RESUMEN
BACKGROUND: Locked-in syndrome represents the most severe form of central pontine myelinolysis and varies in presentation from asymptomatic to fully developed locked-in-syndrome characterized by the combination of quadriplegia, loss of the ability to communicate except through the use of the eyes, and an inability to follow commands. METHODS: We report a 10-year-old boy who developed a severe case of locked-in syndrome after heart transplantation. RESULTS: Patient had a spontaneous recovery, treated with supportive treatment and the improvement was detected with cessation of calcineurin inhibitor therapy by substituting with an mTOR inhibitor (sirolimus). No cases of locked-in syndrome post-heart transplant in pediatrics cases have been documented in the literature. CONCLUSION: Physicians should recognize a rapid progression of central pontine myelinolysis and locked-in syndrome in the context of heart transplant and although several factors likely contributed to this outcome, adjustment of immunosuppression including by substituting tacrolimus with sirolimus could be effective.