Warning: This video and article discuss elderly abuse.

A horrific case of patient abuse has been uncovered at a nursing home in Sydney. A hidden camera recorded a nurse there terrorising an 85-year-old who has dementia.

Dana Gray, 59, was working in Sydney's The Poplars nursing home when her colleague became suspicious of her behaviour and set up a hidden camera inside the elderly woman's room.

The abuse is difficult to watch. The footage shows the nursing home worker repeatedly slapping and hitting the patient, grabbing her hair to drag her head from left to right while her victim screams and sobs.

She then grabs the bathroom rubbish bag and uses it as a weapon to beat the woman, savagely battering her across the face.

In a final act of cruelty she leaves the dementia patient's bed raised so she can't sit down. The 85-year-old is left to stand traumatised for several hours.

Appearing in court this week, Magistrate Robyn Denes sentenced Gray to 17 months' imprisonment with a non-parole period of six months for inflicting "gratuitous cruelty" on the patient.

"It seemed to me that all your frustrations, all your anger was taken out on this lady," Ms Denes said.

"Even the act of leaving that bed raised... was heartless.

"As a coup de grace you hit her with the rubbish bag. The humiliation of that victim was complete."

Ms Denes said Gray had shown "very limited real remorse", and anyone with a parent or loved one in aged care would be deeply concerned by Gray's behaviour.

"The degree of violence used in this instance is extreme," the magistrate said. "What happened to [the victim] is everyone's worst nightmare."

The matter has been adjourned until September for a home detention assessment. Gray remains on bail.

Newshub.