[Clinical presentation of Kleine-Levin syndrome]

Objective: To analyze the clinical features of Kleine-Levin syndrome (KLS) patients. Methods: Clinical data of 44 patients with KLS of the Sleep Center of Peking University People's Hospital from January 2002 to July 2013 were systematically reviewed. The predisposing factors and clinical presentations were summarized, and compared with the data from a Western KLS study with a large subjects number. Nocturnal polysomnography (PSG) and multiple sleep latency test (MSLT) were conducted during relapse and remission period, respectively. HLA-DQB1*0602 gene were screened and analyzed. Results: Among the 44 patients, 28(63.6%) were men and 16(36.4%) were women, with a mean age of (18.3±8.9) years old. Most patients developed the symptoms during adolescence. Infection or fever was the most common trigger for episode. The main clinical presentations were 44(100.0%) hypersomnia, 31(70.5%) forgetfulness, 26(59.1%) decreased appetites, 24(54.5%) juvenile behavior, 18(40.9%) depression, etc. Compared with the Western study, it showed that our patients had decreased instead of increased appetite. The PSG testing did not have remarkable findings. MSLT showed mean sleep latency was significantly shorter during relapse than during remission [(10.4±5.4) vs (15.3±3.4) min, P=0.009]. HLA-DQB1*0602 was positive in 12 of 40(30.0%) patients, which was similar to the data in the Chinese population. Conclusions: KLS has various clinical characteristics. The presentation of appetite may be different between Chinese and western KLS patients.