Emergencies in parkinsonism: akinetic crisis, life-threatening dyskinesias, and polyneuropathy during L-Dopa gel treatment.

This article reviews literature on three emergencies in Parkinson's disease (PD): Akinetic crisis, severe dyskinesias or life-threatening dyskinesias, and polyneuropathy during duodenal L-Dopa gel infusion treatment. Akinetic crisis is also known as Parkinsonian hyperpyrexia, Neuroleptic-like malignant syndrome, Acute akinesia, and Malignant syndrome in parkinsonism. It appears in 0.3% of PD patients/year, and is characterized in the most severe cases by total akinesia with dysphagia, hyperthermia, dysautonomia, increment of muscle enzymes and alterations of mental status, but it may also appear in less severe forms ("forme frusta"). At difference with the continuum of motor hypokinesias observed in PD it is characterized by transient (in cases with favorable outcome) unresponsiveness to rescue drugs. Life-supporting measures are mandatory in patients affected by this emergency. Severe dyskinesia, or life-threatening dyskinesia, is due to increased dopaminergic stimulation (either by the patient or by the prescriber): when it appears the level of dopaminomimetic stimulation should be reduced. Polyneuropathy during duodenal L-Dopa gel infusion is a recently described complication, attributed to the onset of Guillain-Barré syndromes. However, hemapheresis was not effective in some reported cases, and recent evidence suggests that Vitamin B12 deficiency or direct high-dose chronic L-Dopa toxicity might play a role in its origin.