On January 11 2000, while teaching a Shakespeare masterclass in Paris, Jane Lapotaire collapsed with a massive brain haemorrhage, the result of a burst aneurysm in the middle cerebral artery. She spent three and a half weeks largely unconscious in intensive care as she recovered from six hours of surgery to clip the aneurysm and two angioplasty operations to prevent her brain going into spasm and killing her. As it turned out, however, nearly dying was to be the easy part.

The months which followed this neurological catastrophe were to see one of the most distinguished actresses of her generation - a specialist in playing strong women from Cleopatra to Marie Curie - reduced to a combination of helpless child and obnoxious adult. "I'd become the monster I'd always feared I was, times a thousand," she says, "Brain surgery is the most invasive kind you can have and it exacerbates every characteristic. So I was obstinate, querulous, irritable, confrontational, strident - and those were the good bits." At other times she would be full of rage and venomous hatred for the whole of humankind.

Coupled with this were headaches so excruciating that she would be driven to banging her head against the wall. Such was her despair at times that, if it had not been for the terrible legacy that suicide would have left her son Rowan, she might have killed herself.

Time Out of Mind, which is published this week, is Lapotaire's story of her long haul back from the abyss. It is not just an unsparing and heart-rending account of her own illness but an eloquent plea of behalf of all brain-injured people.

"I wrote the book because I was furious and outraged at the lack of knowledge, mine included, about the subject. We are very bad at relating to what we can't see and brain injuries are invisible; the minute your hair grows back no one knows. If you can walk and talk, you're allowed home. I was given no warning about anything being different."

But things were about as different as they could be. For a start, she had complete dissociation from her body: "If someone had said, 'Those are not your arms and legs there,' I would have accepted it. I also felt that, somehow, I had no centre. I don't think I felt as if my brain went back inside my body for 18 months."

After staying with a friend for a few weeks she returned to her cottage and tried to get on with life, but the most simple tasks seemed overwhelming. She could not cope with noise, traffic or people. "It was like the Midas touch in reverse. Everything I touched I spoiled. Every time I opened my mouth I screamed at or angered people so much that they argued back or shouted at me. Friendship after friendship went down the toilet. I know what terror is because I lived with it month after month. I thought I was in hell."

From being a woman who, following her divorce, had combined a glittering career with single motherhood she was now daunted by a pile of ironing. "I wasn't used to spending a day in which the big event would be a trip to Putney high street," she says, "but life as I knew it had completely disappeared. People who have husbands and wives or partners have someone who can tell the doctor 'She's not normally like this,' but I lived alone so there was no one."

And so she struggled on until, nine months after the haemorrhage, she got an appointment at the National Hospital for Neurology and Neurosurgery in London, where the consultant told her that her behavioural and emotional problems, her fatigue and depression and inability to handle the slightest stress, were classic symptoms of a brain surgery patient. He also suggested neuro-psychology rehabilitation which would use cognitive therapy to help her recognise the problems and work out thinking and coping strategies to deal with them. "That's what saved my life," she says, "because it taught me how to handle the person I am now."

The therapy would deal teach her to pace herself, to rest and relax, to work out a timetable of what was and was not possible in a day. It would also help her to recognise events or situations which would trigger distress and how to avoid or handle them. Some of the incidents she dubbed HBOs or Heads Bitten Off.

"I still get what I call the zaps which are like angry wasps buzzing in my brain, but instead of being frightened of them and other signs like dizziness or fatigue or feeling spaced out, I now listen to them as friends warning me to rest and take things more slowly. And I know when I have to excuse myself from certain events, especially ones that involve crowds."

Such limitations become clear during our interview. At times, in order to emphasise a point, she performs not just a re-creation of her own pain but that of fellow sufferers she has met. It is dazzling, high octane stuff, especially at close range. After about an hour though she starts to falter: the noise of the traffic through the open window distresses her, she stumbles over words and becomes tearful. It is a poignant reminder of the effort the brain-injured must make just to get through the day.

"We've somehow lost the notion of convalescence," she says. "We don't live in a world where you can be ill for any length of time. You can have the odd weekend off with a cold or 'flu but anything more is regarded as suspect. I don't think even I really took on board how seriously ill I had been until about six months ago."

She has also been helped by support groups such as the one run by Basic, the Brain and Spinal Injuries Charity, by osteopathy and physiotherapy and by the anti-depressant amitriptyline which also calms the headaches. Her religious faith has always been central to her life and although not a Quaker herself she found solace at one of their retreats and is now a regular attender at their services. She is also in a new relationship with a man she identifies only as the Godsend.

The price of her illness has been enormous: physically, emotionally and financially. One of the themes of the book is the constant wrestling with pension funds and private health insurance companies, and she urges everyone to read the small print in contracts regarding chronic conditions. Although she manages some teaching and poetry recitals she is unlikely ever to regain the stamina required for full-length stage plays, and after losing four film jobs in a row has decided, at the age of 58, not to put herself up for any more. She misses the work itself hugely as well as the camaraderie of other actors.

And yet she has never wished that the brain haemorrhage had not happened. "This is the hand I got dealt. This is part of my soul's journey on this planet. Some people say there is no point in suffering but I believe there is. If you learn from it, it hones the soul. When you're that ill, when you're no longer a mother or a wife or a leading actress or an author but just a very, very sick body then that is very humbling and you also get a great sense of other people's needs.

"If I'd not collapsed in a public place I'd be dead. I am very lucky to be given a second chance and I want to make use of it. I want other patients to know they're not alone and that however long and hard the journey they should hang on in there"

The facts

* A brain aneurysm is a bulge in a brain artery wall making it more likely to rupture.

* Some estimates suggest that as many as one in five of the population will have them without ever experiencing any problems.

* The incidence of aneurysmal subarachnoid haemorrhage such as Lapotaire's is one in 10,000 of the population every year (6,000 people in the UK), the proportion of women to men is 3/2. Some patients may have pain or a drooping eyelid but most will have no prior symptoms.

* Only one in four survive.

* When the haemorrhage happens blood is pumped through the brain at high pressure, tearing into and destroying brain tissue.

* Causes vary: a genetic predispostion exacerbated by high blood pressure and loss of elasticity in the arteries due to smoking and high blood fats. The contribution played by stress is unclear.

* The long-term consequences can be devastating. Brain haemorrhage patients report memory impairment, loss of concentration and fine motor coordination, headaches, depression and anxiety, problems sleeping and personality changes. Many lose their jobs or are demoted.

John Firth, consultant neurosurgeon and one of the founders of Headway, the Brain Injury Association, says, "If the frontal lobes of the brain are damaged either by a haemorrhage or a bash on the head, then social behaviour tends to be affected. They are the part of the brain that makes us civilised, that enables us to subdue our own unpleasant traits and tolerate them in others. They made it possible for our ancestors to live in a cave with their in-laws."

Recovery, he says, depends on good nursing, careful management, full explanations and information to patients and their families, appropriate therapy and time. "We tend to be victims of our own success in that people come in at death's door and we save them and then when they're fit enough we kick them out. We need to remember that this is a very long process which takes at least a couple of years."

Time Out of Mind is published by Virago at £16.99
Headway 0115 924 0800 www.headway.org.uk
BASIC Brain and Spinal Injuries Charity email basic_charity@compuserve.com
British Brain and Spine Foundation 0207 793 5909 www.tna-uk.org.uk
Rehabilitation Network 0207 467 8575 www.rehabnetwork.info