The Outcome of Dopamine Dysregulation Syndrome in Parkinson's Disease: A Retrospective Postmortem Study.

INTRODUCTION: We have performed a retrospective analysis of the frequency and relation to treatment of dopamine dysregulation syndrome (DDS) using the Queen Square Brain Bank (QSBB) database.

METHODS: A search of the QSBB database for consecutive cases donated between 2005 and 2016 with a pathological diagnosis of Parkinson's disease was performed.

RESULTS: DDS was present in 8.8% of cases, was more prevalent in males, and was associated with younger age of onset, longer disease duration, and more dopa-induced dyskinesias. Treatment approaches for DDS included: reduction of levodopa, reduction/cessation of dopamine agonist (DA), and initiation of infusion therapies. DDS had completely resolved in just over half the patients. DA peak l-dopa equivalent daily dose (LEDD) was higher in patients who failed to achieve remission.

CONCLUSION: This is the first study to provide data on the course of DDS until death. Treatment strategies consisted mainly of reduction of dopaminergic treatment, and, despite the majority of patients showing some improvement, half remained symptomatic. Successful treatment was associated with a lower l-dopa dosage at death.