Treatment of paroxysmal dyskinesias in children.

Paroxysmal dyskinesia represents a group of uncommon movement disorders that are characterized by episodes of abnormal movements arising from a baseline of normal or nearly normal movement. Recent advances in the genetics of these disorders have helped provide some unification of classification schemes and better understanding. However, the approach to treatment continues to be based on the phenotype more than the genotype. The treatment approach is primarily based on the factors that precipitate the episodes of abnormal movements. For paroxysmal kinesigenic dyskinesia (PKD) in which the spells are triggered by sudden movement, treatment with anticonvulsants that target voltage-sensitive sodium channels (e.g., carbamazepine or phenytoin) is highly effective. For paroxysmal nonkinesigenic dyskinesia (PNKD), treatment with benzodiazepines is effective in many patients. PNKD episodes are often precipitated by caffeine, ethanol, or sleep deprivation, and lifestyle modifications are often helpful. Paroxysmal exertion-induced dyskinesia (PED) is less likely to respond to medications, but the ketogenic diet or modified Atkins diet may provide benefit. As more knowledge is gained about the underlying biology of these disorders, additional treatments may emerge.