Learn what happens when the brain's electric signals go awry and how you can help someone plagued by the disturbing effects.

HIPPOCRATES WROTE about epilepsy in 400 BC. Dispelling a prevailing myth that seizures were the work of evil spirits, he said that epilepsy was a brain disorder. Over the centuries, medical science has confirmed his theory, yet some mysteries still remain.

You may be uncertain about how to help someone who's having a seizure or who has a diagnosed seizure disorder. In this article, I'll clarify your role by exploring the various types of seizures, explaining their significance, and discussing how to care for patients affected by this bewildering problem.

What is a seizure?

Functioning as the body's control center, the brain transmits electrical impulses throughout the body. If an abnormal stimulus in the central nervous system (CNS) causes excessive and chaotic electrical discharge from neurons in the brain, temporary changes in cerebral function alter motor or autonomic function, consciousness, or sensation. The victim is having a seizure.

Seizure manifestations depend on the area of the brain involved. Specific phases have been identified:

* aura: a phenomenon some people experience that warns of full-blown seizure activity. It's characterized by certain changes, such as depression, irritability, or an unusual sensation such as smelling wood smoke. An aura can occur hours or even days before a seizure.

* ictus: the period of seizure activity

* postictus: the phase after the seizure during which the patient may be conscious but confused and tired. The postictal phase can last several minutes to hours. The victim may become lethargic and may not remember the seizure.

The pathophysiology of seizures remains unclear, but we do know that genetics plays a role in some cases. Seizures can be idiopathic or acquired:

* acquired. Possible causes include acidosis, electrolyte imbalances, hypoglycemia (particularly related to type 1 diabetes), hypoxia, alcohol and drug withdrawal, dehydration, systemic lupus erythematosus, hypertension, septicemia, tumors, and head trauma.

Several nonepileptic conditions can cause a series of paroxysmal events that mimic an epileptic seizure, but abnormal electrical discharges of CNS neurons aren't involved. Examples include syncope, hyperventilation, and pseudoseizures due to psychological conditions including panic and anxiety attacks. Differentiating between epileptic and nonepileptic seizure activity is essential to determine the appropriate treatment.

Seizures are classified as partial and generalized. (Tracing seizure activity shows the difference between them.)

Partial seizure-a one-sided event

Also known as a focal seizure, a partial seizure involves an abnormal electrical discharge in only one brain hemisphere. A partial seizure is simple or complex, depending on whether it affects the patient's consciousness.

During a simple partial seizure, the patient remains conscious and fully aware of what's happening, but she can't control it. She may experience jerking movement or localized pain in various body parts or a feeling of deja vu. Simple partial seizure activity can progress to a complex or a secondary generalized seizure.

A complex partial seizure indicates impaired consciousness without loss of consciousness. The patient appears fully awake but can't understand what's happening. She may display bizarre, involuntary automatisms such as rearranging objects, moving in circles, or repetitively smacking her lips or grunting. She won't respond to commands or remember the seizure when it ends. A complex partial seizure can originate anywhere in the brain but typically starts in the temporal or frontal lobe.

When a partial seizure spreads to the other side of the brain, it's known as a secondary generalized seizure.

Generalized seizure-widespread activity

A generalized seizure involves widespread abnormal electrical discharge across the entire brain cortex. The manifestations can range from violent motor activity, as in a convulsive seizure, to much less obvious signs.

A convulsive generalized seizure is what most people picture when they think of epilepsy. Also known as a tonic-clonic or grand mal seizure, a convulsive generalized seizure dramatically affects the patient and bystanders. (See Protecting your patient during a seizure for measures to keep her safe.) Causing loss of consciousness, a convulsive generalized seizure consists of three phases.

1. The tonic phase usually lasts 10 to 30 seconds. During this period, the voluntary muscles contract, so the arms flex and the legs extend. The patient may fall from a standing position, or if she's lying down, her body can tense into an awkward position. She may make screaming or crying sounds as her thoracic muscles contract, and she may lose bladder or bowel control. Even if her eyes are open, she's unresponsive and unaware of her environment.

