Brain Pacemaker

Deep brain stimulation (DBS) is one of a group of treatments involving surgical implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain.

It is used for advanced Parkinson's disease resistant to medical treatments. Other indications include severe essential tremor, primary dystonia and epilepsy.

It is true that Parkinson's patients are now increasingly receiving DBS devices. So, when you see a scar at the left/right pectoral region in a parkinson patient, please think of :
1- DBS device.
2- Cardiac pacemaker for associated arrhythmia(coincidental findings).

source: passpaces forum - Parkinson's ds tips