Lamotrigine monotherapy for paroxysmal kinesigenic dyskinesia in children

• LTG monotherapy is effective for PKD in children.
• LTG monotherapy for PKD in children is well tolerated.
• Therapeutic dosage of LTG is very low for PKD in children.
• It seems the effective dosage of LTG has little correlation with age or weight.

PurposeTo evaluate the efficacy and tolerability of lamotrigine monotherapy in children with paroxysmal kinesigenic dyskinesia.MethodA sample of eighteen children aged between 2 years old and 13 years old who fulfilled the diagnostic criteria from January 2008 to December 2014 was enrolled, they received video electroencephalography, brain image scans and proline-rich transmembrane protein 2 genetic tests. Children with known or suspected diseases which would cause secondary paroxysmal kinesigenic dyskinesia were excluded. The initial dosage of lamotrigine was 6.25 mg, and it was gradually increased every week until attacks were controlled. Patients entered the maintenance dose phase upon reaching the effective dosage, and by being attack free at two consecutive outpatient visits. They were followed up for a couple of years until December 2014.ResultsBy the end of the 4th week, the attack-free rate reached 100% among all the patients. During the maintenance dose phase, 16 patients remained attack free, 2 patients received additional drug due to attack relapses when they entered puberty. Three patients had relapses because of non-compliance to the therapy, but they became attack free as soon as they re-started the medicine. The mean daily dosage was 26.4 mg (range 6.25–50). Definite adverse effect related to the drug was not reported in follow up.ConclusionLTG monotherapy is effective and well tolerated for PKD in children.