With Gertie C., the hallucinations (precipitated by the addition of amantadine to her L-dopa) were less benign. Within three hours of receiving the first dose, she became intensely excited and deliriously hallucinated. She would cry out, "Cars bearing down on me, they're crowding me!" She also saw faces "like masks popping in and out." Occasionally she would smile rapturously and exclaim, "Look what a beautiful tree, so beautiful," and tears of pleasure would fill her eyes.

In contrast to these postencephalitic patients, people with ordinary Parkinson's disease do not usually experience visual hallucinations until they have been on medication for many months or years. By the 1970s, I had several such patients who had started to get hallucinations, which were predominantly (though not exclusively) visual. Sometimes these began as webs and filigrees or other geometrical patterns; other patients experienced complex hallucinations, usually of animals and people, from the start. Such visions might seem quite real (one patient had a nasty fall while chasing a hallucinatory mouse), but the patients soon learned to distinguish them from reality and ignore them. At the time I could find almost nothing in the medical literature about such hallucinations, although it was sometimes said that L-dopa might make patients "psychotic." But by 1975, more than a quarter of my patients with ordinary Parkinson's disease, while otherwise doing well on L-dopa and dopamine agonists, had found themselves living with hallucinations.

Ed W., a designer, started to get visual hallucinations after he had been on L-dopa and dopamine agonists for several years. He realized that they were hallucinations and regarded them largely with curiosity and amus.e.m.e.nt; nevertheless, one of his physicians declared him "psychotic"-an upsetting misdiagnosis.

He often feels himself "on the verge" of hallucination, and he may be pushed over the threshold at night, or if he is tired or bored. When we had lunch one day, he was having all sorts of what he calls "illusions." My blue pullover, draped over a chair, became a fierce chimerical animal with an elephant-like head, long blue teeth, and a hint of wings. A bowl of noodles on the table became "a human brain" (though this did not affect his appet.i.te for them). He saw "letters, like teletype" on my lips; they formed "words"-words he could not read. They did not coincide with the words I was speaking. He says that such illusions are "made up" on the spot, instantaneously and without conscious volition. He cannot control or stop them, short of closing his eyes. They are sometimes friendly, sometimes frightening. For the most part, he ignores them.

Sometimes he moves from "illusions" to frank hallucinations. One such was a hallucination of his cat, which had gone to the vet for a few days. Ed continued to "see" her at home, several times a day, emerging from the shadows at one end of the room. She would walk across the room, paying no attention to him, and then disappear into the shadows again. Ed realized at once that this was a hallucination, and had no desire to interact with it (though it aroused his curiosity and interest). When the real cat came back, the phantom cat disappeared.1

In addition to such isolated or occasional hallucinations, people with Parkinson's may develop elaborate and frightening hallucinations, often of a paranoid sort. Such a psychosis took hold of Ed toward the end of 2011. He started to have hallucinations of people who entered his apartment, emerging from "a secret chamber" behind the kitchen. "They invade my privacy," Ed said. "They occupy my s.p.a.ce.... They are very interested in me-they take notes, take photos, rifle through my papers." Sometimes they had s.e.x-one of the intruders was a very beautiful woman, and sometimes three or four of them would occupy Ed's bed when he was not using it. These apparitions never appeared if he had real visitors or when he was listening to music or watching a favorite TV show; nor would they follow him when he left his apartment. He often regarded these persecutors as real and might say to his wife, "Take a cup of coffee to the man in my office." She always knew when he was hallucinating-he would stare fixedly at one point or follow an invisible presence with his eyes. Increasingly, he started to talk with them-or at them, for they never replied.

Ed's neurologist, on hearing this, advised him to have "a drug holiday," to stop all his anti-Parkinson's medications for two or three weeks, but this left Ed so incapacitated he could hardly move or speak. He then planned a gradual reduction of medication, and, two months later, on half his previous dose of L-dopa, Ed's hallucinations, his fears, and his psychosis have cleared completely.

In 2008, Tom C., an artist, came to my office for a consultation. He had been diagnosed with Parkinson's disease and put on medication about fifteen years earlier. Two years later, he started to experience "misperceptions," as he calls them (like the others, he avoids the term "hallucinations"). He is fond of dancing-he finds that this can unfreeze him, releasing him, for a while, from his parkinsonism. His first misperceptions occurred when he was in a nightclub; the skin of the other dancers, even their faces, seemed to be covered with tattoos. At first he thought the tattoos were real, but they started to glow and then to pulse and writhe; at that point he realized they must be hallucinatory. As an artist and a psychologist, he was intrigued by this experience-but frightened, too, that it might be the beginning of uncontrollable hallucinations of all sorts.

Once, while sitting at his desk, he was surprised to see a picture of the Taj Mahal on his computer monitor. As he gazed, the picture became richer in color, three-dimensional, vividly real. He heard a vague chanting, of the sort he thought might be a.s.sociated with an Indian temple.

Another day, while he was lying on the floor, frozen by his parkinsonism, the reflections on a fluorescent ceiling lamp started to change into old photographs, mostly in black and white. These seemed to be photographs from earlier days, mostly of family, with some of strangers. "I had nothing else to do" in this immobilized state, he said, so he happily indulged this mild hallucinatory pleasure.

For Ed W. and Tom C., hallucinations usually remain on the "misperception" side, but Agnes R., a seventy-five-year-old lady who has had Parkinson's disease for twenty years, has had frank visual hallucinations for the last decade. She is, as she says, "an old hand" at hallucinations: "I see a whole array of things, which I enjoy-they are fascinating; they don't frighten me." In the clinic waiting room, she had seen "women-five of them-trying on fur coats." The size, color, solidity, and movement of these women looked perfectly natural; they seemed absolutely real. She knew that they were hallucinations only because they were out of context: no one would be trying on fur coats on a summer day in a doctor's office. In general, she is able to distinguish her hallucinations from reality, but there have been exceptions: on one occasion, seeing a furry black animal leap onto the dining table, she jumped. At other times, while walking, she has stopped abruptly to avoid b.u.mping into a hallucinatory figure just in front of her.

Agnes most often sees apparitions from the windows of her twenty-second-floor apartment. From here, she has "seen" a skating rink on top of a (real) church, "people in tennis courts" on neighboring rooftops, and men working just outside her window. She does not recognize any of the people she sees, and they continue whatever they are doing without paying any attention to her. She watches these hallucinatory scenes with equanimity and sometimes with enjoyment. (Indeed, I got the impression that they help her pa.s.s the time-time which now seems to pa.s.s more slowly with her relative immobility and difficulties reading.) Her visions are not like dreams, she said; nor do they resemble fantasies. She has a great love for travel and for Egypt in particular, but she has never had "Egyptian" hallucinations or travel ones.

She sees no patterns to her hallucinations-they may come at any time of day, when she is busy with others or when she is alone. They seem to have nothing to do with current events, with her feelings, thoughts, or moods, or with the time of day she takes her medication. She cannot will them to come, or will them away. They superimpose themselves on what she is looking at and vanish, along with actual visual perception, when she closes her eyes.

Ed W. often describes a persistent feeling of a "presence"-something or someone he never actually sees-on his right. Professor R., while doing very well on L-dopa and other anti-parkinsonian drugs, also has "a companion" (as he calls it), just out of sight on his right. The sense of someone there is so strong that he sometimes wheels round to look, though there is never anyone to be seen. But his chief illusion is the transformation of print, words and sentences, into musical notation. The first time this happened was about two years ago. He was reading a book, turned away for a few seconds, and found, when he returned to the book, that the print had been replaced by music. This has occurred many times since, and may also be induced by staring at a page of print. Occasionally the dark border of his bath mat turns into staves and lines of music. There is always something-letters or lines-that is transformed into music; this may be why he regards these as "illusions," not hallucinations.

Professor R. is a very good musician; he started to play the piano when he was five and still plays for many hours a day. He is curious about his illusions, and he has done his best to transcribe or play the illusory music. (His best chance of "catching" this phantom music, he has found, is to set up a newspaper on the music stand and play it as soon as the newsprint turns into music.) But the "music" is scarcely playable, because it is always very highly ornamented, with innumerable crescendo and decrescendo markings, while the melody line is three or more octaves above middle C, and so may have half a dozen or more ledger lines above the treble staff.

Seeing music has been described to me by others (see this page). Esther B., a composer and music teacher, wrote to me that, twelve years after being diagnosed with Parkinson's, she started to have "a rather peculiar visual phenomenon." She described this in detail:

When I look at a surface-like a wall, or a floor, or a garment someone is wearing, or a curved surface like a tub or sink, or other surfaces too numerous to mention-I see a sort of collage of music scores superimposed upon the surface, especially with my peripheral vision. When I try to focus on any one image, it dims out or disappears elusively. These images of music scores come unbidden and are especially vivid after I've been working with any written music. The images always appear more or less horizontal, and if I tilt my head one way or the other, the horizontal images will tilt accordingly.

Howard H., a psychotherapist, began to notice tactile hallucinations soon after being diagnosed with Parkinson's, as he wrote:

I would feel that the surfaces of various objects were covered by a film of fuzz, like peach fuzz, or the down in a pillow. It could also be described as cotton candy or spider webs. Sometimes the webs and fuzz can get very "lush," as when I reach down to pick up something that has fallen under my desk and my hand feels as if it has become submerged in a huge pile of this "stuff." But when I try to scoop up that pile, I see nothing and yet feel that I have a large amount of this "stuff" in my hands.

Is the use of L-dopa wholly responsible for such effects? Can L-dopa be regarded as a hallucinogenic drug? This seems unlikely in view of the fact that it is used in treating other conditions (such as dystonias) without provoking any hallucinations. Is there then something in the parkinsonian brain, or at least in some parkinsonian brains, which may predispose to visual hallucinations?2

Too often, parkinsonism is seen as no more than a movement disorder, but it may also involve a number of other aspects, including sleep disturbances of various sorts. People with Parkinson's may sleep poorly at night and often have chronic sleep deprivation. Their sleep may be marked by vivid and sometimes bizarre dreams, or nightmares in which they are awake but paralyzed, helpless to combat dream images being superimposed on their waking consciousness. All of these factors additionally predispose to hallucination.

In 1922 the French neurologist Jean Lhermitte described the sudden onset of visual hallucinations in an elderly patient-people in costume, children playing, animals around her (she would sometimes try to touch them). The patient had insomnia at night and drowsiness in the daytime, and her hallucinations tended to come at dusk.

Though this lady had dramatic visual hallucinations, she had no visual impairments and no lesions in the visual cortex. But she had neurological signs suggesting an unusual pattern of damage in parts of the brain stem, the midbrain, and the pons. It was well known at this point that lesions in the visual pathway could cause hallucinations, but it was not clear how damage in the midbrain-not a visual area-could do so. Lhermitte thought such hallucinations might go with a derangement of the sleep-wake cycle, that they were essentially dreams or dream fragments invading daytime consciousness.

Five years later, the Belgian neurologist Ludo van Bogaert reported a somewhat similar case-his patient suddenly started seeing the heads of animals projected on the walls of his house at dusk. There were neurological signs similar to those of Lhermitte's patient, and van Bogaert also surmised midbrain damage. When his patient died, a year later, an autopsy revealed a large midbrain infarction involving (among other structures) the cerebral peduncles (hence his coinage of the term "peduncular hallucinations").

In Parkinson's disease, postencephalitic parkinsonism, and Lewy body disease, there is damage to the brain stem and a.s.sociated structures, as there is in peduncular hallucinosis-though the damage occurs gradually and not abruptly, as with a stroke. In all of these degenerative diseases, however, there may be hallucinations, as well as sleep, movement, and cognitive disorders. But the hallucinations are markedly different from those of CBS; they are nearly always complex rather than elementary, often multisensory, and more apt to lead to delusions, which CBS alone rarely does. The hallucinations of brain-stem origin seem to be a.s.sociated with abnormalities in the acetylcholine transmitter system-abnormalities that may be aggravated by giving the patient L-dopa or similar drugs, which heighten the dopamine load on an already fragile and stressed cholinergic system.

People with ordinary Parkinson's disease may be active and retain their intellectual powers for decades-Thomas Hobbes, the philosopher, for instance, developed "the shaking palsy" around the age of fifty, when he was completing his Leviathan, but remained intellectually intact and creative, though motorically disabled, into his nineties. But it has been increasingly recognized in the last few years that there is a more malignant form of parkinsonism, one accompanied sooner or later by dementia and by visual hallucinations even in the absence of L-dopa. Examination of the brain at autopsy in such patients may show abnormal aggregates of protein (so-called Lewy bodies) inside the nerve cells, mostly in the brain stem and basal ganglia but also in the visual a.s.sociation cortex. The Lewy bodies, it is conjectured, may predispose patients to visual hallucinations even before they are put on L-dopa.

