May 20 (Reuters) - The U.S. Food and Drug Administration has allowed billionaire Elon Musk's Neuralink to implant its brain chip in a second person after the company disclosed earlier this month that tiny wires inside the brain of its first patient had pulled out of position, the Wall Street Journal reported on Monday. (Reporting by Mariam Sunny in Bengaluru; Editing by Krishna Chandra Eluri)