Looking at a picture of the brain on Google images, you’d probably assume it’s solid and dense. At least that’s what I used to think. Yet, contrary to its outer appearance, the inside of the brain consists of multiple seemingly empty cavities that are connected via tunnels. These regions, called ventricles, hold fluid that prevents the brain from collapsing from its own weight. This fluid, cerebrospinal fluid (CSF), flows through the cavity-tunnel system, then out and around the brain. However, when the tunnels comprising this system become occluded, CSF flow becomes backed up, and the fluid begins to accumulate. This phenomenon, called hydrocephalus, quickly becomes very dangerous. Excess CSF physically pushes on brain tissue thereby killing neurons. While scientists today understand hydrocephalus, arriving at this point required many years of studying and failed treatment attempts.
The first documentation of hydrocephalus traces back to Hippocrates, who called it “water on the brain”. At this time, no one knew where the “water” came from, or if it served a functional role within a healthy brain. This created space for many hypotheses and treatment strategies. For instance, some physicians wrapped patient’s heads tightly to prevent the skull from expanding. Other’s believed applying oils to the skull was the optimal treatment. Interestingly, in the seventeenth century, Dutch physician Isbrand Diemerbroeck believed that improper nutrition was causing hydrocephalus in children. He speculated that an unhealthy diet led to an overproduction of fluids within the intestinal tract. Then, once accumulated, Diemerbroeck thought these products left the digestive system, traversed to the skull, and caused hydrocephalus. He recommended that patients be treated with laxatives and altered diets to modulate symptoms. However, the startlingly high mortality rates from each of these intervention methods displayed their ineffectiveness. Fortunately, everything changed upon the work of Swiss physician Albrecht von Haller.
While many scientists contributed to our current understanding of CSF and its relation to hydrocephalus, Haller played a key role. In 1747, he noticed that the “water” was present both on the surface of the brain and within. He then proposed that this fluid was secreted into the brain by arteries and reabsorbed by the venous system. Further, he believed that hydrocephalus was caused by too much fluid secretion from the arterial system. This hypothesis, while lacking some important details, was somewhat accurate. It sparked additional research into CSF and led to the development of newer treatments that had higher success rates. Eventually physicians shifted entirely away from oils, head wrappings, and diet, to modernized procedures used today.
Currently there are two approaches to treating hydrocephalus. The first being shunts. These long, thin tubes act as a re-directing route for CSF flow. One end of the tubing is surgically placed within a ventricle. The tubing is then channeled below the skin to the abdomen. The abdomen is capable of absorbing and removing excess fluid, making it perfect for CSF dumping. These shunting systems are generally in place throughout the duration of a patient’s life. Unlike the lifelong maintenance of a tubing system, the second treatment method consists of a singular surgery called an endoscopic third ventriculostomy. While certainly a mouthful to say, this procedure consists of creating a hole in one of the ventricles to allow for more efficient CSF flow.
Hydrocephalus is largely survivable today. However, this wasn’t the case for many years. Without any real knowledge of CSF and its flow within and around the brain, physicians were left grasping at straws for treatments. At the time, interventions ranged from applying oils and wrapping heads, to consuming laxatives. Now, many years and experiments later, scientists have a better understanding of CSF and its flow. This allowed for the development of highly successful treatment strategies for water on the brain.
King Lab at Creighton University 