RESUMEN
INTRODUCTION: ROHHAD syndrome (rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation) is a rare and complex disease, presenting in previously healthy children at the age of 2-4 years. Up to 40% of cases are associated with neural crest tumours. DEVELOPMENT: We present the case of a 2-year-old girl with symptoms of rapidly progressing obesity, who a few months later developed hypothalamic dysfunction with severe electrolyte imbalance, behaviour disorder, hypoventilation, and severe autonomic dysregulation, among other symptoms. Although the pathophysiology of this syndrome remains unclear, an autoimmune hypothesis has been proposed for ROHHAD. Therefore, after obtaining a limited response to intravenous immunoglobulins, we decided to test the response to a high dose cyclophosphamide (low dose was not effective either). Unfortunately our patient experienced many severe complications (among them central pontine myelinolysis, from which the patient recovered, and failure to wean from the ventilator requiring tracheostomy and long term ventilation) that required a prolonged ICU stay. Although her behaviour improved, our patient unfortunately died suddenly at home at the age of 5 due to respiratory pathology. CONCLUSIONS: ROHHAD syndrome is a rare and little-known disease which requires a multidisciplinary approach because it involves complex symptoms and multiple organ system involvement. Alveolar hypoventilation should be identified early and appropriate treatment should be started promptly for the best possible outcome. Immunomodulatory treatment with immunoglobulins, cyclophosphamide, or rituximab has previously resulted in symptom improvement in some cases. Because of the low incidence of the syndrome, multi-centre studies must be carried out in order to gather more accurate information about ROHHAD pathophysiology and design an appropriate therapeutic approach.