Lower dopamine transporter density in an asymptomatic patient with Kleine-Levin syndrome.

BACKGROUND: Kleine-Levin syndrome (KLS) is a rare disorder whose pathophysiological mechanisms remain unknown. PATIENTS AND METHODS: To investigate dopamine abnormalities in KLS, a [99mTc]-TRODAT-1 single photon emission computerized tomography (SPECT) was performed in a patient with KLS during the asymptomatic period and compared with three matched healthy controls. RESULTS: The patient had 14% lower striatal dopamine transporter binding potential (DAT-BP) compared to the mean DAT-BP of three healthy controls. CONCLUSION: This study provides in vivo evidence for abnormalities in the DAT-BP, suggesting an involvement of the dopaminergic system in the pathophysiology of KLS.