A quiet night's sleep is not an option for Derek Rogers or his wife - because he turns from a mild-mannered "Dr Jekyll" by day to a "Mr Hyde" by night.
Derek can lash out in his sleep
Mr Rogers, 70, from Bedford, has a rare sleep disorder which causes him to become violent when he sleep-walks.
He has destroyed furniture, attacked his wife and injured himself during the night - but remembers nothing.
Doctors at Papworth Hospital have found a drug which has successfully treated Mr Rogers' "unique" condition.
Since he developed the condition in 1998, Mr Rogers has visited casualty up to three times a week.
He has broken his nose, fractured his ribs and split his head open.
South-African born Mr Rogers tried six different treatments before he was referred to the sleep clinic at Papworth Hospital in Cambridge.
He said: "I am not violent - I do not swear or curse and I can't believe what I do at night."
His wife Linda has had to sleep in a different room to avoid her husband lashing out.
Doctors at Papworth decided to try a new £13,000 a year drug mix, which acts to break the circuit between the sleeping brain and muscles in the body.
Mr Rogers said: "Some people have a glass of whisky before going to bed. I just have a potion."
Dr John Shneerson, the director of the sleep clinic, said: "Quite aside from the physical side, the apprehension of what he was going to do at night was a difficult thing to live with.
"He is definitely unique in Britain and probably in Europe."
Mr Roger's story will be featured on Sleep Clinic on BBC 1 on Monday 26 March.