A seizure is a brief and abnormal electrical discharge from the brain that may cause different symptoms depending on where the discharge occurs and how it is distributed through the brain. The symptoms may range from brief confusion to minor spasms to major uncontrollable movements with loss of consciousness.
- Partial or focal seizures are the more common form and occur when a specific site on one side of the brain develops abnormal electrical discharge. Focal seizures may be simple where there is no change in consciousness or complex where there is partial or complete loss of consciousness.
- Generalized seizures have a more serious effect on an individual since more diffuse areas of the brain are involved. Generalized seizures are further classified into tonic-clonic seizures or absence seizures. A tonic-clonic seizure lasts about two to three minutes and involves major bodily movement and unconsciousness. Absence seizures or petit mal usually occur in children and are brief lasting about three to thirty seconds.
Who is likely to develop seizures?
About three percent of individuals will develop at least one seizure during their lifetime not counting infants and young children who develop seizures with fever. Infants who develop febrile seizures are unlikely to continue to have seizures as teenagers.
Seizures may occur after head injury and the risk is highest in severe injuries. The first seizure may occur days, weeks or even years after the head injury. If the head injury is mild with a brief loss of consciousness, then there is only a slight risk of seizure for up to five years after the injury.
Teens who are heavy abusers of alcohol may seize when withdrawing from the use of alcohol. The first seizure usually occurs seven to forty-eight hours after the last drink and is nearly always tonic-clonic.
Seizures may occur during meningitis or encephalitis. If there is brain damage, the seizure disorder may persist.
Brain growths may produce seizures. Both malignant and benign brain tumors can cause seizures for example neurofibromas in neurofibromatosis. Blood vessels that grow abnormally in the brain called cavernous hemangiomas may place pressure on brain tissue and cause abnormal electrical discharge.
Seizures may occur in patients who abuse drugs or who are being withdrawn from certain antidepressant or anti-anxiety drugs. Diabetics who have abnormally high or abnormally low blood sugars may also seize.
In some types of seizure disorders, the cause is unknown and genetics may play a role. The most common type of seizure developing during adolescence is juvenile myoclonic epilepsy. There is a strong genetic origin for this seizure disorder.
What are the symptoms of a seizure?
Simple focal seizures have no impairment of the teen’s level of consciousness. Motor movement is the most common symptom and this may consist of tonic or clonic movement of the face, neck or extremities. Patients with simple focal seizures are able to continue to talk, and there is no postictal phase after the seizure. Some patients experience hallucinations or feelings of déjà vu.
A complex focal seizure may begin as a simple focal seizure. Most of these seizures develop in the temporal lobe of the brain and as a result there may be changes in judgment, involuntary or uncontrolled behavior or some alteration to the level of consciousness. The symptoms may also include exaggeration of emotions, repetitive movements including chewing or smacking of lips or the initiation of a vacant stare. In most cases, the teen is not able to communicate during these seizures.
A grand mal or generalized tonic-clonic seizure begins in the tonic phase. The teen’s muscles involuntarily contract causing him or her to fall and become rigid for about ten to thirty seconds. Some teens develop an aura or sense that a seizure will occur just prior to the tonic phase. Some teens emit a shrill and piercing cry. The eyes roll back and then teen may turn blue. When the seizure enters the clonic phase, there are muscular spasms that occur for thirty seconds to minute. The teen may lose control of his or her urine or bowels. After the clonic phase, the teen may be unconscious for a few minutes, and then awaken to confusion and fatigue called the postictal state.
Absence seizures consist usually of a brief cessation of physical movement and loss of attention. These seizures are more common in childhood, but may persist into adolescence and adulthood. More prevalent in girls, there is no aura. The teen may have a sudden cessation of speech, motor activity with flickering of the eyelids. A teen could have numerous absence seizures each day.
How is a seizure evaluated?
A complete history and physical examination is important. A description of the seizure event from the patient and observers is particularly important. Immediate causes of seizures including head injury, blood sugar problems, brain infections, withdrawal from medications and illicit drugs should be considered. It is important that a seizure be differentiated from a fainting episode.
The most important diagnostic tool is the electroencephalogram or EEG. This test evaluates electrical brain waves and may be able to detect a seizure disorder from an abnormal appearance of the brain waves.
Often after the first seizure, a scan such as an MRI may be ordered. These are useful to detect damaged or scarred areas in the brain, tumors or abnormal blood vessels all of which could trigger a seizure.
There are other tests that may be ordered after the first seizure. Blood chemistries are usually determined to note if there are any chemical abnormalities that could trigger the seizure. If there is suspicion of drug use, drug testing may be done. And if there is fever with the seizure, a spinal tap may be performed to rule out meningitis or encephalitis.
How is a seizure treated?
There are numerous medications to treat seizures so that teens are able to have their seizure disorder controlled and have a normal lifestyle. Surgery to treat seizures is rarely utilized. Given the effects an uncontrolled seizure disorder could have on a teen’s self-esteem, academics, athletics and social life, compliance with clinician visits and medications is exceedingly important.
Emergency management may be necessary if there are two or more seizures occurring minutes to hours apart. Usually benzodiazepine medications may be used. Continuous seizures termed status epilepticus require emergency management consisting of intravenous medications, systems to maintain normal breathing, heart function, blood pressure and body temperature. Intravenous benzodiazepine is often used to stop the seizure activity.
Long-term drug treatment is usually considered for adolescents who have had two or more seizures or sometimes even after the first seizure. There is no single drug of choice and treatment usually begins with one drug. The drug is tailored to the specific type of seizure. The following are a few examples of drug regimens but there are others as well:
- Simple partial seizurescarbamazepine, phenytoin
- Complex partial seizurescarbamazepine, phenytoin
- Tonic-clonic seizures valproic acid, carbamazepine, phenytoin
- Absence seizuresvalproic acid
All medications used to treat seizure disorders have side effects, and some anti-seizure medications interfere with other medications. For example, several medications may interfere with the effectiveness of oral contraceptive pills. If the side effects are serious, then another drug may be substituted. Because of side effects, some teens refuse to take the medications.
- Carbamazepine side effects may include double vision, headache, sleepiness, dizziness and stomach upset
- Phenytoin may cause excess body hair, loss of appetite, swollen gums and anemia
- Valproic acid may cause liver problems, bruising, confusion and lethargy
- Phenobarbital may cause sedation and problems with cognition
There are other medications to treat seizures including primidone, ethosuximide and clonazepam. Newer medications that are not necessarily given as first line drugs include lamotrigine, gabapentin, topiramate and vigabatrin.
How is a seizure prevented?
The best preventive measure is to take medications as prescribed and follow up with the clinician as advised. Although most seizures do not have a known trigger, in a few adolescents, inadequate sleep can trigger a seizure. Others report that relaxation methods may be helpful as a preventive including Yoga exercises and meditation. It is important that diabetic teens control significant fluctuations in their blood sugar.
However, compliance with medication is the single most important preventive measure. Most adolescents with seizures are able to drive if they are seizure free for a certain length of time. It is exceedingly important to prevent seizures from recurring if a teen is allowed to drive.
Related topics:
academics, alcohol, automobile safety, compliance, depression, drug testing, fainting, gum disease, head injuries, meningitis, neurofibromatosis, self-esteem
