My strange brain. Part 4.

The last in a four-part series which looks at the lives of people with unusual neurological conditions. This part features people who are dominated by their desires and compulsions following sudden brain injuries. Wife and mother Heather has developed a sex drive she can't control (known as hyper-sexuality) following a massive brain haemorrhage; in the last 3 years she has had inappropriate relationships with over 50 men and her marriage is crumbling. They visit compulsion specialist, Alice Flaherty, in Boston; Flaherty herself has suffered from compulsive behaviour. Previously a successful chiropractor and family man, John had surgery to correct a hearing problem but the surgery went wrong and he suffered an enormous stroke which left him in a coma. On waking his character was profoundly changed and he has since become a compulsive artist, suffering from a condition known as sudden artistic output. This is an extremely rare condition but Liverpudlian Tommy also suffers from it - John travels to England to meet Tommy and they discuss their experiences further. Orthopaedic surgeon Tony was struck by lightning in 1993 and, despite having never played an instrument before, he become obsessed with piano music, both playing it and listening to it. He has written a sonata, the Lightning Sonata, which we see him perform on stage for the first time.