2. The clonic phase follows, with rapid, rhythmic muscle contraction and relaxation that cause jerking in various body parts. The jerking may be limited to the patient's fingers or may involve her entire torso and extremities. She can't swallow, so saliva pools in her mouth and causes frothing. Secretions or relaxation of her tongue may obstruct her airway. The clonic phase seldom lasts longer than 2 minutes. The periods of relaxation typically lengthen until the seizure ends.

3. The postictal phase following a tonic-clonic seizure lasts 30 minutes to several hours, during which the patient lies very still as her brain recovers from the trauma. She may be confused, drowsy, nauseated, and disoriented.

A nonconvulsive generalized seizure has less obvious manifestations than a convulsive generalized seizure, so it's harder to recognize. Nonconvulsive generalized seizures are classified as absence, myoclonic, and atonic seizures.

An absence (formerly called petit mal) seizure is characterized by a brief interruption in consciousness without loss of postural control. This type of seizure typically affects children and doesn't occur after puberty. The child may have many periods of staring, eyelid fluttering, or lip smacking lasting up to 10 seconds each time, while her awareness and alertness are impaired. Unaware of what's happened, she immediately returns to normal activity when the seizure ends.

A teacher may be the first person to notice absence seizures and send home a note indicating that the child daydreams too much or appears to "blank out" frequently; both are signs of absence seizures. If absence seizures continue into adulthood, they usually progress into convulsive generalized seizures.

A myoclonic seizure is a nonconvulsive seizure triggered by environmental factors, such as flashing lights, that stimulate the CNS. Striking at any age, myoclonic seizures generally don't cause loss of consciousness. They commonly occur before sleep or after awakening and are characterized by sudden, sporadic jerking motions confined to one area or muscle group.

A nonconvulsive atonic seizure is also known as an akinetic or astatic seizure. Commonly referred to as a "drop attack," an atonic seizure is characterized by a sudden loss of postural tone, possibly causing the person to fall to the ground from a standing position. The seizure usually lasts only a few seconds; the person either doesn't lose consciousness or regains it before she hits the ground. Because sudden falls increase the risk of head and neck trauma, someone who has atonic seizures may be advised to wear head gear for protection. Atonic seizures typically begin in childhood and commonly recur into adulthood.

Protecting your patient during a seizure

Safety is a top priority. Remain calm and use these measures:

* Summon help and be prepared to use basic life support or advanced cardiovascular life support.

* If the patient is sitting or standing, lower her to a bed or to the floor. Raise the side rails on the bed. If necessary, use pads or cushions to protect her head from the side rails or hard floor.

* Place her on her side to prevent aspiration. Stay with her, but don't restrain her or hold her down. Both of you could be injured.

* Move objects such as I.V. poles to a safe distance to prevent injury.

* Provide privacy if possible.

* Don't put anything in her mouth. Forcing something into her mouth can break her teeth and cause you to be bitten.

* Observe her and let the seizure subside on its own, but be aware of the potential for status epilepticus. If seizure activity doesn't subside, contact the practitioner and follow prescribed orders. If the practitioner isn't available, call the rapid response team.

* Once the seizure is over, place the patient on her side in the rescue position if she's breathing and has a pulse. Be prepared to administer oxygen and medications as ordered.

* Once the patient is awake and alert, assess her and provide reassurance. Be sensitive and supportive to her and her family.

* Prepare her for diagnostic testing as ordered after the seizure.

* Document the events leading up to the seizure and the length and type of seizure activity, including the body parts involved.

* Investigate factors that may have precipitated the seizure, such as missed doses of antiepileptic drug, illness, menstruation, or stress.

The perils of status epilepticus

Status epilepticus is a potentially life-threatening complication of epilepsy identified by either of these criteria:

* two or more consecutive seizures without the patient regaining consciousness between them

A thorough medical history and physical exam are the first steps to determine why someone had a seizure. When you assess the patient, get detailed information from her and her family or bystanders about the seizure activity, including events leading up to it, the duration and type of seizure activity, and what they experienced or witnessed after the seizure ended. Other important information includes pertinent earlier life events (such as head trauma, stroke, and history of seizures), family history of seizures, and use of prescribed or recreational drugs.

