Authors: Oliver Sacks
I
was therefore surprised and intrigued to receive the following letter from a physician in England, about his eighty-six-year-old father, Gordon H., who had long-standing glaucoma and macular degeneration. He had never had hallucinations before, but recently he had had a small stroke affecting his right occipital lobe. He was “quite sane and largely intellectually undiminished,” his son wrote, but
he has not recovered vision and retains a left hemianopia. He has, however, little awareness of his visual loss as his brain appears to fill in the missing parts. Interestingly, though, his visual hallucinations / filling in always seem to be context-sensitive or
consistent
. In other words, if he is walking in a rural setting, he can be aware of bushes and trees or distant buildings in his left visual field, which when he turns to engage his right side, he discovers are not really there. The hallucinations do, however, seem to be filled in seamlessly with his ordinary vision. If he is at his kitchen bench, he “sees” the entire bench, even to the extent of perceiving a certain bowl or plate within the left side of his vision—but which on turning disappear, because they were never really there. Yet he definitely sees a
whole
bench, with no clear separation between parts composed of hallucination and true perception.
Gordon H.’s normal visual perception to the right side, one might think, by its normalcy and detail, would immediately show up the relative poverty of the mental construct, the hallucination,
on the left. But, his son asserts, he cannot tell one from the other—there is no sense of a boundary; the two halves seem continuous. Mr. H.’s case is unique, to my knowledge.
2
He has none of the outlandish, obviously out-of-context hallucinations commonly reported in hemianopia. His hallucinations blend perfectly well with his environment and seem to “complete” his missing perception.
I
n 1899, Gabriel Anton described a singular syndrome in which patients totally blind from cortical damage (usually from a stroke affecting the occipital lobes on both sides) seemed to be unaware of it. Such patients may be sane and intact in all other ways, but they will insist that they can see perfectly well. They will even behave as if sighted, boldly walking in unfamiliar places. If, in so doing, they collide with a piece of furniture, they will insist that the furniture has been moved, that the room is poorly lit, and so on. A patient with Anton’s syndrome, if asked, will describe a stranger in the room by providing a fluent and confident, though entirely incorrect, description. No argument, no evidence, no appeal to reason or common sense is of the slightest use.
It is not clear why Anton’s syndrome should produce such erroneous but unshakable beliefs. There are similar irrefutable beliefs in patients who lose the perception of their left side and the left side of space but maintain that there is nothing missing, even though we can demonstrate convincingly that they live in a hemi-universe. Such syndromes—so-called
anosognosias—occur only with damage to the right half of the brain, which seems to be especially concerned with the sense of bodily identity.
An even stranger twist was given to the matter in 1984, with the publication of a paper by Barbara E. Swartz and John C. M. Brust. Their patient was an intelligent man who had lost the sight in both eyes from retinal injuries. Normally, he recognized that he was blind and behaved as if blind. But he was also an alcoholic, and twice, while on a drinking binge, he believed that his sight had returned. Swartz and Brust wrote:
During these episodes, he believed he could see; for example, he would walk about without asking for assistance, or he would watch television, and he claimed he could then discuss the program with friends.… [He] could not read the 20/800 line on a visual acuity chart, or detect a bright light or hand movements in front of his left eye. Nonetheless, he claimed that he could see, and in response to questions he offered plausible confabulations—for example describing the examining room or the appearance of the two physicians with whom he was speaking. In many particulars his descriptions were wrong, but he did not recognize that they were wrong. However, he did admit that he was also seeing things that were not really there. For example, he described the examining room as being full of little children, all wearing similar attire, some of whom were walking in and out of the room through the walls. He also described a dog in the corner eating a bone, and then noted that the walls and the floor of the room were orange. The children, dog and wall colors he recognized as hallucinations, but [he] insisted that his other visual experiences were real.
Returning to Gordon H., I would hazard a guess that damage to the right occipital lobe has produced a unilateral Anton’s syndrome (though I do not know if such a syndrome has ever been described). His hallucinations (unlike those of Lance’s patients) are informed and shaped by what he perceives in the intact part of his visual field, and mesh seamlessly with his intact perception to the right.
