I’m brought back to a curtained area, patient spaces separated by curtains on tracks, like in an ER. Not a lot of privacy, but then the place is basically empty this early on a Monday morning. I’m given a gown to change into, leave it open in the back, and I lie down on the gurney, watching people walk purposefully past the undrawn curtains around my bed. The anesthesiologist returns with a tray of alarming-looking needles and another person, a medical resident, he says, introducing her. I’m momentarily alarmed: “Shouldn’t there be more people?” But no, he tells me. It’s a two-person job. And so they sit me up, my entire head a ball of pain, and the resident straps a rubber tourniquet around my arm and asks me to make a fist as the anesthesiologist swabs my lower back with something cold, then needles it in several places with lidocaine. Soon, the resident is extracting blood from my arm, blood that must be used immediately, and I am made to lean forward as the anesthesiologist hunts for the right spot to stab me in the back with a giant needle and deliver that blood.
“I can feel that,” I say at one point, as I lean on the resident’s chest and fight off the go-toward-the-light tunnel vision brought on by having my blood drawn and my back skewered, and the excruciating headache brought on by sitting up. “Some pressure?” the doctor asks. “No, the needle,” I say. “It’s just pressure,” he says. “It’s the needle, I can feel it,” I say. I start to pass out and they both yell questions at me to keep me awake. “How long have you lived here? What do you do? How many kids do you have? What did they do for you for Mother’s Day?” My arms are tingling and my brain feels like it’s getting smaller and smaller as I try to form words. Seventeen years, I can’t, I can’t, write books, I can’t, two, I can’t, I can’t, nothing, nothing, nothing, they didn’t do anything I can’t.
“How old are your kids?” The doctor asks me, and the irony of it finally hits me, my worry about this illness making me a bad mother, being caused by being a bad mother, by being weak. Dura mater is the full name of the thing that tore in me. It means “tough mother.”
They ask me to tell them when it’s too much pressure, and I cry as I feel the needle jabbing some nerve and a heaviness in my back and finally yes, it’s too much pressure, too much pressure in my back, too much pressure to be the one who has to decide how much pressure is too much pressure, to have it be my decision, my call, to have everything left up to me.
They lay me back onto the table and tell me I’m fine, that I did better than they’d expected (what had they expected?), and my headache is, for the moment, gone—but then it often subsides from lying down, so I can’t be sure it’s truly been banished. I’m foggy still, still unable to think like I used to be able to think, and exhausted from the blood pressure drop and the tears, and my back weeping what I hope isn’t blood, though I can see the floor dotted with it, smears and drops they haven’t bothered to clean up yet. I lie there on the cold table for an hour and then limp to the car to go home, my lower back and right leg a nerve map of pain. “You should be fine in a few days,” the doctor says before I leave. “If you’re not, we can do another one. Second blood patches have a success rate of over 95 percent.” I tell him that I hope I never have to have another blood patch ever again, but he just shrugs and smiles and says, “Well, let me know. It’s your call.”
Days after the procedure I am out of bed, my back heavy, my right leg twinging, because the doctor has called and told me to be out of bed, as I can tolerate it, and because I have noticed that now when I lie down, my headache—oh yes, even after this procedure, I still have a headache—becomes intolerable. This is normal, the doctor tells me, it is normal for my head to feel like a blown-up balloon, to feel pressure behind my eyes and nose, to feel the genuinely unpleasant sensation of something like a deadly python squeezing my brain. This version of the headache is the Opposite-Day version of what I’ve been experiencing up until now: It used to be low, infiltrating the base of my skull; now it’s high, in the front of my face. It used to improve a little when I lay flat; now lying flat makes me feel as though my head is about to explode. Caffeine used to make me feel better; now it makes the headache pain worse. “This happens sometimes,” the doctor tells me over the phone. “Give it a few days to settle, give it time.” I move slowly, but I move, and I try to stay upright instead of flat, and I try to drink less caffeine, and I try to give it time, because the doctor tells me this thing he’s done is the thing that will fix me, so I must be fixed, right?
