Epilepsy in Adults with TSC
Individuals with tuberous sclerosis complex (TSC) face many medical issues as they age, including either new-onset seizures or ongoing epilepsy. Recent studies indicate that more than 80% of individuals with TSC will have epilepsy at some point in their life. The majority of individuals with TSC will face the onset of seizures before the age of 3. However, it is not uncommon for adults with TSC to develop new seizures or to experience a return of seizures after being well controlled for long periods of time.
Epilepsy and Seizures
Epilepsy is any brain disorder that causes repeated, spontaneous seizures of any type. Seizures (sometimes called “fits” or convulsions) are episodes of disturbed brain function that cause changes in attention or behavior. They are caused by abnormally excited electrical signals in the brain, like a lightning storm in the brain.
Seizure types vary from a momentary disruption of the senses, to short periods of unconsciousness or staring spells, to convulsions. Some people have just one type of seizure; others have more than one type.
Although they look different, all seizures result from a sudden change in how the cells of the brain send electrical signals to each other. The way seizures look depends on which part of the brain has the “lightning storm”. There are many underlying causes of seizures; TSC is just one cause of epilepsy.
What do seizures look like?
There are many different seizure types, some of which are only seen in young children. For example, infantile spasms often start at 6-12 months old and look like quick sudden tensing or flexing of the baby, usually in clusters over a few minutes. Infantile spasms may be associated with developmental delay. Children outgrow infantile spasms because they either go away or transition to other types of seizures. Tonic seizures consist of sudden whole body tensing that lasts for several seconds. A tonic seizure can lead into a clonic seizure of rhythmic whole body jerks that may last minutes. When there is a brief tonic phase followed by a clonic phase then it is termed a generalized tonic-clonic seizure, also called a grand mal seizure or convulsion, which is the type of seizure familiar to most people. Atonic seizures can cause injury because they consist of sudden loss of all body tone and falling to the ground, similar to fainting, but people are typically awake almost immediately. Lennox-Gastaut syndrome can follow infantile spasms or it can start later. It describes a condition with multiple seizure types, especially tonic, atonic, and generalized tonic-clonic seizures, along with developmental delay and a characteristic pattern of findings on EEG brain wave tests.
Other types of seizures may be diagnosed in individuals of any age, with some more commonly diagnosed in adults. Focal seizures begin in a small region of the brain and their appearance depends on where they begin. Since TSC can have tubers in almost any location, they can cause many different types of focal seizures with 1-3 minute episodes of altered thinking, consciousness, or behaviors. Complex partial seizure is a traditional term for seizures that cause “zoning out” or staring and inability to answer questions. Seizures that begin in the motor area of the brain may cause jerking of one body region for a few minutes.
The goal for adults with TSC who have epilepsy is to achieve the best seizure control possible while maintaining the best quality of life. If individuals with TSC experience an increase in frequency or severity of their seizures or the emergence of a new seizure type, they should discuss with their doctors various treatment options. These might include increasing the dose of an anti-epileptic medication that they have been taking, switching to a new medication or treatment, or adding another medication to their current treatment. Surgery to remove the spot where seizures arise is possible when seizures arise from just one spot in the brain but this is not common in TSC since the tubers are often distributed throughout the brain. Devices to treat epilepsy include vagus nerve stimulation and responsive neurostimulation.
Who Treats Epilepsy?
A general neurologist can treat uncomplicated epilepsy that is well controlled on one medication. However, most people with TSC will want to see a neurologist with special expertise because more than one seizure medication is required, seizures persist, or there are other neurological issues to monitor. A neurologist trained to treat individuals with epilepsy is called an epileptologist. Many epilepsy centers treat adults with epilepsy, so look for one of these centers in a large city and/or an academic center near you (for a listing of epilepsy centers go to www.naec-epilepsy.org or call 1-888-525-6232 or 952-525-4526). If you are transitioning from a pediatric neurologist to an adult neurologist then ask that physician whom they would recommend for your ongoing care as an adult.
Some TSC Clinics follow both children and adults, so ask about the upper age limit for individuals with TSC seen at the clinic. The TSC Alliance encourages the TSC Clinics to include physicians knowledgeable about TSC in adults so that there is a good transition of medical care for individuals with TSC when they turn 18. Find a in the USA or call the TSC Alliance at 1-800-225-6872 or 301-562-9890.
The majority of individuals with TSC will be diagnosed during childhood, most often following the onset of seizures. For some, the seizures will be well controlled with anti-epileptic medications that may be stable or may need to be changed and or modified over the years. In contrast, a large number of individuals with TSC will have intractable seizures—seizures that do not reduce in severity or frequency with the use of numerous anti-epileptic medications. For these individuals, seizures can be an ongoing, life-long battle. Often, new treatments can significantly help individuals with TSC who have seizures that are not completely controlled.
Some individuals with TSC who do not have seizures as children will begin having seizures as adults. Generally, the seizure type(s) experienced by adults with TSC will be more easily treated with anti-epileptic medications than childhood-onset seizures.
Occasionally, the onset of seizures will result from a buildup of pressure in the brain due to the presence of a subependymal giant cell astrocytoma (SEGA), a non-cancerous tumor that occurs in about 15% of individuals with TSC. Individuals with TSC often undergo magnetic resonance imaging (MRI) of the brain throughout adolescence and early adulthood (at least until the age of 21 years) to monitor for the presence and growth of a SEGA.
In adults with TSC who have been previously undiagnosed, the first sign of the tumor may be blurring of vision and/or the onset of seizures, but the symptoms may be more subtle. A brain MRI can reveal whether a SEGA may be blocking the flow of cerebrospinal fluid around the brain, causing increased pressure on the brain. In many individuals, the SEGA can be removed by surgery. Everolimus was approved by the Food and Drug Administration (FDA) in October 2010 for treatment of TSC-associated SEGAs that are not candidates for curative surgery.