A neurologist or other appropriate practitioner should perform a neurologic exam. Various diagnostic tests can help pinpoint whether the patient had a seizure and, if so, what caused it.

Blood work

Your patient's initial postseizure assessment should include serum glucose and electrolyte and plasma osmolality levels. Electrolyte imbalances and other abnormalities, such as hypoglycemia and a hyperosmolar state, can both trigger and result from seizures.

Assays of antiepileptic drugs (AEDs)

If your patient is taking a medication such as phenobarbital to manage seizures, checking her blood level will determine whether it's in the therapeutic range. Subtherapeutic and toxic levels fail to control epilepsy and they can cause such adverse reactions as gastrointestinal upset, headaches, drowsiness, and confusion.

The practitioner may order liver and renal function tests, thyroid studies, and arterial blood gases to monitor for imbalances that could alter the effects of AEDs. He may need to address liver, renal, or thyroid problems and explore other reasons for a subtherapeutic drug level, such as if the patient isn't adhering to prescribed therapy. The patient's medication regimen may have to be changed if blood studies show that current levels aren't in the therapeutic range.

Cardiac studies

Cardiac studies, such as an electrocardiogram, can help rule out other causes of seizure activity, including dysrhythmias.

Imaging studies

Various studies can detect structural abnormalities including arteriovenous malformations and brain tumors. In an emergency, a computed tomography scan of the head is preferred to detect intracranial problems because it can be done quickly, but magnetic resonance imaging of the brain is more sensitive and can detect more subtle lesions.

An electroencephalogram (EEG)

If the patient has a low risk of recurrent seizures (based on seizure type, EEG findings, and imaging results), the practitioner may recommend observation at home. This is a period of "watch and wait" to identify further seizure activity. The patient may have to take special precautions, including no driving. Certain states have mandatory reporting of seizure activity and suspend driving privileges for a certain period afterward.

Methods to manage seizures

Most seizure activity is self-limiting. Status epilepticus, however, warrants immediate intervention, such as drug therapy to terminate the seizure.

The goal of treatment for epilepsy is to prevent seizures and improve quality of life without adverse reactions to therapy. The patient will work with the neurologist to decide which approach is best for her. The available options include therapy with AEDs, surgery, and vagal nerve stimulation.

Medications don't cure the underlying cause of seizures, but maintaining blood levels of appropriate medication within the therapeutic range commonly controls seizures with few adverse reactions. Antiepileptic drugs decrease the number of seizure episodes in two ways:

* suppress activity of damaged neurons to minimize electrical discharge

* reduce responsiveness of neighboring normal neurons to block the spread of excessive electrical discharge to other parts of the brain.

Considerations in choosing an AED include its efficacy and adverse effects, long-term safety, tolerability, medication interactions, expense, and effect on the patient's quality of life. Typically, the patient starts AED therapy at a low dose and the dose is increased until seizure activity is adequately controlled. Starting at a low dose reduces the risk of adverse reactions and helps prevent toxicity. If her seizures persist, the dosage and timing may need to be adjusted or the neurologist may add another AED to her regimen.

Surgery may be an alternative for some patients whose seizures aren't controlled with medication. It may be most beneficial when seizures are triggered by structural brain abnormalities such as tumors, blood vessel malformations, and stroke-related injury. Postoperative seizure control isn't guaranteed, so the patient and the neurosurgeon must carefully weigh the benefits against the risks. Possible complications of brain surgery include infection, bleeding, and paralysis.

Two main surgical procedures are used to manage epilepsy:

* Resection, or resective surgery, is more commonly used. The neurosurgeon removes a portion of the temporal lobe and small portions of the hippocampus on the affected side.

* Disconnection surgery involves cutting through nerve pathways that let seizures spread. This surgery is appropriate when seizures begin in an area of the brain that's too critical to remove.

Your patient may undergo implantation of a vagal nerve stimulator under local anesthesia as an outpatient. The surgeon will make an incision in her left upper chest and implant a programmable pulse generator under the skin. Through a second incision in her neck, he'll wrap the stimulator wire around her vagus nerve.

Using a magnetic wand, the practitioner programs the pulse generator through the skin to send electric energy to the vagus nerve every few minutes. The patient also may learn to use a magnet to activate the vagal nerve stimulator if she has an aura. Every few years she'll need a minor surgical procedure to change the battery.

