Low levels of ventricular CSF orexin/hypocretin in advanced PD

Neurology. 2003 Aug 26;61(4):540-3. doi: 10.1212/01.wnl.0000078194.53210.48.


The origins of excessive daytime sleepiness in Parkinson disease (PD) are unclear. The authors hypothesize that orexin neurons, a recently identified wake promoting system, could contribute to its pathophysiology. They measured orexin-A/hypocretin-1 concentration in ventricular CSF in 19 parkinsonian patients and compared it with neurologic controls. Orexin levels were lower in patients and decreased with the severity of the disease. The authors suggest that orexin neurons contribute to daytime sleepiness in late stage PD.

MeSH terms

  • Antiparkinson Agents / therapeutic use
  • Arousal / physiology
  • Carrier Proteins / cerebrospinal fluid
  • Cerebral Ventricles
  • Combined Modality Therapy
  • Disorders of Excessive Somnolence / cerebrospinal fluid
  • Disorders of Excessive Somnolence / etiology*
  • Electric Stimulation Therapy
  • Female
  • Humans
  • Intracellular Signaling Peptides and Proteins*
  • Male
  • Neuropeptides / cerebrospinal fluid
  • Neuropeptides / deficiency*
  • Orexins
  • Parkinson Disease / cerebrospinal fluid
  • Parkinson Disease / complications*
  • Parkinson Disease / drug therapy
  • Parkinson Disease / therapy


  • Antiparkinson Agents
  • Carrier Proteins
  • HCRT protein, human
  • Intracellular Signaling Peptides and Proteins
  • Neuropeptides
  • Orexins