Case Study

Part I

The brain is made of billions of individual cells called neurons. And they communicate through electrical signals known as action potentials. When a neuron experiences a change in electrical voltage that exceeds a certain threshold value, it shoots an electrical signal that propagates down the length of the cell body. At the gap between one neuron and the next, the electrical signal will cause chemicals known as neurotransmitters to be released. These chemicals activate an action potential in the adjacent neuron. And so on. Thus, electrical signals travel throughout the brain.

During a seizure, clusters of neurons send out the wrong signal. A group of neurons will collectively fire action potentials at once, but without any purpose. There are many types of seizures, but the most common feature of a seizure is a wave of uncontrolled electrical signals spreading throughout the brain. Seizures cause people to have strange emotions, behaviors, or muscle movements. They may also lose consciousness, and there is a possibility of the neurons being damaged.

Epilepsy is a condition where people have repeated seizures. It is usually diagnosed after a person experiences two or more seizures. For it to be diagnosed, you have to meet with a neurologist and go through some basic tests. You will review your medical history, describe your seizures, and go through some neurological examination. Usually, this examination is an EEG (electroencephalogram) test or a MRI (magnetic resonance imaging) test.

To take an EEG test, an EEG technologist will lightly glue several electrodes to your head. You will be led to a dark, quiet room, and asked to do things like move your eyes, look at lights, breathe, fall asleep, etc. The EEG test shows either normal or abnormal patterns of brain electrical activity. The results look like a bunch of horizontal, squiggly lines. These are electrical readings from different electrode locations. Certain patterns, known as “epileptiform abnormalities”, may indicate epilepsy. The EEG can also determine where in the brain the seizures are taking place, or whether the seizure is spread over the entire brain.

To take an MRI test, you may be given an intravenous injection. You will have to lie still underneath a large, noisy magnet that causes certain protons in your blood to spin differently. A sensor picks this up and uses it to create a detailed 3-d image of the fluid brain. MRI images can show changes in the brain structure, and some of these changes are associated with epilepsy. The MRI might show a brain tumor, an abnormal blood vessel, malformations of the development of the cortex (front of the brain), sclerosis (hardening of the brain tissue), or previous injuries (such as trauma, inflammation). This also provides information as to the potential effectiveness of surgery, since some things like sclerosis are easier to operate on than other things like malformations of cortical development.

There are a few possible causes of seizures other than epilepsy. Non-epileptic seizures are not caused by increased or abnormal electrical activity in the brain. Psychogenic seizures, or “pseudoseizures”, are caused by subconscious emotions or stress, and they are mostly psychological. EEG is the best way to tell whether a seizure is epileptic or psychogenic. Sometimes, other factors like brain injuries, tumors, and drugs can cause seizures that don’t qualify as epileptic seizures.

Jerrod may be having complex absence seizures. During complex absence seizures, a person will stare into space for up to 20 seconds, while making other movements like blinking or hand twitching. The best way to deduce what types of seizures he’s having is to wait for the EEG and MRI test results, which are usually more revealing than outward symptoms. If Jerrod has a seizure, it is important to stay calm and reassure people who are nearby. Speak calmly to Jerrod, clear the area of hazardous materials, but do not hold him down to stop him from moving. Time the seizure with a stopwatch, and act friendly as he regains consciousness. Call 911 if the seizure lasts longer than 5 minutes.

Epilepsy is generally treated with a variety of anti-seizure medications. Medicines can control seizures in about 7 out of 10 patients. Most people need to try more than one medicine. Some medicines act on neurons, and others affect neurotransmitters. If medicine does not have its intended effect, surgery, dietary therapy, and implantable devices are other potential treatment options.

Part II

Rasmussen’s Syndrome is a rare, chronic condition usually found in a single hemisphere of the brain. It is named after Theodore Rasmussen, a Canadian neurosurgeon. Some symptoms are: frequent and severe seizures, loss of motor skills and speech, paralysis on one side of the body, inflammation of the brain, and mental deterioration. The seizures often result in scarring and damaging of the brain tissue. The disease is caused when immune system cells enter the brain and cause inflammation. The reason for this inflammation is not known. The prognosis for Rasmussen’s patients varies, as no medical treatment has been shown to fully halt the progress of the disease. Most Rasmussen’s patients experience some paralysis and neurological deficits (especially cognitive and speech-related).

In diagnosing Rasmussen’s syndrome, EEG tests will show electrical epileptic waves and slower brain activity in the affected hemisphere. MRI tests will show shrinkage of the affected hemisphere, as well as inflammation or scarring. With Jerrod, both of these tests did indicate Rasmussen’s was a possibility. In his EEG, only certain areas of the brain showed seizure activity (this is the reason why his seizures are labeled as “partial” seizures). In his MRI, there were signs of scarring and shrinkage in the left hemisphere. The MRI showed that repeated seizures have started to damage his brain tissue.

