Britney Spears inadvertently upset the family of a birthday girl during her recent stay in hospital when medical staff insisted on imposing tough laws. An angry mum kicked the door to Spears' private room after staff at Cedars Sinai Medical Center refused to let her take a birthday cake to her daughter, a fellow patient. Spears was committed to the hospital under the pseudonym Barbara Jean after an apparent breakdown at her home. U.S. publication In Touch Weekly reports the troubled pop star spent her hospital stay in the third floor Psych Unit at Cedars Sinai, where she was medicated and evaluated before being released. But it was when she was recovering from injuries, caused during her bizarre topless stand-off with police in the locked bathroom of her home, on the eighth floor of the hospital that she started causing trouble without meaning to. Insiders say that Britney's presence caused "mini-riots" throughout the facility. The publication reports one patient's mother wanted to have a small party for her daughter, but was told she wouldn't be allowed to bring a cake into the ward. A source says, "The mom screamed, `If Britney brought the cake you'd let her, before kicking the door to Britney's room, which caused Britney to yell back at the woman." Britney then declined an offer to join other patients in wishing the girl a happy birthday, even though the gathering was in the next room.