PINK1 and Mental deterioration: Carriers of the SNCA mutation are prone to developing cognitive decline, autonomic dysfunction, speech problems, and behavioral changes, which may affect the overall outcome of STN DBS.58 Carriers of the PINK1 mutation, on the other hand, usually manifest a slow progression of nonmotor symptoms,59 which suggests that this particular subtype of Parkinson disease may be a good candidate for STN DBS to address motor complications.