Hypocretin
(Orexin Test)

Orexins are the common names given to a pair of excitatory neuropeptide hormones.

Sample Type:

CSF

Uses:

CSF hypocretin measurement is used to diagnose one of the major forms of narcolepsy – that associated with cataplexy.

Precautions:

None required

Interfering Factors:

Low values are occasionally found in patients with other neurological diseases associated with sleep disturbance

Pre analytical errors:

• wrong patient preparation

• Improper tube

• clotted sample

• overfilled tube

• underfilled tube

• sample received more than 24 hrs after collection

• mislabeled or unlabeled specimen

corrective action:

• Enquiry before sample collection

• Appropriate tube is selected

• Follow proper order of draw

• Blood samples are mixed properly

• Care is taken during blood collection

• Patient’s name with laboratory no

Post analytical errors:

• Incorrect reference values

• Physician not notified of a panic or critical value

• Incorrect interpretation of lab results by physician

• Incorrect data entry of lab result

Reference Range:

CSF Hypocretin: >100 pg/mL

CSF Hypocretin: > 80 pg/mL (children)