“How will I know if I need another patch? How will I know if this one doesn’t work?” I ask him, and he says it’s too early to tell. My head is now a balloon, ready to pop, and the headache is everywhere, and I am giving it time, but time seems to be colluding with the mystery of this thing to draw out the suspense. I wait for it all to settle as I grapple with the new contours of my pain, trying to ignore the dread that settles in instead that even though I am supposed to be fixed, I am not fixed, and perhaps not fixable.
10
All of us have a kind of primordial ocean in our heads, keeping our brains aloft on its current. This ocean of cerebrospinal fluid is generated continuously in the depths of our brains, produced by the choroid plexuses within the third and fourth ventricles. It suffuses and surrounds our brains, providing buoyancy, and bathes our spinal cords, lubricating the entirety of the central nervous system. Like the deep ocean, much of this has been nearly impossible to observe firsthand. The history of cerebrospinal fluid has been centuries of murky guesswork, increasingly deeper dives, usually by solo divers, revealing glimpses of an alien landscape, the dark waters of a humanoid ocean floor patrolled by impossible creatures, the hulls of failed ships transformed into coral reefs, nature reclaiming its space.
There is cerebrospinal fluid within us before we even technically have either a brain or a spine. It comes before thought, before mind, before brain, before even the development of those choroid plexuses in the ventricles of the brain that will eventually take over the process of circulating and generating this fluid, before any of us are recognizable as human. It exists in three-week-old embryos in the form of fluid within the neural tube that will eventually become the brain and central nervous system; by the fourth week, the first choroid plexus, a network of blood vessels and cells, develops in the fourth ventricle. Eventually this structure begins to produce and release cerebrospinal fluid continuously, as it will for the rest of our lives.
This isn’t a thing that we can consciously control. Like the deep ocean, it is its own mystery. There are tides to cerebrospinal fluid production, peaks in its manufacture during the day and night to which none of us will ever likely be sensitive, unless something, mysteriously, goes wrong. Like the deep ocean, it used to be thought that this water in our brains was just water, and not something teeming with life, with its own purpose. And yet, like the deep ocean, it has also been the subject of myths and legends, with speculation about its mystical properties, assertions that this magical fluid might actually be the river of life, the source of consciousness, the place where the soul resides. We understand more now about the anatomy and structure and purpose of the brain and central nervous system; we have a more fleshed-out understanding than we did in the days where notions of these things were like maritime maps with drawings of dragons and mermaids and other fantastical creatures to mark spots of danger and obscurity. But in some ways the reality of what lies in its depths is stranger than anything we imagined; like the ocean, no dragons or mermaids, but instead merely the weirdness of furry-clawed crabs living 5,000 feet deep in hydrothermal vents, blind lobsters, light-producing deep-sea anglerfish, giant squid, bioluminescent octopi, isopod crustaceans, and other creatures that have been inhabiting this world, unbeknownst to us, for longer than humans have existed. It’s only recently that we have learned there’s more to cerebrospinal fluid than just providing a cushion to our brains, allowing them to float, acting as a link to our distant, primeval beginnings of life in the sea billions of years ago.
The earliest documentation of
cranial cerebrospinal fluid was discovered on a papyrus fragment found in 1862 by the Egyptologist Edwin Smith. When the papyrus was finally translated in the 1930s, it revealed a medical history written by the Egyptian physician Imhotep around 3000 BC, detailing an account of a patient with open head trauma. According to Imhotep’s report, the patient’s skull fracture and meningeal rupture “[broke] open his fluid in the interior of his head.”
Other ancient physicians observed this brain fluid but did not always agree about its purpose—or even its existence. While Hippocrates (460–375 BC) described “water” surrounding the brain, the anatomist Galen (AD 130–200) noted the presence of “excremental liquid” in the ventricles of the brain, but dismissed it, believing those cavities to primarily contain not fluid but a gas-like spiritus animalis that provided energy throughout the body and was the key to human consciousness.
Andreas Vesalius, a sixteenth-century anatomist from the Netherlands considered the founder of modern human anatomy, described the cerebral ventricles and choroid plexus, and noted the presence of “brain water,” estimating that its volume was as much as one-sixth the volume of the brain. (Modern MRI studies have revealed that cerebrospinal fluid accounts for 18 percent of total brain volume.) He also, strikingly, broke with the Aristotelian tradition of believing the heart to be the center of the soul, and the source of feelings and emotions in the body: He posited that the brain and nervous system was where the mind was, and was the originator of emotion, and made the bold claim that nerves originate from the brain, and not the heart. (He also put to rest the medical belief put forth by Galen that women have fewer teeth than men.)
