Twenty-one people were charged Tuesday after the Georgia Bureau of Investigation said it found widespread abuse of patients at a specialized care facility northeast of Atlanta. The bureau said its review had found that employees at Alzheimer’s Care of Commerce had struck patients, delayed changing diapers and used bedsheets as restraining devices. The inquiry also uncovered that people with felony convictions were involved in patient care, a violation of state regulations. The authorities filed more than 70 charges against current and former facility employees. The center’s owner, Donna Wright, was among those charged.