CSF hypocretin-1 assessment in sleep and neurological disorders.
Concentrations of CSF hypocretin-1 (formerly orexin A) have been measured in many patients with sleep or neurological conditions. Low CSF hypocretin-1 is most predictive of narcolepsy in patients positive for HLA allele DQB1*0602, most of whom have cataplexy. By contrast, the diagnostic significance of low CSF hypocretin-1 is unclear in the presence of acute CNS inflammation or trauma. The clinical usefulness of CSF testing in hypersomnia that is symptomatic of a neurological disorder remains to be evaluated. Determination of CSF hypocretin-1 concentration to diagnose narcolepsy might be most useful in ambulatory patients with cataplexy but with a normal multiple sleep latency test (MSLT) result, or if MSLT is not interpretable, conclusive, or feasible. Because 98% of patients with hypocretin-1 deficiency are positive for HLA DQB1*0602, we suggest that HLA typing is a useful screen before lumbar puncture. Although hypocretin-1 deficiency in narcolepsy might have therapeutic relevance, additional research is needed in this area.
Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA. patrice.bourgin@neurochem.u-strasbg.fr
Patrice
P
Bourgin
Jamie M
JM
Zeitzer
Emmanuel
E
Mignot
D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000134:cerebrospinal fluid*; D009422:Nervous System Diseases / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000503:physiopathology; D009479:Neuropeptides / Q000134:cerebrospinal fluid*; D000068797:Orexins; D012890:Sleep / Q000502:physiology*
C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins