Follow-Up Studies On4Cases Of Idiopathic Paroxysmal Kinesigenic Dyskinesia

BackgroundParoxysmal kinesigenic dyskinesia (PKD) is the most common type of Paroxysmal dyskinesias (PDs/PxD). PKD episodes are triggered by sudden voluntary movments, and the attacks are typically brief, lasting seconds. The abnormal movement disorder is mainly manifested by dystonic, chorea, atheotosis and ballism. PKD can be primary/idiopathic, or secondary to other disorders such as demyelinating disease, cerebrovascular diseases and metabolic conditions. Most cases of PKD are primary and probably of genetic origin. Among the primary forms, more than half of PKD patients have family history of a similar disorder with an autosomal dominant inheritance. EEGs of some patients may show ictal or interictal abnormalities, but the pathophysiology of PKD is still unclear and its relationship with epilepsy has remained unresolved. PKD is a rare condition, easily to be misdiagnosed. In2004, Bruno and coworkers proposed a new diagnostic criteria of PKD based on the clinical characteristics. Some antiepileptic drugs are effective for the disease. In adults, a low dosage may be effective in controlling the episodes, accordingly the drug adverse events are slight. Further study on the relationship between the dosage of drug and the severity of episodes is needed.Objective4cases of idiopathic PKD were reported, including the clinical manifestations, electroencephalography (EEG), drug therapies and the follow-up studies. Combining with the literature review, the clinical characteristics, diagnosis and treatment of PKD, as so as the genetic background, pathogenesis and prognosis of the PKD were discussed.Methods4patients of our hospital who satisfied the diagnostic criteria for PKD of Bruno were collected since2012. The clinical menifestations, EEGs, the effect and side effect of drugs were analyzed.ResultsThere are four patients in our study,3males and1female, male to female ratio was3:1. The onset age on average is14.25y. All of them had no family history of similar disorder, no history of infantile afebrile convulsion or epilepsy. Clinical manifestation exhibited dystonia induced by sudden movements, involving unilateral or bilateral extremities and the face. Attack frequency ranges from2-5per day to as few as1-2per week. Most patients suffered2-5attacks per day. Attacks lasted less than half a minute each time. The attacks do not involve a loss of consciousness. Three of the patients had abnormal EEGs, characterized by diffuse or focal epilepsy discharge. Lamotrigine, carbamazepine and topiramate were given to patients respectively, except one patient with topiramate treatment reperted side effect, the others were responded well to the antiepileptic drugs. The clinical symptoms of all patients were completely controlled.ConclusionsPKD is a benign movement disorders, some patients exhibit ictal or interictal abnormal EEGs. PKD is responded well to low-dose anticonvulsants. People usually benefit from anticonvulsants in a few days. The disease should be differentiated from epilepsy so as to avoid excessive use of antiepileptic drugs and unwanted side effects. The prognosis of PKD is relative benign.