Paroxysmal Kinesigenic Dyskinesia: when to Diagnose?

Case presentation: We report a case of a previously healthy 14-years-old teenager who at age of 11, initiated involuntary movements that affected both arms and legs with an initial frequency of twice a day. Despite being involuntary, the teenager was able to control the movements. After three months, they intensified their frequency, occurring countless times a day, throughout the body, becoming uncontrollable. She reported that she was able to sense when they would occur and have never lost consciousness during these movements. The episodes were triggered by everyday activities like getting out of bed or a chair after a period of physical rest, leading to previous erroneous diagnoses of psychological and psychiatric conditions. There was no information regarding the usage of previous medications or previous diseases. There was no learning commitment or cognitive dysfunction. After some evaluations, she was referred to a Pediatrics Neurology service where Paroxysmal Kinesigenic Dyskinesia was diagnosed, when the introduction of Carbamazepine was indicated, with total control of involuntary movements.

Discussion: Paroxysmal Kinesigenic Dyskinesia is a rare disease, with a prevalence of 1/150,000 cases, characterized by abnormal involuntary movements that are precipitated by a sudden movement or startle, without altered consciousness, and repeated several times a day. Evaluating the frequency of types of movements, the most common observed is dystonia (57%), followed by chorea in 6% of patients and ballismus in 1%. Most cases are idiopathic, but certain patients have a family history, which is typically inherited by an autosomal dominant pattern. The first-line treatment is Carbamazepine, but alternative treatments include Lamotrigine, Levetiracetam, Oxcarbazepine, Valproate, Topiramate, and benzodiazepines. Diagnosis is based primarily on history and clinical observation, confirmed by normal images, Electroencephalogram and laboratory test results. Paroxysmal Non-Kinesigenic Dyskinesia and Epilepsy are the main differential diagnosis to be considered.

Final comments: The case refers to Paroxysmal Kinesigenic Dyskinesia, concerning a female teenager with several involuntary movements per day, triggered by movement and routine actions, with no cognitive or learning impairment. None of the events occurred during sleep nor caused altered consciousness. The age of onset was typical, and all complementary investigation was normal. The introduction of Carbamazepine offered a complete resolution of events.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
18 September 2023