Dropped head syndrome with necrotizing myopathy: A drug class effect confirmed by 3 repeated exposures to non ergolinic dopamine agonists, due to l-Dopa phobia

BackgroundDropped head syndrome (DHS) or antecollis is a common complication in multiple system atrophy and a rare complication in l-Dopa responsive Parkinson's disease (PD). Few reports described DHS as a side effect of dopamine agonists (DAs) treatment in PD, mostly in Asian patients.Case reportWe report a single case of DHS in a 56 year-old Caucasian male patient affected by PD. Insistent and repeated DA treatment with pramipexole, ropinirole and rotigotine was due to l-Dopa phobia and DA withdrawal syndrome. Each DA treatment was accompanied by DHS recurrence with muscle enzyme increment.ResultsThe cause of DHS was identified by muscle biopsy as a necrotizing myopathy. Repeated administration of different DAs, inducing recurrence of DHS shows that DHS was due to a drug class effect of non ergolinic dopamine agonists.ConclusionThe exposure to three different non ergolinic DA induced DHS in this patients, suggesting a role of DA receptor sensitivity in the pathogenesis of DHS. Our case report also calls attention to a possible rare side effect of non ergolinic dopamine agonists go along with two other complications of PD treatments, l-Dopa phobia and dopamine agonist withdrawal syndrome, which prompted the repeated exposures.