Nervous Case Study 5 - Split My Brain*
Jerrod Hamilton is seven years old. Jerrod has always been a very active boy. He loves hockey, baseball, swimming at the local pool, and climbing trees. He also does fairly well in school, although he is not as interested in the classroom as he is in recess.
Shortly before Jerrod’s seventh birthday, he had a small seizure. His right arm twitched a little and he seemed disoriented for a few seconds. Afterward he said he was fine. Soon he had another couple of episodes of muscle twitching and weakness. During these seizures, Jerrod also stared blankly, moving his head slightly back and forth, and for a minute or two could not respond to his parents. When the seizures ended, Jerrod had no memory of them.
Jerrod’s parents took him to their pediatrician, Dr. Madeline Sierra, who listened as Jerrod’s parents described his symptoms.
“Before I try to conclude anything, I’d like to order several tests for Jerrod, including an EEG and an MRI scan. I know that sounds a little scary, but the tests are painless and noninvasive. We should get the results back very quickly. Once I see those, I’ll know more about what’s going on.”
Jerrod’s tests were done right away, and his parents met again with Dr. Sierra. Jerrod’s symptoms were escalating. He had daily seizures, and they included disorientation as well as uncontrollable repetitive movements on the right side of his body. He often felt tired and weak after the seizures.
“Now, I want you to know I’m not abandoning you on this. I’ll be following Jerrod carefully, too. But I don’t think we should take any chances with this little guy.” She smiled and ruffled Jerrod’s hair.
Dr. Sierra’s referral sent Jerrod and his parents to a neurologist
who specialized in seizure disorders, Dr. Benjamin Singh.
“Here is the output from Jerrod’s EEG exam.” Dr. Singh showed them a printout. “This test shows us the level of electrical activity in Jerrod’s brain. There is a particular pattern of spikes here that shows his seizure activity. Based on these tests and some other indications, I believe Jerrod’s seizures are what we call ‘partial’ seizures. This means that they only involve part of the brain. And right now, his MRI scan is okay.”
Jerrod’s parents looked at each other with some relief.
Dr. Singh prescribed medication to help treat Jerrod’s disorder. The first medication didn’t succeed, so Dr. Singh and Dr. Sierra conferred and then tried another. After some time and other combinations of medications, it became clear that this type of treatment would be problematic for Jerrod.
Jerrod’s father asked, “What is going on? Why don’t the medicines work? You’ve said there’s no injury or tumor. So, is this a condition he inherited from us somehow? Or is it an allergic reaction to something?”
“No,” Dr. Singh reassured them. “Most likely none of those things are causing Jerrod’s problem. This is also not your fault or Jerrod’s fault. I believe that Jerrod has a disorder called Rasmussen Syndrome. Unfortunately, we don’t know what causes it. Some people suspect it may be some type of viral infection, but we don’t know for sure. So, likely there is nothing you could have done to prevent it. It involves the type and frequency of seizures we are seeing in Jerrod and usually occurs in children of about Jerrod’s age. I must warn you that it is a progressive and potentially serious illness that often does not respond to medication.”
Dr. Singh went on to describe another type of more drastic treatment that might work in Jerrod’s case.
“In Jerrod’s case, his seizure activity is located primarily in the left hemisphere of his brain. Sometimes, we can control or even eliminate seizure activity by removing the portion of the brain which is suffering. We call this a functional hemispherectomy.”
“What do you mean, ‘removing’? You take out his brain?” Jerrod’s mother was horrified.
“Not his entire brain, just the parts that show abnormal activity. In Jerrod’s brain, that would mean a large part of his left hemisphere. We would remove Jerrod’s left temporal lobe, part of his left frontal lobe, and perhaps some areas in his parietal and occipital lobes. We would also sever the corpus collosum, the band of tissue that connects the two hemispheres and allows them to communicate. We would leave intact Jerrod’s thalamus, amygdala, hippocampus, and other deep structures of the brain.”
Dr. Singh looked at their worried faces. “It sounds terrible, but there have been quite a number of these surgeries performed. Believe it or not, and I know it is difficult to believe, this may be our best option.”
Describe how a nerve impulse is transmitted from one neuron to the next.
2. What is myelin? What is its function? Explain
3. Compare and contrast the structure and functions of the Central Nervous System and the Peripheral Nervous System. How are nerve cells ensheathed with myelin in the CNS? In the PNS?
4. What are the procedures for doing an EEG test and MRI scan? What type of information does each of these tests provide? (See http://www.epilepsy.com/articles/ar_1066258237.html and http://www.epilepsy.com/articles/ar_1066257900.html.)
What is epilepsy? How is it diagnosed?
6. Based on the information in the case, what type of seizures does Jerrod appear to be having?
7. What should you do during a seizure to help Jerrod?
8. What are some treatments for epilepsy?
9. What is Rasmussen Syndrome (what are its history, symptoms, prognosis, etc.)?
10. What structures or abilities of the brain are concentrated in the areas of the left hemisphere that would be removed in the hemispherectomy?
11. Other than reducing his seizures, how else might Jerrod’s thinking or behavior be affected by losing these parts of his brain?
12. What types of abilities would he still retain, because the brain structures would remain intact?
*adapted from “Split My Brain” by Julia Omarzu, Dept of Psychology, Loras College, Dubuque, Iowa