The procedure that Dr Loboto received, I do believe was never specified to specifically be a lobotomy, just a procedure of the brain performed with an ice pick (presumably through the eye). The word lobotomy is never used and it can be inferred, but it’s entirely possible for it to have been something else, maybe even something related to where psychic powers are in the brain.
Having said that it may not have been a lobotomy itself, given the timeline of popularity of lobotomies as a reference point, and assuming the game takes place in the 80′s-90′s mishmash Tim Schafer envisioned, Loboto would have been lobotomized around the same time as the fall of Grulovia, in the 60′s as lobotomies were starting to become a hot button controversial issue. That would also place him around the age of Augustus and, assuming his kid is one of the campers, having had his kid at around the same time as Augustus and Donatella had Raz.