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Penn State Neurology

Penn State Neurosugery

Epilepsy

What is it?

Epilepsy is a disorder that is characterized by the tendency to have seizures over and over again over a period of time, called recurring seizures. A seizure is a sudden disruption of the brain's normal electrical activity, which can cause a loss of consciousness and make the body twitch and jerk, called convulsions.

Who gets it?

About 25% of all cases of epilepsy develop before the age of five. One in every two cases develops before the age of 25. Some types of seizure disorders are inherited at birth, or tend to run in families.

What causes it?

There are clusters of nerve cells in the brain called neurons. A person's thoughts, feelings, and actions are produced by the electrochemical impulses that the neurons generate. Usually, the neurons send signals, or fire, around 80 times a second. Various conditions and stimuli can cause the neurons to fire abnormally, which causes a seizure. During a seizure, neurons may fire as many as 500 times a second. In about 50 to 70% of all cases of epilepsy, the cause of the abnormal electrical impulses is unknown. Epilepsy without a known cause is called ideopathic. 

Other forms of epilepsy occur because of brain injury at birth, which can be caused by insufficient oxygen to the brain, head injury, heavy bleeding; incompatible blood types between the mother and the child, and infection immediately before, after, or at the time of birth. One type of seizure disorder, called juvenile myoclonic epilepsy, is inherited at birth. Other causes include head trauma; alcohol abuse; birth defects; brain or spinal cord inflammation; diseases such as measles, mumps, and diphtheria; inhaling or ingesting poisonous substances such as lead, mercury, or carbon monoxide; or stopping anti-seizure medication suddenly. People with disorders including cerebral palsy, neurofibromatosis, pyruvate deficiency, tuberous sclerosis, Landau-Kleffner syndrome, and autism often suffer from epilepsy as a symptom. Epileptic seizures can be triggered by flashing lights, video games, repetitive sounds, lack of sleep, excessive alcohol consumption, stress, cigarette smoking, or hormonal changes during the menstrual cycle.

What are the symptoms?

Symptoms of epileptic seizures depend upon the area of the brain affected by the abnormal electrical discharge. The cerebrum, the part of the brain divided into the right and left hemispheres, is further divided into the frontal, parietal, occipital, and temporal lobes. The frontal lobes control motor behavior such as speech, mood, thought, and planning. Frontal lobe epilepsy usually involves a group of short seizures that begin and end suddenly. The parietal lobes interpret sensory input from the rest of the body and control body movement. Parietal lobe seizures tend to spread to other areas of the brain. The occipital lobes interpret vision. Occipital lobe epilepsy usually begins with visual hallucinations, rapid eye blinking, or other eye-related symptoms. The temporal lobes generate memory and emotions. Temporal lobe epilepsy (TLE) often begins in childhood and the seizures are signaled by an aura. The areas of the brain affected determine whether the symptoms are motor, in which parts of the body jerk and twitch; sensory, which causes numbness or tingling up and down one side of the body; visual, where the patient thinks he or she sees things that actually are not there; or auditory, which causes the patient to imagine voices, music, and other sounds. Seizures can also cause confusion, nausea, and emotional distress. 

There are many different types of epileptic seizures, each with different symptoms. People who have epilepsy may have more than one type of seizure. With a simple partial seizure, the abnormal electrical discharges occur in just a small area of the brain, called the focal area. Symptoms depend upon what part of the brain is affected. For example, if the electrical discharge occurs in the part of the brain that controls left arm muscle movement, the left arm may shake and jerk. The patient does not usually lose consciousness, and can describe the seizure when it is over.

