Sheffield Crown Court was told that officers forced their way into their shared flat after Shaw barricaded himself following the violent attack on January 1 this year.
The court heard how the victim was found on the floor with a swollen face and eye, and was left with blood all over her face and clothes.
The walls and carpets were also covered in blood, the court was told.
Prosecutor Richard Thyne said Shaw’s mother suffered eye socket fractures possibly due to punches, bruising to her face and forearms, facial burns, chest pain, and bleeding to the brain.
At the time of his arrest, Shaw was brandishing a hammer and was restrained using a stun-gun and handcuffs by officers.
The court was told there was no evidence the hammer Shaw was used in the attack, but his mother had a cut to her head consistent with the impact from a kettle.
Shaw, of Sheffield, pleaded guilty to causing grievous bodily harm with intent and was sentenced to eight years in jail.
Defending, Ian Goldsack said Shaw’s mental health had been deteriorating from substance misuse after he stopped smoking cannabis suddenly.
He replaced the addiction with alcohol and cocaine, which was making him paranoid.
Shaw’s mother told police he had become difficult to live with and was hearing voices and talking about poisonous gases being pumped into the flat.
Shaw has one previous conviction for common assault from 2002.
Judge Richardson said Shaw had attacked his mother in a ‘particularly brutal fashion’ after consuming ‘a cocktail’ of cocaine and alcohol.