Subthalamic deep brain stimulation masking possible malignant syndrome in Parkinson disease

Subthalamic (STN) deep brain stimulation (DBS) can improve all cardinal symptoms and signs of Parkinson disease (PD)1 but can have side effects.1–3⇓⇓ Patients with PD can have a malignant syndrome that in most cases is related to the sudden withdrawal of antiparkinsonian drugs.4 Its treatment depends on early diagnosis. When confounding factors exist, malignant syndrome in PD represents a diagnostic challenge. We report a patient with signs suggesting a malignant syndrome in which diagnosis was delayed because STN DBS produced partial benefit to the parkinsonism. A 58-year-old woman first experienced PD symptoms in 1984. Selegiline was prescribed, and levodopa was added 1 year later. In 1988, “wearing off” with foot dystonia appeared, and bromocriptine was started. She progressively deteriorated in spite of treatment modifications. In February 2003, she experienced unpredictable motor fluctuations, diphasic dyskinesias with stereotyped leg and trunk …