[Dysfunction of the orexin system in Parkinson's disease].
Traditionally, Parkinson's disease (PD) is associated with the lesion of the substantia nigra and dopamine system dysfunction. However, current studies show the involvement of other CNS regions, which extend far beyond the substantia nigra, in the pathogenesis of PD. The prevalence of altered α-synuclein in PD leads to the dysfunction of several neurotransmitter systems including the orexin system located in the hypothalamus. The involvement of this system in the neurodegenerative process explains some symptoms of PD including daily drowsiness and eating disorders. The authors consider the pathophysiology of the orexin system and its role in the pathogenesis of PD.