Turkish Airlines Press Release
According to the Turkish press, the public relations department of the Turkish Airlines released the following note:
"The Captain had his medical check at a hospital authorised by the [General Directorate of ] Civil Aviation in November 2012, and certified fit to fly. None of the previous medical checks indicated a symptom associated with epilepsy. The investigation has been going on and we cannot make any further comments during that process on the personal medical condition of our Captain."
Couldn't find the original text, but it is quite common in Turkish aviation industry to pass the message to selected members of the press, in stead of releasing information to public. The comments of the press indicate that some captains are required to get their medical checks every six month while other are required to do so every year. No mention of why the difference.
Nothing released by the Civil Aviation authority yet.
As usual they would let it pass and forgotten by and by...