In several neurodegenerative diseases, such as Parkinson's disease, the progressive loss of neurons of monoaminergic systems leads to the development of characteristic clinical manifestations. Therefore, since the discovery that neurodegenerative phenomena are the basis of these Central Nervous System (CNS) diseases, re-innervation strategies have been studied that would allow to stop or at least slow down neurodegenerative phenomena, restoring lost catecholaminergic transmission. Cell therapy in Parkinson's disease aims to treat motor disorders, but should not affect cognitive disorders that result from pathological alterations external to CNS and affecting other transmission systems, such as noradrenergic and cholinergic. These limitations lead to the search for new approaches based on the use of different cell types, but currently these scenarios still seem far away. The theme of cerebral re-innervation in the treatment of neurodegenerative diseases is at the center of numerous translational and clinical research studies, developed according to various approaches and models, which testify to all the complexity and charm of the subject. Among the possible sources for a catecholamine reinnervation in Parkinson's disease, Superior Cervical Ganglion (SCG) could represent a valid autologous source: however, there is no functional evaluation in the literature that expresses the involvement or not of the ganglion in the neurodegenerative process. This clinical study project is the first and essential phase of a larger project aimed at verifying the possibility of autologous catecholamine reinnervation in degenerative diseases of the CNS using the peripheral catecholamine system and in particular the superior cervical ganglion (GCS). The aim of this project is to evaluate whether the peripheral catecholaminergic system, and in particular the SCG, is involved in the process of neurodegeneration. For this purpose, for an in vivo functional study, the suitability of the PET-CT 68Ga-PSMA examination will be studied in particular.