 A jacksonian seizure is a partial seizure in which symptoms begin in one part of the body, such as an arm or leg, and then move up the affected limb as the electrical discharge spreads in the brain. Simple partial seizures can lead to complex partial seizures when the abnormal electrical discharge moves beyond the focal area. These seizures are often signaled by an unusual smell, taste, or sensation called an aura. For approximately one to two minutes, the patient may be completely confused, then stagger around, make unintelligible sounds, and resist any help. Temporal lobe epilepsy is the most common type of epilepsy syndrome with partial seizures. Complex partial seizures are also called psychomotor seizures because they affect consciousness and movement. Partial seizures can spread to other parts of the brain and cause a generalized seizure. Generalized epileptic seizures occur when electrical abnormalities exist throughout the brain. A generalized tonic-clonic (grand-mal) seizure usually begins with an abnormal electrical discharge in a small area of the brain, which then quickly spreads to adjoining parts of the brain until the whole area is affected. The person usually lets out a loud cry before losing consciousness and falling to the ground. While unconscious, the person's body becomes rigid, called the tonic phase, then the muscles alternately relax and contract, called the clonic phase. The tonic phase usually lasts for around 30 seconds, which the clonic phase lasts for 30 to 60 seconds. During the seizure, the patient will turn his or her head violently to one side, clench the teeth, and may lose bowel or bladder control. If the patient has trouble breathing, the skin may take on a bluish tint. A person who has a tonic-clonic seizure will be confused when he or she regains consciousness, and may have a headache, muscle aches, weakness in the arms or legs, and feel deeply tired. Absence (petit mal) seizures usually begin occurring around the age of four, and last from 15 to 20 seconds. A child having an absence seizure will usually lose consciousness briefly. He or she will become very quiet and may blink, stare blankly, roll the eyes, or move the lips. The seizure ends as suddenly as it began, and the child resumes his or her activity, completely unaware of what had happened. These types of seizures usually stop by adolescence. However, if left untreated, petit mal seizures can occur up to 100 times a day. They can eventually lead to tonic-clonic (grand mal) seizures. 

Status epilepticus is a life-threatening seizure disorder in which the seizure does not stop. The patient loses consciousness, has trouble breathing, and has severe muscle contractions and convulsions. Other types of epileptic seizures include juvenile myoclonic epilepsy, an inherited condition. Myoclonic seizures are characterized by brief, involuntary spasms of the tongue, facial muscles, arms, or legs. They are most likely to occur upon waking from a night's sleep. Akinetic seizures, also called drop attacks because they cause the patient to fall, also occur in young children. They are characterized by limp posture and a brief period of unconsciousness. Other types of epilepsy that begin in childhood include Lennox-Gastaut syndrome, characterized by several different types of seizures, including drop attacks, and Rasmussen's encephalitis, a progressive type of epilepsy in which half of the brain shows continual inflammation. coordination and cognitive abilities in addition to seizures. The most common type of infantile epilepsy is infantile spasms, which are clusters of seizures that usually begin before the child is 6 months old. Some epilepsy syndromes don't affect thinking or development. This is called benign epilepsy syndrome, and includes benign infantile encephalopathy and benign neonatal convulsions. 

Epilepsy syndromes that cause a person's cognitive or motor abilities to get worse over time are called progressive epilepsy syndromes. In many cases, epilepsy can cause the patient to develop behavioral and emotional problems. This is especially common in children.

How is it diagnosed?

Seizure disorders such as epilepsy are diagnosed through a description of symptoms during the seizure, and a test called an electroencephalogram (EEG). Electrodes are placed on the scalp to measure the brain's electrical activity and check for any abnormalities in the brain waves. The patient may need to be hospitalized for longer term EEG monitoring, or a video EEG, which records what the patient was doing during the seizure. If epilepsy is suspected, the doctor may order more tests to look for a possible cause. These may include blood tests to check sugar, calcium, and sodium levels, liver and kidney function, and white blood cell count; an electrocardiogram to check for an abnormal heart rhythm; and magnetic resonance imaging (MRI) or computed tomography (CT) scans to check for cancer, brain tumors, or signs of stroke or damage to the brain tissue. A spinal tap may be performed to check for brain infection. The doctor will also test the patient's motor skills, behavior, and intellectual skills to determine how the epilepsy has affected the person, as well as to determine what type of epilepsy the person has. Other techniques that are used to diagnose epilepsy are positron emission tomography (PET) and single photon emission tomography (SPECT), which monitor blood flow and chemical activity in the brain area being tested. Doctors may also use an diagnostic technique called a magnetoencephalogram (MEG). This test can pick up the magnetic signals generated by neurons so doctors can monitor brain activity at different points in the brain over time. A MEG can detect signals from deeper in the brain than an EEG. All these tests will help the doctor decide on a course of treatment.

What is the treatment?

