Hallucinations (16 page)

One has to call these hallucinations, even though they are only patterns and not images, for there is nothing in the external world that corresponds to the zigzags and checkerboards—they are generated by the brain. And there may also be startling perceptual changes with migraine. I might sometimes lose the sense of color or of depth (for other people, color or depth may intensify). Losing the sense of movement was especially startling, for instead of continuous movement, I would see only a stuttering series of “stills.” Objects might change size or shape or distance, or get misplaced in the visual field so that, for a minute or two, the whole visual world would be unintelligible.

There are many variations on the visual experiences of migraine. Jesse R. wrote to me that during a migraine, “I think
my mind loses its ability to read shapes and misinterprets them.… I think I see a person instead of the coat rack … or I often think I see movement across a table or floor. What is strange is that the mind always errs toward giving life to inanimate objects.”

Toni P. wrote that before her migraines, she might see alternating black and white zigzag lines in her peripheral vision: “shiny geometric shapes, flashes of light. Sometimes it is as if whatever I am viewing is through a sheer curtain that is blowing in the wind.” But sometimes, for her, a scotoma is simply a blank spot, producing an uncanny sense of nothingness:

Another woman, Deborah D., had an attack of migraine in which, she wrote:

It is not only the visual world that may be affected in a migraine aura. There may be hallucinations of body image—the feeling that one is taller or shorter, that one limb has shrunk
or grown gigantic, that one’s body is tilted at an angle, and so forth.

It is known that Lewis Carroll had classical migraines, and it has been suggested (by Caro W. Lippman and others) that his migraine experiences may have inspired Alice in Wonderland’s strange alterations of size and shape. Siri Hustvedt, in a
New York Times
blog, described her own transcendent Alice-in-Wonderland syndrome:

There may be auditory misperceptions and hallucinations in migraine: sounds are amplified, reverberant, distorted; occasionally voices or music are heard. Time itself may seem distorted.

Hallucinations of smell are not uncommon—the smells are often intense, unpleasant, strangely familiar, yet unspecifiable. I myself twice hallucinated a smell before a migraine, but a pleasant one—the smell of buttered toast. The first time it happened, I was at the hospital and went in search of the toast—it did not occur to me that I was having a hallucination until the visual fortifications started up, a few minutes later. On both occasions there was a memory or pseudomemory of being a little boy in a high chair about to have buttered
toast at teatime. One migraineur wrote to me, “I have always smelled beef roasting about thirty minutes before the onset of a migraine.”
²
A patient described by G. N. Fuller and R. J. Guiloff had “vivid olfactory hallucinations, lasting five minutes, of either her grandfather’s cigars or peanut butter.”

W
hen I worked in a migraine clinic as a young neurologist, I made a point of asking every patient about such experiences. They were usually relieved that I asked, for people are afraid to mention hallucinations, fearing that they will be seen as psychotic. Many of my patients habitually saw patterns in their migraine auras, and a few had a host of other strange visual phenomena, including distortion of faces or objects melting or flickering into one another; multiplication of objects or figures; or persistence or recurrence of visual images.

Most migraine auras remain at the level of elementary hallucinations: phosphenes, fortifications, and geometrical figures of other sorts—but more complex hallucinations, though rare in migraine, do occur. My colleague Mark Green, a neurologist, described to me how one of his patients had the same vision in every migraine attack: a hallucination of a worker emerging from a manhole in the street, wearing a white hard hat with an American flag painted on it.

S. A. Kinnier Wilson, in his encyclopedic
Neurology
, described
how a friend of his would always have a stereotyped hallucination as part of a migraine aura:

Klaus Podoll and Derek Robinson, in their beautifully illustrated monograph
Migraine Art
, have collected many reports of complex hallucinations in migraine from the world literature. People may see human figures, animals, faces, objects, or landscapes—often multiplied. One man reported seeing “a fly’s eye made of millions of light-blue Mickey Mouses” during a migraine attack, but this hallucination was confined to the temporarily blind half of his visual field. Another saw a “crowd of [more than] one hundred people, some dressed in white.”

There may also be lexical hallucinations. Podoll and Robinson cite a case from the nineteenth-century literature:

Lilliputian hallucinations can occur in migraine (as well as in other conditions), as Siri Hustvedt described in a
New York Times
blog:

All of these effects seem to show, by default, what a colossal and complicated achievement normal vision is, as the brain constructs a visual world in which color and movement and size and form and stability are all seamlessly meshed and integrated. I came to regard my own migraine experiences as a sort of spontaneous (and fortunately reversible) experiment of nature, a window into the nervous system—and I think this was one reason I decided to become a neurologist.

