Hyperkinetic Movement Disorder Emergencies.

A movement disorder emergency has been defined by Fahn and Frucht as "any neurological disorder evolving acutely or subacutely, in which the clinical presentation is dominated by a primary movement disorder, and in which failure to accurately diagnose and manage the patient may result in significant morbidity or even mortality." In this review, we discuss the most common situations in which hyperkinetic movement disorders, including chorea, ballism, dystonia, myoclonus, tics, as well as psychogenic disorders, can present as emergencies. Some acute hyperkinetic issues that can complicate Parkinson's disease and parkinsonism, such as the rare dyskinesia-hyperpyrexia syndrome, will be also covered. The phenomenology and natural history of medication-induced dystonic reaction, a common form of acute secondary dystonia frequently leading to emergency department consultations, are discussed in detail. Despite the acute nature, most of these conditions can result in a good outcome. Rare but serious disorders such as status dystonicus or malignant Gilles de la Tourette syndrome may lead to substantial morbidity and mortality. Thus, we emphasize the need to develop means for more accurate and prompt recognition and treatment of these syndromes.