Improvement of epilepsy with lacosamide in a patient with ring chromosome 20 syndrome

Background Ring chromosome 20 syndrome is a rare chromosomal disorder characterized by refractory seizure, mental retardation, and behavioral problems. Although there are reports of the effective treatment of patients with antiepileptic drugs (AEDs), no study has reported the effects of lacosamide(LCM) in children with this syndrome. We report a 7-year-old boy with this syndrome whose refractory and behavioral abnormalities have been remarkably improved by treatment with LCM. Case presentation The patient was a 7-year-old boy with no medical or family history of epilepsy. He developed epilepsy with cessation of movement and derivation of the eyes followed by hyperkinetic seizures that made him squeak strangely and cling to his parents. The seizures lasted for less than a minute and were frequent (they occurred more than 30 times a day), particularly at night. Behavioral abnormalities such as hyperactivity also presented. Brain magnetic resonance imaging revealed no structural abnormalities, but an interictal electroencephalogram (EEG) indicated spikes and waves in the frontal lobe dominantly, and ictal single-photon emission computed tomography (SPECT) revealed a blood flow increase in the bilateral orbital frontal area in comparison to interictal SPECT. After chromosome examination, we diagnosed the patient with ring chromosome 20 syndrome (4/30 mosaic). Carbamazepine was ineffective, and seizures were exacerbated with levetiracetam (LEV). LCM was added to the treatment regimen with valproic acid (VPA) and lamotrigine (LTG); consequently, the seizures disappeared, and EEG results also improved. The patient’s behavioral disorders, such as hyperactivity, were improved, and he was able to return to elementary school. Conclusion Although VPA and LTG are generally effective for the treatment of ring chromosome 20 syndrome, they do not completely suppress seizures. LCM can be considered an effective option for seizure control in patients with this syndrome.