A hemispherectomy would affect Jerrod’s left temporal lobe, part of his left frontal lobe, some of the parietal and occipital lobes, and the corpus collosum. These areas of the brain are involved in a variety of different tasks, and many of tasks revolve around cognition, communication, speech, etc. The left temporal lobe is involved with speech and vision processing, speech comprehension, and verbal memory. The frontal lobe is involved with cognition, decision making, consequences, and long-term emotional memories. The parietal lobe is involved with language processing, sensory information, and spatial recognition. The occipital lobe is involved with processing space, color, and motion. All four of these lobes are interconnected, and they are all part of the cerebral cortex. The corpus collosum connects the left and right hemispheres, and is involved with the coordination of activities that use both sides of the body.

Jerrod’s visual, motor, and cognitive function may be negatively impaired. He may have difficulty forming words with his mouth or processing speech. However, there are many arguments in favor of doing a hemispherectomy. First and foremost, Jerrod is likely to stop having seizures. 65% of Rasmussen’s patients are seizure free after surgery. But also, if Jerrod underwent a hemispherectomy, he would still retain certain abilities in undamaged parts of the brain. A hemispherectomy would not touch his thalamus, amygdala, hippocampus, brain stem, or basal ganglia. These are known as deep brain structures. The thalamus relays signals to the cortex and regulates consciousness. The amygdala processes memory, emotions, and decision-making. The hippocampus is located beneath the cerebral cortex and processes memory. The brain stem controls basic involuntary actions, like heart rate, breathing, and sleeping. The basal ganglia play a role in various functions including motor movements and procedural learning.

The whole family can help by creating a very supportive environment to minimize Jerrod’s stress as he recovers from surgery. It is likely that he might have a post-operational fever, but most of these fevers are harmless. It is also helpful to be around Jerrod while he goes through physical therapy, occupational therapy, and speech therapy.

Jerrod’s level of functioning might be negatively impacted in the short term, but it will likely make recoveries in the long term. Many hemispherectomy patients have difficulties with speech immediately after the surgery. It takes a certain measure of time (months or years) and rehab for patients to become accustomed to speaking again, but their brains do adapt by increasing the size of the speech centers in the undamaged hemisphere. In addition, all hemispherectomy patients have partial paralysis on one side of the body, but a great majority of them have adapted and regained the coordination necessary to do complicated activities like dancing. After rehab, Jerrod will likely be able to walk with a slight limp or a small ankle brace. He might lose some sensations in his right hand, however. Also, Jerrod most likely won’t experience an intellectual disability afterwards. In fact, neurosurgeons have shown that a patient’s IQ generally goes up after a hemispherectomy.

I personally would recommend going through with the surgery. There are many risks, and you as a family must be prepared for a long road back to recovery, but the benefits do outweigh the costs. As you have discovered, medicinal treatments are not likely to help with Rasmussen’s syndrome. More conservative surgical options are not likely to help either. And these seizures cannot be allowed to continue, as we don’t want Jerrod’s motor and intellectual abilities to gradually deteriorate. If Jerrod keeps having more and more intense seizures, not only will his left hemisphere be permanently damaged, but it might affect his right hemisphere too. He is still young, and his condition will only get worse with time, so now is the best time to act swiftly and end the seizures. As former patients have shown, it is possible to regain a considerable amount of one’s speech abilities with the proper post-operational therapies. Especially since Jerrod is still young, his brain has more plasticity than an older person’s brain, so he will find ways to adapt to his new lifestyle.

Sources:

Grubin, D. 2001. The Secret Life of the Brain. [Television series]. New York and Washington, DC: Public Broadcasting Service.

http://www.nlm.nih.gov/medlineplus/epilepsy.html

http://www.epilepsy.com/

http://www.ninds.nih.gov/disorders/rasmussen/rasmussen.htm

http://www.hopkinsmedicine.org/press/2002/November/021108.htm, http://www.hopkinsmedicine.org/press/2003/October/031014.htm

http://www.aans.org/en/Media/General%20Press%20Releases/2000/September/Hemispherectomy%20shown%20on%20ABC%20show%20%20Dr%20Ben%20Carson%20says%20most%20young%20people%20who%20have%20half%20their%20brains%20surgically%20removed%20do%20great.aspx?sc_database=web

http://brain.oxfordjournals.org/content/126/3/556.long#sec-12

http://my.clevelandclinic.org/neurological_institute/epilepsy/treatments-services/hemispherectomy.aspx

Wikipedia.org: “Thalamus,” “Amygdala,” “Basal ganglia,” “Brain stem,” “Hippocampus,” “Parietal lobe,” “Temporal lobe,” “Frontal lobe,” “Occipital lobe.”

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