An English woman went to sleep with a terrible migraine and woke up speaking in a French accent. She has been diagnosed with a rare effect called foreign accent syndrome, which can occur as a result of brain injury, severe migraine, or stroke. Experts say that the afflicted do not actually speak with a foreign accent.
Instead of speaking in some foreign dialect, their brain has been injured in a manner that affects their speech and they sound as if they might be speaking in a certain accent. The injury to the brain effects vocalisation and their speech is changed to a degree where they might sound as if they were French, Chinese, Indian or whatever language the listener is apt to interpret.
So, although Kay Russell, who used to have a southern English accent, now sounds as if she has a French accent, she does not. Changing the blood flow to the brain, as in the event of a stroke, injury, or even very severe migraine, will greatly impact the speech capabilities of the brain. Experts feel that Ms. Russell may have been lucky to wake up with the ability to speak at all, let alone sounding strangely unlike herself. While her voice may carry certain qualities of sound that seem French, she is unlikely to have picked up any of the regional nuances of that language.