in april 2009, mørk experienced an infection of the central nervous system, presumably caused by a tick bite he received in the united states in 2006, with subsequent encephalitis, and paralysis in the shoulder muscles of the left arm. in the autumn of 2009, he expressed concern that he might never be able to perform again. after 18 months away from concert activity, during which time he was awarded the 2010 sibelius prize, mørk resumed his career.