Edna B. seems to have this disease, though the diagnosis of Lewy body disease cannot be made with certainty in life without doing a brain biopsy. Mrs. B. enjoyed excellent health until her mid-sixties, but in 2009 she developed some tremor in the hands, her first symptoms of parkinsonism. By the summer of 2010 her symptoms included some slowing of movement and speech as well as problems with memory and concentration-she would forget words and thoughts, lose the thread of what she was saying and thinking, and, most distressingly of all, she had hallucinations.

When I saw her in 2011, I asked her what her hallucinations were like. "Horrible!" she said. "It's like watching a horror movie, and you're part of it." She saw little people ("Chuckys") running around her bed at night; they seemed to be talking to each other, she saw their gestures and their lips move, but she could not hear any speech. On one occasion she tried to speak to them. Although they looked frightening and (she thought) had evil intentions, they never molested or approached her, though once one of them sat on her bed. But far worse were certain scenes enacted before her. "I saw my son murdered right in front of my eyes," she told me. ("It was Darkside stuff," her husband interpolated.) Once, when her husband visited, she said, "What are you doing here? They just had your funeral at Sacred Heart Church." She often saw rats, and sometimes felt them in her bed. She also felt "fish" nibbling at her feet. Sometimes she had hallucinations of being part of an army marching into battle.

When I asked if she had any pleasant hallucinations, she said that she had sometimes seen people "in Hawaiian dress" in the corridor or outside her window, getting ready to play music for her, though she never actually heard any music. What she did hear, however, were various noises-especially the sound of running water. No voices. ("Good thing I didn't have those," she said, "or they'd think I was really crazy.") There have been some olfactory hallucinations, too: "people around me with different kinds of scents."

When her hallucinations started, Mrs. B. was understandably terrified, and took them for reality-"I did not even know the word 'hallucination,' " she said. Then she found herself more able to distinguish hallucinations from reality, but this did not prevent her from being frightened when they occurred. She always looked to her husband for reality testing; she would ask him whether he saw, heard, felt, or smelled some of the things she did. Sometimes she would have distortions of vision-her husband's face would be disfigured by a down-curving, sneering smile or occasionally his mouth would be upturned, "like a smiley face." A particularly strange and frightening hallucination occurred recently. There is a poster of a Native American chief hanging above her bed, and this came to life for Mrs. B. the other day; the chief stepped out of the frame and seemed to be standing in the bedroom. To rea.s.sure her, her husband waved his hands in front of the picture to dissipate the hallucination-and the chief seemed to disintegrate, but then she felt she was disintegrating, too. On another occasion, clothes in the bedroom "started walking around," and she had to have her husband shake a pair of jeans to show that it was just this, and nothing more.

Hallucinations may also occur in other types of dementia, including moderately advanced Alzheimer's disease, though less often than they do in Lewy body disease. In such cases, hallucinations may give rise to delusions, or they may stem from delusions. There may also be, in Alzheimer's or other types of dementia, delusions of duplication or misidentification. One patient of mine, sitting next to her husband on an airplane, suddenly saw him as "an imposter" who, she believed, had murdered her husband and was now trying to take his place. Another patient of mine, while she recognized the nursing home she was in by day, felt that she had been transferred to a cunning "duplicate" of the home each night. Sometimes psychoses can be centered on delusions of persecution, and occasionally these lead to violent behavior: one such patient a.s.saulted a harmless neighbor, whom she felt was "spying" on her. Hallucinations in Alzheimer's disease, like those of Lewy body disease, are usually embedded in a complex matrix of sensory deceptions, confusion, disorientation, and delusions, and are rarely isolated, "pure" phenomena as in Charles Bonnet syndrome.

I worked for many years with the eighty deeply parkinsonian postencephalitic patients I described in Awakenings. Many of them had been "frozen" for decades, virtually immobilized by their disease. Once I got to know them well (after they had been enabled to move and talk by L-dopa), I found that perhaps a third of them had experienced visual hallucinations for years before L-dopa was introduced-hallucinations of a predominantly benign and sociable sort. I was not sure why they hallucinated in this way, but I thought it might be related to their isolation and social deprivation, their longing for the world-an attempt to provide a virtual reality, a hallucinatory subst.i.tute for the real world which had been taken from them.

