Brief Communication Childhood paroxysmal kinesigenic dyskinesia: Report of seven cases with onset at an early age Zhongzeng Li a, * , Robert P. Turner a,b,c , Gigi Smith a a Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA b Department of Pediatrics, Bioinformatics and Epidemiology, Medical University of South Carolina, Charleston, SC 29425, USA c Department of Biostatistics, Bioinformatics and Epidemiology, Medical University of South Carolina, Charleston, SC 29425, USA Received 6 December 2004; revised 24 January 2005; accepted 26 January 2005 Abstract We report on seven children who developed abnormal involuntary movements as early as 1 1 2 years after unremarkable term births. The paroxysmal episodes of abnormal movements were typically precipitated by sudden, voluntary movements, or a startle. The clinical features in each case were consistent with the diagnosis of paroxysmal kinesigenic dyskinesia (PKD). The episodes of abnormal movements are described. EEG was obtained in all cases, and video/electroencephalography (VEEG) monitoring was per- formed to exclude the possibility of epilepsy in six patients. VEEG studies revealed multiple events consistent with PKD; no ictal epileptiform discharges were recorded. The apparent benign nature of the disorder, as well as treatment options with antiepileptic drugs, was discussed with the parents, and most chose no pharmacologic treatment. We discuss clinical characteristics of PKD, treatment with anticonvulsant therapy, and recent insights into its possible pathophysiology. Ó 2005 Elsevier Inc. All rights reserved. Keywords: Antiepileptic drug; Movement disorder; Paroxysmal kinesigenic dyskinesia; Paroxysmal kinesigenic choreoathetosis; Regional cerebral blood flow; Video/electroencephalography 1. Introduction Paroxysmal kinesigenic dyskinesia (PKD), also called paroxysmal kinesigenic choreoathetosis (PKC), is an uncommon movement disorder characterized by brief, frequent episodes of abnormal involuntary movements that are precipitated by sudden voluntary movement of the body, primarily face, arms, and legs, especially after a period of rest [1–5]. Though rare cases of paroxysmal episodes of abnormal movements with preserved con- sciousness may be secondary to a lesion in the supplemen- tary motor area [6,7], this is not present in children diagnosed with PKD. Electroencephalography (EEG) or video/EEG (VEEG) monitoring is often required to exclude epilepsy, though the clinical manifestations of PKD are stereotypic and uniquely different from seizures. Etiology in a majority of children with PKD is apparently idiopathic, and age of onset is usually in later childhood or adolescence [1,3–5,8]. We report seven cases of early- onset (<5 years) childhood PKD seen in our pediatric epi- lepsy program. Review of home videotape recordings (two cases) and VEEG monitoring (six cases) suggested the clinical diagnosis from characteristics of abnormal movements and the absence of scalp EEG changes. The clinical data on each case are summarized in Table 1. 2. Case reports 2.1. Case 1 (K.G.) A3 1 2 -year-old female was referred for evaluation of abnormal involuntary movements, present over the 1525-5050/$ - see front matter Ó 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.yebeh.2005.01.011 * Corresponding author. Fax: +1 843 792 0029. E-mail address: LiZhong@musc.edu (Z. Li). www.elsevier.com/locate/yebeh Epilepsy & Behavior 6 (2005) 435–439