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Introduction: Paroxysmal kinesigenic dyskinesia (PKD) is a disorder that is characterised by brief episodes of involuntary movements triggered by other sudden movements., Patients and Methods: Here we describe the cases of nine patients from three unrelated families who had PKD in its familial idiopathic form., Results: The majority of the patients (77.7%) were males. The mean age at onset was 10.3 years. All the subjects presented sudden movements as factors that precipitated the crises, which lasted < 10 s in 88.8% of cases. Two thirds (66.6%) of the patients were treated with carbamazepine, phenytoin and valproic acid and all of them responded well. Spontaneous remission occurred in 62.5% of the patients over 20 years of age and in a further 25% there was a significant decrease in the number of crises., Conclusions: In our sample the proportion of patients who presented spontaneous remission was greater than in that reported in previous studies. As in other series, we found positive responses to antiepileptic drugs other than carbamazepine.

Familial paroxysmal kinesigenic dyskinesia (PKD) is a rare disorder featuring brief, dystonic or choreoathetotic attacks, typically triggered by sudden movements. Symptoms usually start in mid-childhood, although in several pedigrees infantile convulsions have been reported as the presenting sign. Previous linkage studies have identified two PKD loci on 16 p12.1-q21. We report here the clinical features of a Spanish kindred with autosomal dominant PKD, in which haplotype data are compatible with linkage to the pericentromeric region of chromosome 16 and exclude linkage to the locus for Paroxysmal Non Kinesigenic Dyskinesia (PNKD) on chromosome 2 q35. In this family, the conservative candidate region for the disease lies between markers D16S3145 and GATA140E03 on 16 p12.1-q21 and partially overlaps with both the Paroxysmal Kinesigenic Dyskinesia - Infantile Convulsions (PKD-IC) critical interval and the Episodic Kinesigenic Dyskinesia 2 (EKD2) locus. Unusual findings in our pedigree were early infantile onset of the dyskinesias in one patient and generalized seizures as adults in two, adding to previous observations of phenotypic overlap between epileptic and non-epileptic paroxysmal disorders. Further clinical and genetic studies are needed to elucidate whether PKD and PKD-IC are allelic disorders with age-dependent phenotypic expression.