Gertie C. had had a half-controlled hallucinosis for decades before she started on L-dopa-bucolic hallucinations of lying in a sunlit meadow or floating in a creek near her childhood home. This changed when she was given L-dopa, and her hallucinations a.s.sumed a social and sometimes s.e.xual character. When she told me about this, she added, anxiously, "You surely wouldn't forbid a friendly hallucination to a frustrated old lady like me!" I replied that if her hallucinations had a pleasant and controllable character, they seemed rather a good idea under the circ.u.mstances. After this, the paranoid quality dropped away, and her hallucinatory encounters became purely amicable and amorous. She developed a humor and tact and control, never allowing herself a hallucination before eight in the evening and keeping its duration to thirty or forty minutes at most. If her relatives stayed too late, she would explain firmly but pleasantly that she was expecting "a gentleman visitor from out of town" in a few minutes' time, and she felt he might take it amiss if he was kept waiting outside. She now receives love, attention, and invisible presents from a hallucinatory gentleman who visits faithfully each evening.

1. My colleague Steven Frucht described to me a hallucination experienced by a patient of his, an intellectually intact woman who has been treated with medications for Parkinson's disease for more than fifteen years. Her hallucinations, however, started only a year ago. She also sees a cat-a grey cat with "beautiful" eyes which wears a serene, "beautiful expression" on its face and seems to be of a most friendly disposition. To her own surprise (for she has never liked cats), she enjoys visits from the grey cat and worries that "something may happen to him." Though she knows the cat is a hallucination, he seems very real to her: she can hear him coming, feel the warmth of his body, and touch him if she wishes. The first time the cat appeared, wanting to rub against her legs, she said, "Don't touch me, don't get too close." And since then the cat has kept a decorous distance. Occasionally, in the afternoon, the cat is joined by a large black dog. When Dr. Frucht asked her what happens when the cat sees the dog, she replied that the cat "looks away and is peaceful." She later remarked, "He is fulfilling his purpose in coming to visit me."

2. Impairment of the sense of smell may appear early in Parkinson's disease and may perhaps predispose to smell hallucinations as well. But even in the absence of a noticeable impairment of smell, as Landis and Burkhard suggested in a 2008 paper, patients with incipient Parkinson's disease may have olfactory hallucinations before they develop motor symptoms.

6

Altered States

Humans share much with other animals-the basic needs of food and drink or sleep, for example-but there are additional mental and emotional needs and desires which are perhaps unique to us. To live on a day-to-day basis is insufficient for human beings; we need to transcend, transport, escape; we need meaning, understanding, and explanation; we need to see overall patterns in our lives. We need hope, the sense of a future. And we need freedom (or at least the illusion of freedom) to get beyond ourselves, whether with telescopes and microscopes and our ever-burgeoning technology or in states of mind which allow us to travel to other worlds, to transcend our immediate surroundings. We need detachment of this sort as much as we need engagement in our lives.

We may search, too, for a relaxing of inhibitions that makes it easier to bond with one another, or for transports that make our consciousness of time and mortality easier to bear. We seek a holiday from our inner and outer restrictions, a more intense sense of the here and now, the beauty and value of the world we live in.

William James was deeply interested, throughout his life, in the mystagogic powers of alcohol and other intoxicants, and he wrote about this in his 1902 book The Varieties of Religious Experience. He described, too, his own transcendent experiences with nitrous oxide:

Our normal waking consciousness, rational consciousness, as we call it, is but one special type of consciousness, whilst all about it, parted from it by the filmiest of screens, there lie potential forms of consciousness entirely different.... Looking back on my own experiences, they all converge towards a kind of insight to which I cannot help ascribing some mystical significance. The keynote of it is invariably a reconciliation. It is as if the opposites of the world, whose contradictoriness and conflict make all our difficulties and troubles, were melted into unity.... To me [this sense] only comes in the artificial mystic state of mind.

Many of us find the reconciliation that James speaks of and even Wordsworthian "intimations of immortality" in nature, art, creative thinking, or religion; some people can reach transcendent states through meditation or similar trance-inducing techniques or through prayer and spiritual exercises. But drugs offer a shortcut; they promise transcendence on demand. These shortcuts are possible because certain chemicals can directly stimulate many complex brain functions.