Open Trial of Lamotrigine in the Treatment of Self-Injurious Behavior in an Adolescent with Profound Mental Retardation

This single case reports an open trial of lamotrigine in the treatment of self-injurious behavior (SIB) and epilepsy in an 18-year-old female diagnosed with generalized seizure disorder, Stereotypic movement disorder, and compulsive SIB in the context of profound mental retardation. Animal models of SIB suggest that the glutamate neurotransmitter systems, involved in the generation of epileptic seizures, may also have a role in the pathophysiology of SIB. Data suggesting that lamotrigine may decrease glutamate release encouraged an empirical trial of lamotrigine for treatment of SIB. After 4 weeks of treatment of lamotrigine 200 mg daily, decreases in agitation and fearfulness were clinically observed, along with a 50% reduction in the frequency of SIB as measured by standardized scales. Good seizure control was maintained throughout the trial. No significant adverse effects were observed. Positive effects persisted at 1-year follow-up. Symptoms of Stereotypic movement disorder appeared unchanged. Because these findings are preliminary, no clinical recommendations for the treatment of SIB with lamotrigine can be made until controlled studies have been completed.