Hypocretin‐1 (orexin‐A) concentrations in cerebrospinal fluid are low in patients with Guillain–Barré syndrome

It is reported that cerebrospinal fluid (CSF) hypocretin‐1 (orexin‐A) concentrations in patients with narcolepsy are significantly low. Human narcolepsy is also known to be closely associated with a specific human histocompatibility leukocyte antigen (HLA), suggesting that autoimmunity is involved in the pathophysiology of the disease. Thus, it is important to know whether hypocretin changes are found in definite neuroimmunological diseases such as multiple sclerosis and Guillain–Barré syndrome (GBS). The results of the present study indicate that some patients with GBS have lower levels of CSF hypocretin‐1.