The Pathology of Certain Medullary Nuclei in Parkinsonism

DESPITE a considerable amount of research the locus of the essential pathological lesion of Parkinsonism remains in doubt. The neostriatum and the substantia nigra are favoured sites, but lesions have been described in many other regions of the nervous system, including the medulla oblongata. However, there does not appear to be unanimity of opinion concerning medullary abnormalities in Parkinsonism. Because of this, and because lesions of the medulla could explain some of the autonomic manifestations of Parkinsonism, it was determined to investigate the pathology of this region, with particular reference to the dorsal vagal nucleus, the hypoglossal nucleus and the nucleus ambiguus. The result of this study is now reported. HISTORICAL BACKGROUND Though he had examined no pathological material, Parkinson (1817), in his "An Essay on the Shaking Palsy, " suggested that the cause of the condition he described was "A diseased state of the medulla spinalis, in that part which is contained in the canal formed by the superior cervical vertebras, and extending, as the disease proceeds, to the medulla oblongata." He expanded on the latter part of this hypothesis thus: "From the impediment to speech, the difficulty in mastication and swallowing, the inability to retain, or freely to eject, the saliva, may with propriety be inferred an extension of the morbid change upward through the medulla spinalis to the medulla oblongata, necessarily impairing the powers of the several nerves derived from that portion into which the morbid change may have reached." Pye-Smith (1888) noted that the floor of the fourth ventricle appeared abnormal in a case of Parkinsonism. Lewy (1913) described cell destruc-tion in the Parkinsonian dorsal vagal nucleus with the presence of bizarre by guest on Septem