Superior Cervical Ganglion in Parkinson's Disease

Inclusion Criteria: * Patients affected with Parkinson Disease according to the criteria defined by the Movements Disorder Society Exclusion Criteria: * Unambiguous cerebellar abnormalities, such as cerebellar gait, limb ataxia, or cerebellar oculomotor abnormalities (eg, sustained gaze-evoked nystagmus, square wave macro jerks, hypermetric saccades) * Palsy of vertical descending supranuclear gaze or selective slowing of vertical descending saccades * Diagnosis of probable behavioral variant of frontotemporal dementia or primary progressive aphasia, defined according to consensus criteria, within the first 5 years of the disease * Parkinsonian features limited to the lower limbs for more than 3 years * Treatment with a dopamine receptor blocker or dopamine-reducing agent at a dose and time consistent with drug-induced parkinsonism * Absence of observable response to high-dose levodopa despite at least moderate disease severity * Unequivocal cortical sensory deficit (i.e., graphesthesia, stereognosis with intact primary sensitivities), clear ideomotor apraxia of limbs, or progressive aphasia * Normal functional neuroimaging of the presynaptic dopaminergic system * Documentation of an alternative condition known to induce parkinsonism and plausibly related to the patient's symptoms, or, expert medical opinion that, based on the full diagnostic evaluation, believes that an alternative syndrome is more likely than Parkinson Disease