Division, Child Neurology Children's Medical Center 62 Gharib St., End of Keshavarz Blvd., Tehran, Iran. Tel. +9821-66929234, +9821-88953001 Fax. +9821-66404377 Private Clinic 2, Najm Alley, Felestin Ave, Tehran, Iran. Tel. +9821-66461891 Fax. +9821-66491883 Emails; mohamadi@tums.ac.ir, mahmoh365@yahoo.com