Читать книгу Concussion - Kester J Nedd DO - Страница 6
ОглавлениеPEOPLE WITH CONCUSSION and/or traumatic brain injury (TBI) and their loved ones know the reality of facing a radical change in an instant. Can you imagine being a fully functional human being, caring for your family, holding down a job, or performing as a student in school, then suddenly not being able to do any of these at a level you were previously able to perform?
Meet Mario (Case #1), a 24-year-old dental student from Venezuela, an avid sportsman who lived for the thrill and exhilaration that only a few experience while participating in extreme sports. Mario suffered a form of TBI that is rarely seen – second impact syndrome (SIS). I came across Mario and his family when they were desperately in search of a neurologist who had experience caring for individuals with severe TBI. About 10 days after suffering a cerebral concussion while wakeboarding, Mario returned to the sport while having persistent dizziness, vertigo (sensation of spinning), and headaches. He received medical care from a neurologist following his first cerebral concussion and was told that the CAT scan of his brain was normal, even though his condition was labeled as a cerebral concussion. Unfortunately, when he returned to the sport, he suffered a second injury as he was thrown off the wakeboard moving at a high speed. For the second time, his head impacted against the water, which when traveling at a high speed, feels equivalent to an impact against a brick wall. Mario’s friend lifted Mario out of the water and onto the boat, realizing he was limp and unable to help himself. His friend noted that he was minimally conscious but still breathing. On his way to the shore, Mario had a grand mal tonic-clonic seizure with intense violent jerking movements involving both sides of the body. When the paramedics arrived on the shore, he was intubated (a tube placed in his windpipe through his mouth) and placed on a ventilator – a device that facilitated his breathing. He was taken to a local hospital and the initial CAT scan of his brain showed diffuse cerebral edema (brain swelling) and a small right subdural hematoma (bleeding under the coverings of the brain). At the hospital, he was minimally responsive to pain, able to spontaneously move his extremities, but not able to communicate. Within a few hours of arrival at the hospital, he became totally unresponsive. His neurological exam showed a dilated pupil on the right eye. A dilated pupil that does not react to light especially on one side is usually indicative of compression of the third cranial nerve in the brain. The third cranial nerve is responsible for the contraction of the pupil when the eye is exposed to light. Further, a dilated pupil is generally an ominous sign of brain herniation from swelling or the effect of a mass, such as a subdural hematoma, causing the shifting of the brain from one side to the other. The effect of the edema and of the mass (subdural hematoma) also known as mass effect, caused the shift in Mario’s brain, which resulted in compression of the third nerve. Since this change was considered a neurological emergency, a follow-up CAT scan of the brain was carried out, which showed increased diffuse swelling of the brain with a shift of the brain from the right to the left, due to the massive expansion of the subdural hematoma on the right.
| Image # 1 – What Mario’s brain looked like before surgery |
Mario was taken into surgery, and a decompressive craniectomy (removal of a portion of the skull) was performed to drain the subdural hematoma and reduce the pressure in the brain. This gave the brain room to expand due to the swelling process, a sign of severe brain injury.
It was clear that Mario had SIS, a condition rarely diagnosed in TBI. But when diagnosed, SIS is most common in concussion and TBI due to sports-related injuries.
Despite having symptoms after the first injury, Mario was cleared by his neurologist to return to the sport. It was even more devastating that after a further review of the original CAT scan of the brain from his first injury, an area of contusion (brain bruise) in the right hemisphere of the brain was revealed. This area of contusion on the very first CAT scan was not picked up by the neurologist or the neuro-radiologist. As a result, he was cleared to return to the sport. Mario returned to wakeboarding before he had a chance to fully recover from the original injury, which along with the second injury caused his brain to suffer extreme swelling.
Mario’s brain injury was severe enough to result in a major disruption of his brain’s hierarchical organization, causing him to be in a comatose state for over one year. After six years of caring for Mario and observing the effects of TBI and concussion in many of my patients, while also; witnessing up close the natural history of how the nervous system recovers following injury, I was inspired to develop this work.
Imagine for one moment that the human brain has over 100 billion neurons (nerve cells) which create over 1,000 trillion connections. It is estimated that the brain, as a supercomputer, can process one trillion bits per second and has a memory capacity that can vary from one to one thousand terabytes of data. This extraordinary system has been compared with the Library of Congress, which has over 19 million volumes equivalent to 10 terabytes of data.
| Image # 2 – Neurons and their interconnections |
The complexity of such a system as it sits in our skull is unfathomable.
On a metaphysical level, it is an entire galaxy.
To paraphrase an expression, “It took years to build Rome, but it was destroyed in a day”. As a corollary, it took years for the human brain to evolve to its current state of sophistication and years following conception and birth to organize such a brain to perform what we now know as human behavior.
Yet, this highly organized structure can be destroyed in an instant!
