Lamotrigine-induced tic disorder: Report of five pediatric cases

Purpose: To describe the clinical spectrum of lamotrigine (LTG)-induced tie s (an uncommon side effect) in children. Methods: Retrospective analysis of patients from our hospital-based practic e who developed ties while on LTG. Data obtained from medical records, inte rviews with parents, video-EEGs, and homemade videotapes. Results: Three males and two females (range, 2.5-12 years; mean, 6.9 years) developed a movement disorder within the first 10 months of therapy (maint enance doses, 4-17 mg/kg/day). Four patients exhibited simple motor ties; o ne patient experienced mostly vocal (i.e., gasping sounds) ties. Laryngosco pic evaluation of one 2.5-year-old with repetitive gasping sounds was norma l. In three cases, ties resolved completely within 1 month of drug cessatio n; ties recurred in two of these patients after reintroduction of LTG. A fo urth patient experienced gradual improvement after stopping LTG over 4 mont hs; the fifth patient's simple motor ties improved spontaneously with a red uction in medication. None of the patients had clinical features of a neuro degenerative disorder, and none met diagnostic criteria for Tourette syndro me. Two patients, however, had a diagnosis of acquired epileptic aphasia sy ndrome, and one patient had nonprogressive expressive and receptive languag e dysfunction. A fourth patient had global static encephalopathy, and the f ifth patient had only attentional problems. In all patients, ties were not associated with ictal EEG changes. Conclusions: LTG may infrequently induce simple motor ties, vocal ties, or both. Patients with severe language dysfunction may be particularly suscept ible to this uncommon side effect. Further studies are necessary to clarify the population at risk.