Cataplexy is characterized by muscle paralysis during cognitive awareness. Until now, researchers have not understood this condition well. Now research has shown that the neuro-degeneration of the brain cells that synthesize the chemical hypocretin causes the noradrenaline system to malfunction. When the norandrenaline system stops working properly, it fails to keep the motor and cognitive systems coupled. This results in cataplexy -- the muscles fall asleep but the brain stays awake.