Increased norepinephrine-associated adrenomedullary inclusions in Parkinson's disease

The association with Parkinson's disease (PD) of adrenomedullary inclusions, known as 'hyaline globules' or 'adrenal bodies', has been reported for over 35 years. However, the common perception has been that adrenomedullary chromaffin cells cannot be recognized as pathological cells in PD. In the present study, we discovered that the number of adrenomedullary inclusions per unit area of the adrenal medulla was larger in PD and other Lewy body disorders (LBD) than in other neurological diseases and controls without any autonomic dysfunctions, and correlated with the duration of LBD. We also showed that the cells with adrenomedullary inclusions are all norepinephrine-secreting chromaffin cells. This was detected by PAS reaction following peroxidase immunohistochemistry of four proteins: chromogranin A, phenylethanolamine N-methyltransferase, S-100 protein and neurofilament protein. We also proved that the components of adrenomedullary inclusions are immunocytochemically different from those of Lewy bodies and Lewy-related neurites, as adrenomedullary inclusions were immunonegative to ubiquitin and alpha-synuclein as well as to the above four proteins. Therefore, contrary to current opinion, the norepinephrine-secreting adrenomedullary chromaffin cell is indeed another type of pathological cell in PD and other LBD.