Can brain damage make you brilliant?

Savant for a Day: "[The Medtronic] also produced, they noted, strange and unexpected effects on patients' mental functions: one minute they would lose the ability to speak, another minute they would speak easily but would make odd linguistic errors and so on. A number of researchers started to look into the possibilities, but one in particular intrigued Snyder: that people undergoing transcranial magnetic stimulation, or TMS, could suddenly exhibit savant intelligence -- those isolated pockets of geniuslike mental ability that most often appear in autistic people."