THE PATHOLOGY OF THE PARKINSONIAN SYNDROME FOLLOWING ENCEPHALITIS LETHARGICA, WITH A NOTE ON THE OCCURRENCE OF CALCIFICATION IN THIS DISEASE

Abstract

An account is given of the histological findings in two cases of the Parkinsonian syndrome following encephalitis lethargica. The most constant findings were subacute inflammatory changes and recent perivascular hæmorrhages. In one case the substantia nigra showed marked degenerative changes, and in the other this area appeared normal; but large hæmorrhages of arteriosclerotic origin in the basal ganglia considerably modify the negative findings in the substantia nigra in the second case. An account is given of fourteen similar cases reported in the literature, in all of which the substantia nigra was affected. Calcification in the anterior part of the globus pallidus was found in six cases of encephalitis lethargica, in one case as early as the fourth day of the disease. The calcification was found both in the vessel walls and in the form of globules; the occurrence of fat globules was noted in one case, and the relation between these and the calcified globules was studied. A short account is given of other conditions in which calcification occurs in the brain, and the pathogenesis and significance of these changes are discussed. I must express my gratitude to Dr. J. G. Greenfield, Pathologist to the National Hospital for the Paralysed and Epileptic, Queen Square, London, for his valuable advice and great kindness in placing at my disposal a considerable amount of the morbid material which was used; also to Dr. J. P. Martin for permission to examine his sections from Case 5, and lastly to the various members of the staff of the National Hospital for permission to use and publish the notes of the cases which had been under their care.