The Venetian physician Nicolò Massa noted in his 1536 publication Anatomiae Libri Introductorius that there appeared to be fluid within cerebral ventricles. More than one hundred years later, Humphrey Ridley published the first English-language manuscript about brain anatomy, which also made note of the presence of cerebrospinal fluid within the ventricles. The anatomist Antonio Maria Valsalva, whose name we know from his eponymous maneuver, and whose primary interest was the workings of the human ear, in 1692 described cerebrospinal fluid as existing within the subarachnoid space around the spinal cord.
In Italy in the 1700s, Domenico Cotugno literally turned on its head the then-traditional method of performing autopsies (severing the head from the rest of the body before dissecting the brain), by instead keeping the bodies intact and positioning them upside down. This allowed him to observe fluid beneath the dura mater, the tough covering surrounding the brain and spinal cord, and within the ventricles of the brain. For a time, due to his discovery, cerebrospinal fluid was called “liquor Cotunnii,” or Cotugno’s liquid. Still, it wasn’t until 1842 that the French physician François Magendie coined the term “cerebrospinal fluid” and discovered a means of measuring its pressure, laying the foundation for the development of cerebrospinal fluid dynamic research. And yet even then Magendie’s contemporaries, including neurologists Albert von Haller and Moritz Romberg, argued that the brain’s networked series of cavities—the ventricles—were filled with some kind of humid gas instead of fluid.
Working in isolation, somewhat outside of the medical profession, was a Swedish engineer turned anatomist turned theologian named Emanuel Swedenborg, who between 1741 and 1744 came up with a visionary description of cerebrospinal fluid that wasn’t widely recognized until his work on the subject was published posthumously in 1887. His insights into cerebrospinal fluid and the cerebral cortex coincided with a time in his life when he experienced a spiritual awakening that led him to believe he had been appointed by Jesus Christ to reform Christianity, starting a religious movement that continues to this day. Somehow, along the way, he managed to investigate the mysteries of CSF, referring to it as “spiritous lymph” and “highly gifted juice.” In a kind of fluid-filled echo of the ancient conclusions Galen held about the gaseous animal spirits of human consciousness residing in the pockets of the brain, Swedenborg believed the cerebrospinal fluid to be where the soul resides. Swedenborg also greatly influenced Andrew Taylor Still, the founder of osteopathy (a branch of medicine concerned with managing health through the manipulation of bones, joints, and muscles). Both Still and Swedenborg believed in the idea of cerebrospinal fluid as the location of the soul, and vital to overall health. As Still put it: “The cerebrospinal fluid is the highest known element in the human body. He who is able to reason will see that this great river of life must be tapped and the withering field irrigated at once or the harvest of health is forever lost.” Other osteopaths, such as Randolph Stone, who went on to found something he called polarity therapy—a kind of holistic energy healing practice—also characterized CSF as a spiritual “liquid medium for . . . life energy radiation, expansion, and contraction.” Stone said, “Where this is present, there is life and healing with normal function. Where this primary and essential life force is not acting in the body, there is obstruction, spasm, or stagnation and pain, like gears which clash instead of meshing in their operation.” Even modern-day naturopaths such as New Mexico doctor Robert Stevens subscribe to this view of cerebrospinal fluid as something spiritual and holy: “On the physical level, cerebrospinal fluid becomes the physical carrier of the wisdom of the Soul. This fluid conveys the sound and light energies of the Soul throughout the physical body. CSF expresses this highest vibratory rate and intelligence to the whole physical body.”