Mr. H. has only to turn his head to discover that he has been deceived, but this does not shake his conviction that he can see equally to both sides. He may, if pressed, accept the term “hallucination,” but if he does so he must feel that, for him, hallucination is veridical, that he is hallucinating reality.
1
. Before seeing Ellen O., I had never heard of visual perseveration of such duration. Visual perseveration of a few minutes may be associated with cerebral tumors of the parietal or temporal lobes or may occur in temporal lobe epilepsy. There are a number of such accounts in the medical literature, including one by Michael Swash, who described two people with temporal lobe epilepsy. One of them had attacks in which “his vision seemed to become fixed, so that an image was retained for several minutes. During these episodes the real world was seen through the retained image, which was clear at first, but then gradually faded.”
Similar perseveration may occur with damage or surgery to an eye. My correspondent H.S. was blinded by a chemical explosion at the age of fifteen but had some sight restored by corneal surgery twenty years later. Following the operation, when his surgeon asked if he could now see the surgeon’s hand, H.S. replied, “Yes”—but then was astonished to see the hand, or its image, preserving its exact shape and position, for several minutes afterward.
2
. In a letter to me, James Lance commented, “I have never encountered hallucination embracing information from the surroundings like Mr. H.’s.”
A
s a medical student at the Middlesex Hospital in London in the 1950s, I saw many patients with delirium, states of fluctuating consciousness sometimes caused by infections with high fevers or by problems like kidney or liver failure, lung disease, or poorly controlled diabetes, all of which may produce drastic changes in blood chemistry. Some patients were delirious from medications, especially those receiving morphine or other opiates for pain. Patients with delirium were almost always on medical or surgical wards, not on neurological or psychiatric wards, for delirium generally indicates a medical problem, a consequence of something affecting the whole body, including the brain, and it disappears as soon as the medical problem has been righted.
It may be that age, even when there is full intellectual function, increases the risk of hallucinations or delirium in response to medical problems and medication—especially with the polypharmacy so often practiced in medicine today.
Working in a number of old-age homes, I sometimes see patients on a dozen or more different medications, which are liable to interact with one another in complex ways and, not uncommonly, tip the patients into delirium.
1
We had one patient on a medical ward at the Middlesex Hospital, Gerald P., who was dying from kidney failure—his kidneys could no longer clear the toxic levels of urea building up in his blood, and he was delirious. Mr. P. had spent much of his life supervising tea plantations in Ceylon. I read this in his chart, but I could have gathered it from what he said in his delirium, for he talked nonstop, with wild associational leaps from one thought to another. My professor had said he was “talking nonsense,” and at first I could make little sense of what he was saying—but the more I listened, the more I understood. I started spending as much time as I could with him, sometimes two or three hours a day. I began to see how fact and fantasy were admixed in the hieroglyphic form of his delirium, how he was reliving and at times hallucinating the events and passions of a long and varied life. It was like being privy to a dream. At first he talked to no one in particular; but
once I started to ask him questions, he responded. I think he was glad that someone was listening; he became less agitated, more coherent in his delirium. He died peacefully a few days later.
I
n 1966, when I started practice as a young neurologist, I began working at Beth Abraham Hospital in the Bronx, a home for those with chronic diseases. One patient there, Michael F., was an intelligent man who, besides other problems, had a very damaged, cirrhotic liver, the result of a severe hepatitis infection. The little liver he had left could not cope with a normal diet, and his protein intake had to be strictly limited. Michael found this hard to take, and every so often he “cheated” by eating some cheese, which he adored. But one day, it seemed, he went too far, for he was found in a near coma. I was called at once, and when I arrived, I found Mr. F. in an extraordinary state, alternating between stupor and delirious agitation. There were brief periods when he would “come together” and show insight into what was going on. “I’m out of this world,” he said at one point. “I’m stoned on protein.”