Evaluation of New-Onset Seizures
All individuals with new-onset seizures should request a referral to a neurologist, preferably one who is an epileptologist with knowledge of TSC. This neurologist will perform a complete neurological exam, as well as brain imaging (MRI or CT) and an electroencephalogram (EEG) to determine if there is abnormal brain wave activity. They may perform other examinations to identify the cause of the seizures and the type of seizures. Sometimes it may be necessary to complete long-term EEG using an ambulatory outpatient EEG monitor (a portable device) that can be worn at home. Alternatively, the neurologist may require inpatient video EEG monitoring that requires a stay in the hospital where medical professionals are able to record both EEG and video to determine what the seizure looks like and how it is associated with brain wave changes. The test results will guide the physician and the individual to make the best choice of treatment for the seizure type(s) the individual with TSC is encountering.
Issues for Women with TSC
Hormonal fluctuations of the menstrual cycle can influence the incidence of some types of seizures. Not all seizures are sensitive to estrogen and progesterone ratios; however, this possibility may influence the choice of hormonal contraceptives. Importantly, women with TSC are at risk of developing the lung manifestation lymphangioleiomyomatosis (LAM). Use of estrogen is not advised for women with LAM, so it is critical for a woman with TSC who has epilepsy to discuss these medication issues with her health care providers.
Additionally, some anticonvulsant medications can interact with estrogen-based contraceptives and the result can be a lowered rate of efficacy, leading to unintended pregnancy. A higher dosage estrogen pill might be appropriate for women using epilepsy drugs that affect the rate at which the liver metabolizes estrogen. The dosage for emergency contraception (morning after pill) will also depend on the type of anticonvulsant medication a woman takes. The use of barrier methods such as a diaphragm, sponges, or condoms is appropriate for women with epilepsy.
Furthermore, women with epilepsy have special concerns when they decide to get pregnant. Some anti-epileptic drugs are not advised for women who are pregnant, so it is important to discuss this with both your neurologist and gynecologist/obstetrician as soon as you decide to—or find out you are—pregnant. Women with TSC are also encouraged to meet with a geneticist or genetic counselor so that they fully understand the risk of passing TSC on to their children. Each child of a woman with TSC has a 50% chance of inheriting TSC, so pregnancy is something that needs to be carefully considered and discussed between the prospective parents.
Issues for Men with TSC
Many men with epilepsy will experience changes in sexual drive and performance. For example, many men report a decrease in sex drive and almost one-third of men with epilepsy report difficulty achieving and maintaining an erection, known as erectile dysfunction (ED). In many cases, ED may result as a seizure medication side effect but other medical issues may cause ED. However, this reaction to one medication does not mean you will have the same experience with another. Recurrent uncontrolled seizures may also lead to diminished sex drive and ED. In fact, when seizures are under control, people seem to have improved sexual desire and performance. Men experiencing ED should visit a urologist to get help determining a cause and getting treatment. In addition, men should talk with their neurologist or epileptologist about trying another seizure medication, if possible, in case the ED is a side effect of one medication.
Hormones play an important role in sexual function, and some men with epilepsy have alterations in normal hormone levels. Both seizures and anti-epileptic medications can interfere with the way the body uses hormones, resulting in sexual problems. An endocrinologist, or endocrine specialist, may be able to help sort out the complex interactions between hormones, seizures, and medications.
Issues of Importance for Health Care Providers
An important point for adults with TSC to remember is that they need to be advocates for their own health care. In the case of severely learning-disabled adults, their parents/caregivers/guardians need to be the advocate to achieve the best seizure control possible while also optimizing the individual’s quality of life. Health care providers should remember that every individual with TSC deserves the best quality of life possible, so they should work with the caregivers to reach a balance between seizure control and side effects of the medication.
There are many treatment options for epilepsy, including anti-epileptic medications, the vagus nerve stimulator, responsive neurostimulation, surgery and dietary therapies.
- Anti-epileptic medications: There are numerous choices of anti-epileptic medications for the treatment of epilepsy in adults with TSC. Working with a knowledgeable neurologist, you should identify the medication that will best treat the specific seizure type you have while minimizing the side effects. Some anti-epileptic medications will treat other conditions, such as migraine headaches so this will be considered in the choice of medication.
- Vagus nerve stimulator (VNS): The VNS has provided improved seizure control for some individuals with TSC. Similar to anti-epileptic medications, about one-third of individuals with epilepsy and TSC who use the VNS will have a greater than 90% reduction in their seizure frequency, one-third will have more than a 50% reduction in seizures, and one-third will not respond to the VNS or will only see slight improvement. It is not possible to determine before implanting the device who will and will not respond. Adults with TSC should discuss this treatment option with a neurologist to see if it is a treatment that might benefit their individual situation.
- Epilepsy Surgery: Surgical approaches to treating epilepsy in individuals with TSC are becoming more and more refined and successful. When the seizure focus can be identified using brain imaging and EEG, then that portion of the brain can be surgically removed as long as it would not remove a portion of the brain critical to the individual’s quality of life, such as physical or language abilities. Although surgery is more commonly used in children with TSC, some adults with TSC have undergone surgery with great success. If an individual and his or her neurologist determine that this treatment should be considered, the individual should consult with an epilepsy surgery program.
- Dietary therapy: The ketogenic diet is a diet that is high in fat content and low in carbohydrates that has been effective in treating epilepsy in some individuals with epilepsy. This diet is more often used for children rather than adults due to its restrictiveness. The low glycemic index diet and modified Atkin’s diet are modifications of the ketogenic diet that are more palatable for some individuals.