W
hat is stirring up the visual system during a migraine attack, to provoke such hallucinations? William Gowers, writing more than a century ago, when little was known of the cellular details of the visual cortex (or the brain’s electrical activity), addressed this question in
The Border-land of Epilepsy:

Gowers’s intuition proved quite accurate and was given physiological backing decades later, when it was discovered that a wave of electrical excitation could track across the cerebral cortex at much the same rate the fortifications did. In 1971, Whitman Richards suggested that the zigzag shape of migraine fortification patterns, with its characteristic angles, might reflect something equally constant in the architecture of the visual cortex itself—perhaps clusters of the orientation-sensitive neurons which Hubel and Wiesel had demonstrated in the early 1960s. As the wave of electrical excitation slowly marches across the cortex, Richards suggested, it might directly stimulate these clusters, causing the patient to “see” shimmering bars of light at different angles. But it was only with the use of magnetoencephalography, twenty years later, that it was possible to demonstrate that the passage of fortifications in a migraine aura was indeed accompanied by just such a wave of electrical excitation.

A hundred and fifty years ago, the astronomer Hubert Airy (who was a migraineur himself) felt that the aura of migraine provided “a sort of photograph” of the brain in action. He, like Gowers, may have been more literally accurate than he knew.

H
einrich Klüver, writing about mescal, remarked that the simple geometric hallucinations one might get with hallucinogenic drugs were identical to those found in migraine and many other conditions. Such geometrical forms, he felt,
were not dependent on memory or personal experience or desire or imagination; they were built into the very architecture of the brain’s visual systems.

But while the zigzag fortification patterns are highly stereotyped and can perhaps be understood in terms of the orientation receptors in the primary visual cortex, a different sort of explanation must be sought for the rapidly changing, permuting play of geometric forms. Here we need dynamic explanations, a consideration of the ways in which the activity of millions of nerve cells can produce complex and ever-changing patterns. We can actually see, through such hallucinations, something of the dynamics of a large population of living nerve cells and, in particular, the role of self-organization in allowing complex patterns of activity to emerge. Such activity operates at a basic cellular level, far beneath the level of personal experience. The hallucinatory forms are, in this way, physiological universals of human experience.

Perhaps such experiences are at the root of our human obsession with pattern and the fact that geometrical patterns find their way into our decorative arts. As a child, I was fascinated by the patterns in our house—the square colored floor tiles on the front porch, the small hexagonal ones in the kitchen, the herringbone pattern on the curtains in my room, the check pattern on my father’s suit. When I was taken to the synagogue for services, I was more interested in the mosaics of tiny tiles on the floor than in the religious liturgy. And I loved the pair of antique Chinese cabinets in our drawing room, for embossed on their lacquered surfaces were designs of wonderful intricacy on different scales, patterns nested within patterns, all surrounded by clusters of tendrils and leaves. These geometric and scrolling motifs seemed somehow familiar to me, though
it did not dawn on me until years later that this was because I had seen them in my own head, that these patterns resonated with my own inner experience of the intricate tilings and swirls of migraine.

Migraine-like patterns, indeed, can be found in Islamic art, in classical and medieval motifs, in Zapotec architecture, in the bark paintings of Aboriginal artists in Australia, in Acoma pottery, in Swazi basketry—in virtually every culture, going back tens of thousands of years. There seems to have been, throughout human history, a need to externalize and make art from these internal experiences, from the cross-hatchings of prehistoric cave paintings to the swirling psychedelic art of the 1960s. Do the arabesques and hexagons in our own minds, built into our brain organization, provide us with our first intimations of formal beauty?

There is an increasing feeling among neuroscientists that self-organizing activity in vast populations of visual neurons is a prerequisite of visual perception—that this is how seeing begins. Spontaneous self-organization is not restricted to living systems; one may see it in the formation of snow crystals, in the roilings and eddies of turbulent water, in certain oscillating chemical reactions. Here, too, self-organization can produce geometries and patterns in space and time very similar to what one may see in a migraine aura. In this sense, the geometrical hallucinations of migraine allow us to experience in ourselves not only a universal of neural functioning but a universal of nature itself.