The doctor diagnosed the cause of the headaches after going through the actor's medical history. The pain in the neck and the headaches were caused by the expressions and posture of Rizwan Khan, SRK's character in MNIK. Rizwan, who has Asperger's Syndrome, has a way of jutting his neck out at a particular angle and wears an expression which has his eyebrows raised in every scene. As he would shoot for hours, he'd get severe migraines. Today, he's been seeing a physiotherapist to get rid of the pain in his neck.
Director Karan Johar admits, "I guess that's one of the hazards when you play your role so intensely. Shahrukh's character Rizwan had to arch his eyebrows and focus his eyes on a certain place before every take. Halfway through the shooting of the film, Shah Rukh developed severe headaches as result of all the pressure it would put on his head so he had to see a neurosurgeon for that. We were worried... Shahrukh has never had this problem before"
Karan goes on to say that those afflicted with Asperger's develop certain physical personality traits, something SRK had intensely studied while shooting for MNIK. "In Asperger's, each trait is uniquely different from each person. Their way of talking to people, body language, way of holding their heads -- are different from one another. It's a high-functional autism where a person leads a completely regular life but has certain traits that sets him apart. Like apart from fear of noises and new people and places, Rizwan is also scared of the colour yellow and is emotionally disconnected to it."