Seizures and Hydrocephalus

Seizures

When people hear the word "seizure," the first thing that usually comes to mind is a person lying on the ground, writhing with convulsions. However, seizure activity can range from staring off into space for a few seconds to loss of consciousness with convulsions. Numerous medical conditions cause seizures, and treatments exist to control or eliminate them.

What causes a seizure?

Some of the causes of seizures in persons with hydrocephalus are:

• Reaction to a drug.
• Buildup of scar tissue in the brain from operations and shunt revisions.
• Infections such as meningitis or encephalitis.
• Brain abnormalities.
• Increased ICP.
• Subdural hematoma (SDH).
• Brain tumors or cysts.
• Metabolic conditions, such as hypoglycemia (a deficiency of sugar in the bloodstream), hyperglycemia (too much sugar in the bloodstream), electrolyte imbalances, uremia (excessive amounts of urea, waste products produced by the kidneys, in the bloodstream), and fluid overloads.

Children and adults with hydrocephalus are at increased risk of seizures, particularly if there has been a complication (such as an intracranial hemorrhage) during a shunt placement or revision procedure. Whatever the cause of the seizures, they should be taken seriously--seek immediate medical attention.

Phases of a seizure

Although the causes of seizures vary, seizures themselves tend to follow a general pattern.

There are essentially four phases to a seizure:

• The aura phase indicates the onset of a seizure. During the aura phase, the patient may fall into sudden unconsciousness, experience localized muscle spasms (including involuntary jerking or shaking of one hand, forced turning of the head, etc.), a sense of fear, false sense of smell, or a feeling of déjà vu. The patient may or may not experience all of these sensations. Most people have identical auras before each seizure, helping them predict when a seizure is imminent.
• The tonic phase is when all of the muscles in the body become tense or rigid. Patients often make noises--grunts or a shrill cry--prior to losing consciousness. The tonic phase usually lasts from a few seconds to a few minutes.
• The clonic phase, which may or may not follow the tonic phase, is associated with loss of consciousness, convulsions, loss of bowel and bladder control, salivation or drooling, and irregular breathing and heart activity. The clonic phase of a seizure can last from 1 or 2 minutes to 30 minutes or more.
• The postictal phase follows a seizure. The patient may or may not regain consciousness during the postictal phase. If he regains consciousness, he will most likely be tired, confused, and unaware of what happened or where he is.

Seizures do not always include the four phases mentioned here. For instance, your child may experience only the aura phase followed by the postictal. Or she may go from aura to tonic or clonic (one or the other), and then to postictal.

Types of seizures: partial and generalized

There are two main types of seizures: partial and generalized. Partial seizures are caused by specific areas of the brain. With partial seizures, the physical response directly corresponds to a region in the brain where the problem lies. The right side of the brain affects the left side of the body, and vice versa, so if muscle spasms are on the right side of the body, the problem will lie in the left side of the brain. It is rare that a person who is having partial seizures will lose consciousness, although he may feel dazed or confused following the episode.

Partial seizures are further categorized as:

• Simple-partial. The person does not lose consciousness during the seizure.
• Complex-partial. The person will lose consciousness.
• Secondary-generalized. The onset of the seizure can be directly attributed to one part of the brain, which then triggers a generalized seizure.

Generalized seizures are more severe and involve both sides of the brain. They are accompanied by convulsions, muscle activity on both sides of the body, and loss of consciousness.

First aid for seizures

Most people don't know what to do to help when someone near them has a seizure. The myth that someone having a seizure may "swallow his tongue" is physically impossible. Because of this myth, people tend to do more harm than good by trying to force something in the mouth of the person having a seizure to hold his tongue down.

The following are some dos and don'ts for helping a person who is having seizures. (You might want to photocopy this list for people who are likely to be nearby when a seizure occurs, such as neighbors or baby-sitters.)

What you should do

• If you do not know the medical history of the person having the seizure, check for an emergency medical identification bracelet or necklace.
• If you know the person and know they haven't had seizures before, send someone to call for emergency medical assistance (911).
• Make note of the time the seizure begins and how long it lasts. This information should be given to emergency medical professionals or the person's doctor.
• Try to protect the person from falling down if he loses consciousness. When he first starts to notice the aura, have the person lie or sit down on the floor in an area that is safe.
• Move any hard or sharp objects away from the person having the seizure.
• Surround the person with pillows, blankets, or cushions, if available. If possible, try to place some type of padding beneath the person's head to protect him from injury.
• Try to loosen any tight clothing the person may be wearing, including belts, ties, and shirt collars.

What you shouldn't do

• Do not attempt to place anything between the person's teeth or in his mouth during the seizure--especially your fingers or anything metallic. The person having the seizure might clench his teeth or bite down unexpectedly, causing harm not only to himself, but to you as well.
• Don't hold the person down or try to restrain him during the seizure. This could place both you and the person having the seizure at risk of injury.
• Do not attempt to move the person, unless he is near something immovable that could cause harm or injury to him.
• Do not yell at or get angry with the person having the seizure. Understand that he has no control over what his body is doing; getting upset with him will only make him feel worse afterward.

When to call for help

Since most seizures last for only one to two minutes, it isn't necessary to call for emergency medical services (EMS) personnel immediately. However, if the seizure lasts more than a few minutes, or if the person has one seizure after another, you should send someone to call EMS (911 in most states and provinces) immediately.

You should also call EMS:

• If the person has been injured.
• If the person is pregnant or suspected to be pregnant.
• If the person has diabetes.
• If the person is an infant or child.
• If the person fails to resume consciousness following the seizure.