CSF hypocretin level in patients with Kleine-Levin syndrome

Abstract

Kleine-Levin syndrome (KLS) is a rare disease with symptoms that include episodic hypersomnia, cognitive and behavioral disturbances. Its pathogenesis is now unknown. Hypocretin levels were studied in KLS patients to determine the role of hypocretin in KLS. CSF samples were collected at 10:00–13:00 from 42 patients diagnosed with KLS in Peking university People’s hospital from 2002 to 2012. 53 control CSF samples were collected in Peking university people’s hospital. 21 CSF samples were collected from KLS patients during remissions and 25 CSF samples during episodes. Hypocretin was tested with 125I radioimmunoassay kit. Independent t test and paired t test were used to assess hypocretin levels between KLS patients and controls. No significant difference was found between non-episodic KLS patients and controls (303.45 ± 18.48 versus 320.58 ± 12.04 pg/ml, p = 0.448). Hypocretin levels, however, were lower in KLS patients during episodes, as compared with controls (185.46 ± 13.58 versus 320.58 ± 12.04 pg/ml, p = 0.000). Significant difference was also found in KLS patients between episodes and remissions (197.42 ± 16.40 versus 303.91 ± 22.34 pg/ml, n = 16, p = 0.000). KLS patients have lower hypocretin levels during episodes than controls and hypocretin levels are increased when they recovery. Therefore, we hypothesis that hypocretin may play a role in KLS pathogenesis. Fang Han Han Yan, Yanan Liu, Jingyu Wan, Xiaozhe Zhang, Wei Zhou, Yan Hu, Xiaosong Dong, Jing Li, Pei An, Long Zhao.