Hypocretin-1 levels in the cerebrospinal fluid of patients with Percheron artery infarction with or without midbrain involvement A case series

Background: Bilateral paramedian thalamic infarctions (BPTIs) due to artery of Percheron occlusion are known to cause hypersomnia. However, the role of hypocretin-1, a wake-promoting peptide that is located at the lateral hypothalamus, in hypersomnia in these patients remains unclear. Methods: To clarify the role of hypocretin-1 in hypersomnia in patients with BPTIs, hypocretin-1 levels in the cerebrospinal fluid (CSF) were measured in 6 patients with BPTIs: 2 with rostral midbrain involvement (BPT+RMI) and 4 without midbrain involvement (BPT-MI). Results: CSF hypocretin-1 levels were decreased in 2 patients with BPT+RMI and were within normal ranges in 4 patients with BPT-MI. Hypersomnia was noted in all the patients. In one BPT+RMI patient, hypersomnia was improved within 2 weeks and decreased CSF hypocretin-1 levels were reversed (acute phase (on day 9), 109.2pg/mL; chronic phase (at 3 months), 323pg/mL), whereas another BPT+RMI patient who displayed coma in the acute phase had decreased CSF orexin levels (107pg/mL) at day 49 and exhibited severe disability. Conclusion: Hypocretin deficiency was not involved in hypersomnia observed in BPT-MI patients; however, CSF hypocretin-1 levels were reduced in BPT+RMI patients. Reduced CSF hypocretin-1 levels in the chronic phase may possibly predict a poor clinical outcome in patients with Percheron artery infarction.