A woman beat her 83-year-old mother round the head during an incident at their home, Lincoln Crown Court was told.
Elizabeth Day was “blind drunk” when she reacted after her mother failed to pass on a message to her.
David Webster, prosecuting, said that the mother, Kathleen Day, was reading in bed at the family home in Washingborough when her daughter carried out the attack.
Mr Webster told the court: “It seems her mother received a message that was meant to be passed on to her daughter.
“When she didn’t pass on the details that resulted in an argument.
“Her mother was in bed reading. Elizabeth Day started hitting her around the head. She describes herself as being beside herself with anger.
“As a result of that Kathleen Day was left with injuries including bruising.
“Elizabeth Day accepted at the time that she was blind drunk. She called the ambulance the next day in the cold light of sobriety.”
Elizabeth Day, 53, formerly of Leicester Close, Washingborough, but currently detained at Arnold Lodge Psychiatric Unit, Leicester, admitted a charge of assault occasioning actual bodily harm as a result of the incident on May 12, 2018.
She was ordered to be detained at Arnold Lodge under section 37 of the Mental Health Act and given a five year restraining order banning her from visiting the home of her mother.
The court was told that her mother and sister both support the fact that she needs treatment.
Karen Walton, for Day, said her client had never been in trouble before and suffers from mental illness, having been diagnosed as having either paranoid personality disorder or a delusional disorder.
Miss Walton said: “Following her arrest she spent a considerable time in prison but is now in the right place to get care for her mental health problems.
“She is utterly appalled at what she did to her mother. It is something she is deeply upset about and she is ashamed of her actions.”