The investigators perform neuropsychological tests and brain scintigraphy in 30 healthy subjects.

These results will be compared with data obtained out of episode in patients with Kleine-Levin syndrome (KLS).

The investigators want to determine if brain functional imaging and cognitive abnormalities persist during asymptomatic period in a large series of patients with KLS, and to find predictors of these abnormalities.

3 steps in the protocol :

• Brain ECD-SPECT (marking brain perfusion in relation to brain active/hypoactive area) superimposed on a template T1-weighted brain MRI.
• Extensive cognitive tests of executive functions, verbal memory and fluency , visuospatial ability and memory, reasoning abilities: spontaneous memory complaint, Stroop Color Word Test, Trail Making Test A and B, Direct and Reverse Digit Span Test, Letter and Semantic Fluency Test, Free and Cued Selective Reminding Test, Rey-Osterrieth Complex Figure, Mini-Mental test, Progressive matrice of Raven (PM-38)
• KLS-inventory and face to face interview of patients and parents by neurologist for patients. Modified KLS-inventory for healthy subjects.

Main outcome : Number of patients with persisting hypoperfused brain area (compared to controls), location of these area, number of patients with at least -1SD in one cognitive domain Correlation between KLS severity (disease course, number of episode, mean duration of episodes, time incapacitated, number of symptoms) and brain perfusion and cognitive abnormalities

Inclusion criteria :

• Subjects males and females with more than 18 y.o, age and sex-matched with patients with Kleine-Levin Syndrome
• with the same educational level and dominant hand than patients with Kleine-Levin Syndrome
• without any brain disease or sleep disease (Epworth score < 11/24) known.
• with social security
• french language
• for women : nonpregnant taking effective contraception

Exclusion criteria :

• Minor subjects
• adults under protection
• subjects with neurologic, psychiatric, somatic or sleep diseases and/or receiving a psychotropic medication interfering with the results.
• subjects with history of seizures or loss of consciousness
• subjects with excessive alcohol consumption (more than 3 doses /day)
• subjects without any social security
• subjects non fluent in french
• for women : no effective contraception or lactation period

Healthy subjects