Parotid and submandibular gland sympathetic denervation in Parkinson's disease: Development of a novel analytical method to elucidate the pathophysiology of Parkinson's disease

Summary:
Parkinson’s disease (PD) is a neurodegenerative disorder associated with motor disturbances related to dopaminergic dysfunction but it also has a variety of non-motor symptoms such as autonomic dysfunction. ¹²³I- metaiodobenzylguanidine (MIBG) myocardial scintigraphy (Note 2) is available in Japan as an adjunctive diagnostic method for PD, and it is known that PD and other Lewy body diseases present with cardiac sympathetic denervation. On the other hand, Lewy bodies have been found in peripheral organs such as the major salivary glands and other gastrointestinal tracts and skin, in addition to the heart, but it is unclear at what time the lesions begin to develop. Therefore, the research group adapted the MIBG cardiac scintigraphy examination to test the major salivary glands (parotid and submandibular), where Lewy bodies predominate in the head and neck region, using a new quantitative semi-automated analysis method. Comparing the PD group with the control group, MIBG uptake was significantly lower in the PD group in the early and delayed parotid and delayed submandibular gland images (Table 1). There was no correlation between cardiac and major salivary gland MIBG uptake (Figure 2), which was thought to be due to differences in the degree of neurodegeneration. The results of this research will add a new dimension to our understanding of the pathological progression of PD and may help to elucidate the pathogenesis of the disease.