Reduction of self-mutilating behavior and improved oromotor function in a patient with Lesch-Nyhan syndrome following botulinum toxin injection: A case report.

Lesch-Nyhan syndrome is a genetic metabolic disorder often involving dystonia and self-mutilating behavior. This case report describes a 13-year-old boy with Lesch-Nyhan syndrome and self-mutilating behavior who received botulinum toxin injections to his bilateral masseter muscles after failing multiple other treatments. Following injections, the patient had reduction in self-biting, along with improvements in speech, mastication and feeding observed in speech therapy. Botulinum toxin injections to the masseters may help to improve oromotor function and reduce self-mutilating behaviors in children with Lesch-Nyhan syndrome who have failed more conservative treatments, providing opportunity for improved functional status and patient safety. Further investigation is indicated to establish optimal dosing. Additionally, the mechanism for the reduction of self-mutilating behavior is unclear and justifies additional investigation.