The downside of drug therapy

Teach your patient about the drugs used to manage seizures in adults and their possible adverse effects.

Drugs used as monotherapy

* phenytoin (Dilantin): dizziness, ataxia, slurred speech, nystagmus, confusion, gingival hyperplasia, nausea, vomiting

* valproate (Depakote): ataxia, tremors, sedation, headache, asthenia, weight gain, nausea, vomiting, anorexia

* carbamazepine (Tegretol, Carbatrol): dizziness, vertigo, ataxia, nausea, vomiting

* lamotrigine (Lamictal): drowsiness, diplopia, blurred vision, dizziness, headache, ataxia, rhinitis, nausea, vomiting

* phenobarbital (Luminal): drowsiness, sedation, confusion, rash

Adjunctive agents

* ethosuximide (Zarontin): ataxia, lethargy, headache, allergic reaction, nausea, vomiting, bone marrow suppression

* methsuximide (Celontin): ataxia, drowsiness, dizziness, nausea, vomiting

* clonazepam (Klonopin): drowsiness, ataxia, behavior disturbance, anorexia

* topiramate (Topamax): fatigue, paresthesia, cognitive effects, ataxia, nervousness, tremor, abnormal vision, nausea, anorexia

* tiagabine (Gabatril): dizziness, asthenia, somnolence, nervousness, nausea

* gabapentin (Neurontin): fatigue, sedation, dizziness, ataxia, nausea

* primidone (Mysoline): drowsiness, ataxia, diplopia, nausea, vomiting

* felbamate (Felbatol): insomnia, dizziness, sedation, headache, blurred vision, weight gain, decreased appetite, anemia, liver failure

* levetiracetam (Keppra): sedation, incoordination, leukopenia

* zonisamide (Zonegran): sedation, dizziness, confusion, headache, anorexia

* oxcarbazepine (Trileptal): tremors, ataxia, fatigue, dizziness, vertigo, diplopia, headache, nausea, vomiting, abdominal pain

* pregabalin (Lyrica): dizziness, somnolence, blurred vision, dry mouth, weight gain, peripheral edema

Drugs to treat status epilepticus

* lorazepam (Ativan): sedation, respiratory depression, hypertension

* phenytoin (Dilantin): see above

* fosphenytoin (Cerebyx): sedation, dizziness, ataxia, pruritus, tachycardia, hypotension

* phenobarbital (Luminal): see above

* midazolam (Versed): oversedation, respiratory depression, nausea

* propofol (Diprivan): hypotension, cardiac or respiratory arrest.

Seizures disrupt the lives of both the patient and those around her, so educate them about epilepsy and the prescribed treatment and offer emotional support. For example, reassure them that although a cure doesn't currently exist, many options are available to help her live a normal life. Cover the following points:

* Teach the family how to care for the patient during a seizure.

* Explain that the primary cause of breakthrough seizures is failure to take medication as prescribed. Stress the importance of adhering to the drug regimen, including taking the medication at the same time each day, exactly as prescribed. Also teach her and her family what to do if she misses a dose.

* Point out that she'll probably need periodic blood work to monitor for therapeutic drug levels. Emphasize the importance of having the levels checked as ordered to prevent toxicity or breakthrough seizures.

* Emphasize the importance of continued follow-up care with a practitioner and of consulting him if she's thinking of changing therapy for any reason, including alternative therapies.

* Teach the patient how to prevent injury due to a seizure. Warn her against working around hazardous materials and equipment, driving, working at heights, and swimming until she follows up with a neurologist or primary care provider and her condition is well controlled. Recommend patient and family support groups for additional help and make sure she understands her state's laws on driving for someone with seizure history.

Your understanding of seizures prepares you to protect a patient during a seizure and to teach her and her family how to manage an age-old problem.

REFERENCES

Gambrell M, Flynn N. Seizures 101. Nursing2004. 34(8):36-41, August 2004.

Smith P, Cossburn M. Seizures: Assessment and management in the emergency unit. Journal of Royal College of Physicians. 4(2):118-122, March 2004.