of error. When air enters the puncture hole of the dura, the brain may sink back, so with the patient lying on his back, all structures may shift a few millimeters towards the occipital region. When the patient is lying on his side, as during an approach to the amygdala through the planum temporale, the ventricular system may collapse, so that almost no air is visible in the ventricles and the 3rd ventricle may appear to be in the lower hemisphere, the dislocation being more than 5-8 mm. But filling the ventricle with air through the ventricular catheter is sufficient to blow up the brain and to restore the normal topography.