A support worker at Calderstones hospital was attacked without warning by a 21-year-old patient.
Blackburn magistrates heard that Gemma Louise Hulme grabbed her victim by the hair and pulled her down before kneeing her about the head.
Calderstones support worker Miss Kathryn Watson was unable to activate her panic alarm and had to rely on another patient to run and get help.
When she appeared before rthe magistrates Hulme pleaded guilty to assaulting Miss Watson. She was ordered to pay her £150 compensation.
Miss Catherine Allan (prosecuting) said Miss Watson had clumps of hair pulled from her scalp and was also bitten on her arm during the incident.
“She genuinely feared for her life,” said Miss Allan.
“She has had trouble sleeping and has had nightmares since this incident.”
Miss Gemma Zakrzewski (defending) said Hulme had been in Calderstones since she was 18 years old.
“She can’t offer an explanation for her behaviour,” said Miss Zakrzewski.
“Prior to this incident they seem to have enjoyed a good relationship.”