Oliver Sacks: On the Move - A Life (Picador)

If this eccentric had been one of the patients Oliver Sacks has written about in works such as The Man Who Mistook His Wife For A Hat, one would not be surprised. Nor, however, does it come as any great shock to learn that the man with the spectroscope was none other than the great neurologist and writer himself. As becomes abundantly clear in this forthright, touching memoir, Dr Sacks is a fascinating case study in his own right, albeit not in a medical sense.

Naturally, Sacks does not see himself in this light. In the opening chapters, one fears that Sacks's incorrigible interest in human nature, the very thing that made books such as Awakenings and An Anthropologist On Mars so enthralling, has oddly little interest in his own personality. As he describes his wartime London childhood, as one of four sons of a father who was a GP, and a mother who was a surgeon, the insights one gleans into his character at this early stage are found more in incidental detail than in deliberate revelation. One such is the teacher's school report when he was 12, stating, "Sacks will go far, if he does not go too far". Another was his precociously hungry mind which had to be perpetually fed. As a student at Oxford, he spent the prize money he won for an essay (written when drunk), on the 12 volumes of the Oxford English Dictionary. "I was to read the entire dictionary through when I went on to medical school, and I still like to take a volume off the shelf , now and then, for bedtime reading."

By turns brilliant and erratic, he once delivered a university essay to his tutor, carefully turning pages as he read. Only when asked to repeat a sentence did it become clear that the notepad was blank and he was composing it on the spot. "Remarkable, Sacks, very remarkable. But in future I want you to write your essays," said his professor.

From the outset Sacks's unusual mind was evident, but as this memoir unfolds, one realises how very closely he sailed to disaster. The catalyst for the self-loathing and drug experimentation that marred his twenties and thirties might be attributable to his mother's horror when he announced he was gay. But equally, pathological shyness might be enough to explain the need for chemical release. As he writes of the 1960s, when he'd go into a bar to meet people, "I would agonize, wedged into a corner, and leave after an hour, alone, sad, but somehow relieved." This insight into his nature comes late in the book, and it's tempting to wonder if its tardiness also reflects the time that had to elapse before he became fully aware of himself.

An escape from his crippling inhibitions was found in a love of motorbikes, one of which features on the jacket of the book, with a butch-looking Sacks astride it. Another unlikely pastime was weightlifting, a sport in which he occasionally excelled, though at great cost, in later years, to his back.

Leaving London for Canada in 1960 at the age of 27, Sacks thought this was merely a temporary escape from a city too full of medics from his immediate and extended family. Instead, it proved to be a lifelong relocation, and he spent the rest of his career moving between California and New York.

For many, Sacks's face is overlaid by that of Robin Williams, who played him as a young doctor in Awakenings. This was the film of the book he wrote about his revolutionary and only partially successful work with patients suffering near catatonia and other debilitating symptoms after contracting encephalitis lethargica in the early 1920s. Some began to respond to medication with L-dopa under his care, though almost all slipped gradually back to their unresponsive previous selves. The genesis of the book, during his time in Beth Abraham Hospital in the Bronx, and the trouble he had in finding a way to write it, are movingly recounted. "Such an experience is not given to one twice in a lifetime, nor, usually, even once. Its preciousness and depth, its intensity and range, made me feel I had to articulate it somehow..."

Sacks focuses less on the medical aspect of the story than on the mechanics of finding the right way to tell it, a dilemma other doctors will understand. Part of the tale's charm is the role his mother played in encouraging him to write it. One senses that this shared enterprise made reparation for the hurt she had caused, so many years before.

A series of vivid case studies, Awakenings drew plaudits from friends such as Wystan Auden, but had virtually no attention in America, and led to an unsettling silence from his medical colleagues. It was not until the publication of The Man Who Mistook His Wife For A Hat that he became a public figure, and even then many medics remained sceptical or suspicious. Writing about patients in this way was deemed a little discreditable, both to Sacks and the profession.

He continued undeterred, proving himself as dedicated to the act of composition as to doctoring. While the process of writing sounds tortuous - constant rewrites and obsessive footnoting revealing the mania of a mercurial intellect - the outcome was to make the reading public aware of the depths of trouble the human brain can cause. That he made such tragic predicaments compelling rather than prurient is testament to the quiet, honest and unsentimental humanity he brings to his work. One can speculate whether Sacks's professional insightfulness is rooted in his own unorthodox character and outlook. Certainly, as excellent a storyteller as he is, he has had almost as many setbacks as successes. Fired from jobs, bullied or overlooked, he was obviously a misfit in the ultra-conservative corridors of medicine: a misfit until it came to diagnosis and care, when even his detractors could not fault him.

As much a literary history of the origins of his many books as unalloyed autobiography, On The Move is untainted by artifice or ego. It is winsome and witty, inspiring and encouraging, but it is also full of profound human sadness. This, it seems, is the arena where Sacks is most comfortable - and where he has been most needed.