1. Division of Endocrinology, Department of Internal Medicine, Hospital Rafael Ángel Calderón Guardia, San José, Costa Rica
2. Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
3. Laboratory of Molecular Biology, National Children Hospital, San José, Costa Rica
4. Department of Pathology, Hospital Rafael Ángel Calderón Guardia, San José, Costa Rica