DSI telemetry devices have been used to record deep brain EEG with some modifications to the EEG lead wires. This requires exposing a portion of the EEG wire and attaching it to the deep brain electrode prior to implanting. Please see the additional resources below for more information on this procedure as well as a video outlining one method of attaching the electrode and telemetry lead wires.

Additional Resources:

https://www.jove.com/video/54216/non-restraining-eeg-radiotelemetry-epidural-deep-intracerebral

https://review.jove.com/pdf-materials/54216/jove-materials-54216-non-restraining-eeg-radiotelemetry-epidural-deep-intracerebral

https://insidescientific.com/podcast/expertanswers-marco-weiergraber-and-jennifer-teske-on-measuring-sleep-with-eeg/