Withdrawal of levodopa and other risk factors for malignant syndrome in Parkinson's disease.

A symptom complex identical to neuroleptic malignant syndrome (MS) is known to develop in patients with idiopathic Parkinson's disease (PD) or other forms of parkinsonism on long-term treatment with anti-parkinsonian drugs. In order to clarify the risk factors for parkinsonian MS, the authors retrospectively reviewed charts of consecutive inpatients with PD in the neurological departments at the three hospitals and found 16 episodes of parkinsonian MS in 14 patients. A survey of health status preceding MS disclosed that deterioration of parkinsonian symptoms alone may induce MS, while association of major risk factors, i.e. rapid discontinuation of anti-parkinsonian drugs, dehydration or infection may precipitate or exacerbate MS. Cerebral vascular disorders, mechanical brain injury or physiological stress could be other risk factors leading to MS.