EEG and VNS

I work for a neurologist who reprogrammed a patients VNS. Then he did an EEG on the same day as the reprogramming to see if the patient had epileptic seizures. I thought if the patient had a VNS it is because they have epilepsy or epileptic seizures. I am just making sure that it is correct to do an EEG no someone who has a VNS?

Thanks for your help.

Caroline

EEG and VNS