Paroxysmal kinesigenic dyskinesia is a rare disorder, and there are few reports of Asian patients with this condition. We reviewed the clinical features of all patients with idiopathic paroxysmal kinesigenic dyskinesia (PKD) seen at a major neurological centre in Malaysia. The charts of 11 patients with idiopathic PKD seen between 1995 and 2008 were reviewed retrospectively. The male:female ratio was 9:2. Ten patients were of Chinese ethnicity, and one was Malay. Three patients (from two families) had a family history of PKD. The involuntary movement was dystonia in 73% of patients. In one patient, attacks were precipitated by vestibular stimulation. One patient had generalized epilepsy. Another patient who did not have epilepsy demonstrated epileptiform discharges. Only slightly over one-quarter of patients had a positive family history. Males, and people of Chinese ancestry, seem to be affected more frequently by PKD in certain Asian populations.
Secondary paroxysmal dyskinesias (PxD) have been previously reported in patients with multiple sclerosis, lacunar infarcts, head trauma, metabolic disorders such as hyperglycaemia, hypocalcaemia, migraine and central nervous system (CNS) infections. The causative lesions typically involve the basal ganglia structures, medulla and rarely the spinal cord. We report two patients who presented with paroxysmal dyskinesias as the only manifestation of subcortical white-matter ischaemia. Patient 1 presented with 3-year history of paroxysmal kinesigenic dyskinesia (PKD) and patient 2 with 6-month history of paroxysmal nonkinesigenic dyskinesia (PNKD). All investigations, including CSF oligoclonal bands were negative, except for a brain MRI which showed multiple, non-enhancing subcortical white matter lacunar infarcts. Therefore, subcortical white matter ischaemia should also be included in the differential diagnosis of PxD.