A person having a seizure is never restrained. Healthcare providers recommend loosening the person's clothing and removing any hard or sharp objects on which he or she could get hurt. Never put anything in the mouth of someone having a seizure. However, if the seizure causes the person to bite his or her tongue, you can place a soft, folded cloth between the person's teeth and tongue. Turning his or her head to one side will help with breathing. Seizures caused by some underlying medical condition usually stop once the medical condition is treated. Epilepsy is treated with antiseizure drugs. Some people have to take more than one drug to control epilepsy. The most commonly used drugs are those containing phenytoin, carbamazepine, phenobarbital, primidone, valproic acid and sodium valproate, clonazepam, and ethosuximide. Patients on antiseizure medications must see their doctor regularly for blood tests to check the levels of the drugs in the bloodstream and to monitor any side effects. Side effects that should be reported to the doctor include sluggishness, dizziness, hyperactivity, uncontrolled eye movements, speech or vision problems, nausea or vomiting, or problems sleeping. Status epilepticus requires emergency treatment, usually with drugs such as Valium (Ativan), Dilantin, or Barbita. If the condition is caused by low blood sugar, the patient is given an intravenous (IV) sugar solution. 

Surgery is only considered for patients who have seizures that cannot be controlled with medication (called intractable epilepsy), or where the medication causes intolerable side effects. Brain surgery is most effective in cases where the doctor can pinpoint the affected area of the brain, and where the diseased brain tissue, called a lesion, can be removed without affecting normal brain function. There are several types of surgery used to treat intractable epilepsy. With a lesionectomy, the surgeon removes the lesion and some of the surrounding brain tissue. A temporal resection involves removing part of the temporal lobe, the area of the brain responsible for memory and emotions. While some patients experience post-operative speech and memory problems, this procedure is effective at controlling seizures in 75 to 80% of patients with epilepsy triggered in the temporal lobe area of the brain. An extra-temporal resection involves removing some or all of the frontal lobe, the part of the brain directly behind the forehead that controls speech, mood, thought, and planning. This procedure is most successful in patients whose seizures don't affect a widespread area of the brain. Patients with severe epilepsy and widespread abnormal electrical discharges may benefit from a hemispherectomy. Hemispherectomies are more commonly performed on infants or young children with extensive brain disease or disorders since birth or shortly after. Children who frequently injure themselves by falling during seizures may undergo a procedure called a corpus callosotomy. 

With this procedure, the surgeon removes some or all of the nerve fibers, called the corpus callosum, that separates the two halves of the brain. The surgeon usually begins by removing two-thirds of the corpus callosum. The remaining one-third is only removed if no improvement is seen. A multiple subpial transection is used to control the spread of seizures that originate in or affect the area of the brain responsible for complex thought and reasoning. Vagus nerve stimulation (VNS) is a non-surgical alternative that can be used in patients older than 16 who have intractable partial seizures. The vagus nerve runs from the side of the neck into the brain, and affects functions that include swallowing, heart rate, speech, and breathing. With VNS, a battery-powered device somewhat like a pacemaker is implanted under the skin of the upper left chest area. The device periodically stimulates the vagus nerve, which has been found to prevent or shorten some seizures. Alternative treatments that may help patients at least partially control their seizures include relaxation techniques, such as yoga or meditation, biofeedback, acupuncture or acupressure, and dietary changes. Epileptic children with behavioral and emotional problems often benefit from counseling.

Self-care tips

If you have epilepsy, you should wear a medical bracelet or necklace that identifies your disorder and lists any medications you take. You can help prevent seizures by following a healthy diet, getting plenty of sleep, and keeping your stress levels to a minimum. Since fevers can trigger seizures, take medication to lower fever at the first sign of illness. If your seizures begin with an aura, get to a safe place where you can lie down until the seizure passes. Also make sure those close to you know what to do when you have a seizure. You can protect yourself from injuries that cause epilepsy by wearing a helmet when riding a bicycle, skateboard, or motorcycle, or when playing sports, and wearing a seat belt when riding in a motor vehicle.

This information has been designed as a comprehensive and quick reference guide written by our health care reviewers.  The health information written by our authors is intended to be a supplement to the care provided by your physician.  It is not intended nor implied to be a substitute for professional medical advice.