When a schoolfriend told a neighbour he had seen a body, the boy said it was a blow-up dummy his father had left on the floor, the inquest at Hammersmith, west London, was told.
The boy, who cannot be named for legal reasons, lied to friends and neighbours, constantly claiming his mother was out. He even invited two schoolfriends to stay at the house in Acton, west London.
The woman, who died in Hammersmith Hospital on 11 February, had suffered brain damage giving birth to her son and was awarded pounds 200,000 damages in the High Court in 1990.
Dr John Burton, the coroner, who recorded a verdict of death by natural causes, said: 'I make no comment on the account of her son . . . it does seem that he concealed the fact that his mother was laying for days, but it does not affect the cause of death. She would have died anyway.'
Dr Christopher Foster, a pathologist, said the 45-year-old woman died from a stroke. She had suffered from fits and black- outs, the inquest was told.
The dead woman's GP, Dr Helen Sapper, said in a written statement to the inquest that the woman, had high blood pressure but refused to go to hospital and was warned she might have a stroke. She also had a habit of hyperventilating which led to fits. A neighbour said she last saw the woman on 27 January, when she was carried inside after suffering dizziness on an outing to the shops. The neighbour said she agreed to visit the shops the next day but that as she left the woman said: 'If anything happens to me put all my money in my son's book and don't let them take him out of the country.'
Over the following few days the neighbour frequently called at the house but was unable to get a reply. When she next saw the son and asked how his mother was he told her: 'She is feeling much better and she even went out to do some shopping.'
The son had a key to the flat where he lived alone with his mother and was seen going in and out but spent much of his time in a local video shop with friends.
The neighbour, who is now caring for the boy, at present a ward of court, said she believed he 'used up all the money left around the house'.
The boy took two friends to the neighbour's house at 8pm on 7 February saying they were invited to stay but his mother had not come home. The neighbour said that by 10pm she thought something was wrong and put the children to bed.
The next day the neighbour said one of the children told her that there was a body in the flat. The boy told her it was a dummy.
The neighbour said she then decided to see what was going on. 'I saw him coming from his flat. I said where is your mum? He said 'Oh, didn't you pass her? She was just up the road'. I said I've had enough of your lies. Open that door. We went in. She was laying on the floor just inside the front room.'