When I asked him what this state felt like, he said, “like a dream, confused, sort of crazy, spaced out. But I know I’m high, as well.” His attention seemed to dart about, touching on one thing and then another almost at random. He was very restless and had all sorts of involuntary movements. I had my own EEG machine at the time, and, wheeling that into Mr. F.’s room, I found that his brain waves were dramatically slowed—his EEG showed classic slow “liver waves” as well as other abnormalities. Within twenty-four hours of resuming
his low-protein diet, though, Mr. F. was back to normal, as was his EEG.
M
any people—especially children—experience delirium with a high fever. One woman, Erika S., recalled this in a letter to me:
I was 11 years old and was home from school with chicken pox and a high fever.… During a fever spike, I experienced a frightening hallucination for what seemed like a very long time, in which my body seemed to shrink and grow.… With each of my breaths, my body would feel like it was swelling and swelling until I was sure that my skin would burst like a balloon. Then when it felt so excruciating, like I had suddenly grown from a normal sized child to a grotesquely fat person … like a person-balloon … I would look down at myself, sure that I would see my insides bursting out of my inadequate amount of skin, and blood pouring from enlarged orifices that could not contain my swollen body. But I would “see” my normal sized self … and looking would reverse the process.… I would feel like my body was shrinking. My arms and legs would get thinner and thinner … then skinny, then emaciated, then cartoon thin (like the legs on Mickey Mouse in
Steamboat Willie
) and then so pencil thin that I thought my body would disappear altogether.
Josée B. also wrote to me about her “Alice-in-Wonderland syndrome” as a child with fever. She remembered feeling “incredibly small or incredibly large and sometimes both at
the same time.” She also experienced distortions in proprioception, her perception of her own body position: “One evening, I couldn’t sleep in my own bed—every time I lay down on it, I would feel I was standing tall.” She had a visual hallucination, too: “Suddenly I saw cowboys who were throwing apples at me. I jumped onto my mother’s dresser to hide behind a lipstick tube.”
Another woman, Ellen R., had visual hallucinations that took on a rhythmic, pulsing quality:
I would “see” a smooth surface, like glass, or like the surface of a pond.… Concentric rings would spread from the center to the outside edges, as though a pebble had been dropped right in the middle. This rhythm starts slowly [but] … eventually speeds up, so that the surface is constantly agitated, and as this happens, my own agitation is heightened. Eventually the rhythm slows, the surface smooths out, and I become relieved and calmer myself.
Sometimes in a delirium there may be a deep humming sound that waxes and wanes in a similar way.
While many people describe delirious swellings of body image, Devon B., when feverish, experienced mental or intellectual swellings instead:
What made them so strange was that they weren’t sensory hallucinations, but a hallucination of an abstract idea … a sudden dread of a very, very large and growing number (or a thing, but a thing I never really defined)…. I remember pacing up and down the hallway … in a growing state of panic and horror at an exponentially increasing, impossible number.…
My fear was that this number was violating some very basic precept of the world … an assumption we hold that absolutely should not be violated.
This letter made me think of the arithmetical deliria which Vladimir Nabokov went through, wrestling with impossibly large numbers, as he described in his autobiography
Speak, Memory:
As a little boy, I showed an abnormal aptitude for mathematics, which I completely lost in my singularly talentless youth. This gift played a horrible part in tussles with quinsy or scarlet fever, when I felt enormous spheres and huge numbers swell relentlessly in my aching brain.… I had read … about a certain Hindu calculator who in exactly two seconds could find the seventeenth root of, say, 3529471145760275132301897342055866171392 (I am not sure I have got this right; anyway the root was 212). Such were the monsters that thrived on my delirium, and the only way to prevent them from crowding me out of myself was to kill them by extracting their hearts. But they were far too strong, and I would sit up and laboriously form garbled sentences as I tried to explain things to my mother. Beneath my delirium she recognized sensations she had known herself, and her understanding would bring my expanding universe back to a Newtonian norm.