Outside of the community of visionaries and spiritual osteopaths, for hundreds of years the consensus was, among most physicians, that the primary function of cerebrospinal fluid was to protect and cushion the brain. It took until the early twentieth century for cerebrospinal fluid to be recognized as playing a crucial role in the function of the entire central nervous system. Harvey Cushing, the father of neurosurgery, called this the “third circulation” in a 1925 paper that established CSF physiology as a crucial aspect of neuroscience. He saw the flow of cerebrospinal fluid as a circulatory system similar to vascular and lymphatic circulation, and introduced the idea of cerebrospinal fluid and its circulation as a kind of lymphatic system for the brain, clearing out waste. He suggested that cerebrospinal fluid flows through the ventricles, cisterns, and subarachnoid space, and is reabsorbed into the blood at the arachnoid villi—from arachne, meaning spider, and villus, shaggy hair, these are spidery, hair-like projections of fibrous tissue protruding from the arachnoid membrane.
There are three membranes surrounding the brain and spinal cord, collectively known as the meninges, and the dura mater is the outermost of the three. These membranes—the pia mater (tender mother, attached to the surface of the brain and spinal cord), the arachnoid mater (spider-like mother, the middle layer, named for its spiderweb appearance), and the dura mater (tough mother, named for its durability and strength)—protect the central nervous system. The dura is, true to its name, normally a quite dense and fibrous connective tissue, which functions somewhat like a sac encapsulating the brain and spinal cord, extending to the sacrum, beyond the base of the spinal cord.
It’s the dura that keeps the cerebrospinal fluid contained. The fluid moves within it, pulsing from the inner recesses of the brain, and traveling along the length of the spinal cord, coating the entire central nervous system. When the dura mater is pierced or torn from trauma or injury or medical procedures gone wrong, cerebrospinal fluid can seep out, reducing the pressure of the rest of the fluid around the brain. Often the only sign that this has happened is a headache that becomes worse when sitting or standing, as being upright reduces the pressure around the brain even more. Women in labor who receive epidural anesthesia, where a needle is used to inject anesthetic into the space just outside the dura, can experience this if the anesthesiologist pushes the needle just slightly too far, piercing the dura. People requiring spinal injections, where a needle is deliberately inserted through the dura to deliver anesthetic, or lumbar punctures are also at risk. Often these small holes, made by very fine needles, repair themselves or otherwise seal over a
nd resolve over days or weeks; when they do not, intervention is required. Instances like these, where the site of the leak is known, are more straightforward to address; spontaneous cerebrospinal fluid leaks—those not caused by deliberate or accidental needle puncture—are harder to track down, more difficult to source, and thus trickier to repair.
The first case of post-lumbar puncture headache was noted in the nineteenth century. In the early part of the twentieth century, doctors began documenting cases involving patients suffering from symptoms resembling that of a post-puncture headache, but without the puncture. These low CSF volume headaches came to be known as spontaneous intracranial hypotension, or spontaneous spinal CSF leaks. The condition became more recognized throughout the latter half of the twentieth century through pioneering work by neurologists like the late Bahram Mokri, who spent much of his forty years at the Mayo Clinic researching and treating cerebrospinal fluid leaks; but even today a solid body of research on the subject is only just beginning to emerge. This makes it an exciting time for researchers, as nearly any new data about spinal CSF leaks breaks new ground, medically speaking; and a frustrating time for clinicians, as there is little in the way of hard facts to offer patients in terms of prognosis and recovery. The team of doctors at Cedars-Sinai in Los Angeles, including neurosurgeon Wouter I. Schievink, and the team of doctors at Duke University, including neuroradiologists Linda Gray-Leithe and Peter Kranz, are the current top clinician-researchers in the field, pushing for and performing valuable research, inventing and refining pioneering treatments, mentoring other physicians in the diagnosis and management of cerebrospinal fluid leaks, and learning from the patients they treat.
The history of evolving medical knowledge of cerebrospinal fluid—its importance, its function, the problems that emerge when the system it’s a part of becomes compromised or otherwise out of balance—is one of independent discoveries, sometimes the same discoveries made by different people at different times in different parts of the world. Even now, the challenge is to disseminate basic facts and protocols for treatment among doctors of different specialties, so that this obscure body of knowledge can be more widely shared, and offer patients better avenues toward treatment. It is somewhat telling that the first major symposium on spontaneous intracranial hypotension to take place anywhere in the world, bringing together researchers, neurologists, primary care doctors, nurses, physical therapists, other medical professionals, and patients, happened only as recently as October 2017.
The Beginning of Everything Page 4