First described by English surgeon and apothecary Dr. James Parkinson in 1817, the disease now known as Parkinson disease (PD) was first described in a 66-page treatise entitled An Essay on the Shaking Palsy, a disease he first names “Paralysis Agitans.” PD is a neurodegenerative disease, characterized by abnormal deposition of alpha-synculein. Histopathologically, the brain tissue of those with PD demonstrates eosinophilic cytoplasmic inclusions called Lewy bodies. The Braak hypothesis suggests that the synucleinopathy in idiopathic PD follows a specific pattern with initial deposition seen in dorsal motor nucleus of the vagus that spreads through the brain in a prion-like fashion. The involvement of dopaminergic neurons in the substantia nigra pars compacta leads to the motor signs of idiopathic PD.