Seizure Disorder

Definition

Seizures result when clusters of nerve cells in the brain, called neurons, communicate with each other abnormally. During a seizure, the neurons' normal pattern of activity is disturbed. This can cause strange sensations, emotions, and behavior; or convulsions, muscle spasms, and loss of consciousness. When a seizure occurs more than once without a known cause, the condition is called epilepsy.

Causes

Epilepsy is caused by abnormal brain wiring, which is often related to an imbalance of nerve signaling chemicals called neurotransmitters. This may occur during brain development or when the brain repairs itself after a head injury or stroke.
Other Seizure Disorders may be caused by:
  • Brain abnormalities existing since birth
  • Brain damage from other disorders:
    • Conditions that alter normal brain function: brain tumors, alcoholism Alzheimers disease
    • Conditions that deprive the brain of oxygen: stroke, heart failure, near drowning
    • Head injury leading to brain swelling or bleeding
    • Infectious diseases: meningitis, AIDS, viral encephalitis
    • Hydrocephalus (excess fluid in the brain)
    • Celiac disease (intolerance to wheat gluten)
  • Exposure to lead, carbon monoxide, or other environmental toxins
  • Exposure to certain illegal drugs
  • Overdose of antidepressants and other medications
  • In children:
    • High fever
    • Maternal infections
    • Poor nutrition
    • Oxygen deficiency

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Some factors, called seizure triggers, can cause first seizures or breakthrough seizures in people whose seizures are controlled with medication. These triggers include:
  • Lack of sleep
  • Alcohol consumption
  • Psychological stress
  • Hormonal changes of the menstrual cycle
  • Light flashing at a certain speed or the flicker of a computer monitor (photosensitive epilepsy)
  • Cigarette smoking
  • Certain medications

Symptoms

Symptoms include:
  • Convulsions
  • Brief stares
  • Muscle spasms
  • Odd sensations or emotions
  • Episodes of unusual or automatic behavior
  • Altered consciousness

Diagnosis

The doctor will perform a detailed examination to determine if you have epilepsy. The exam will include the following:
  • Questions about your medical history, including medications and current or previous health problems
  • Physical exam, especially of the nervous system
  • Blood tests
  • Lumbar puncture (possibly) – removal of a small amount of spinal fluid to determine if your seizure was caused by infection or bleeding in the brain (also called a spinal tap)
  • Electroencephalogram (EEG) – measures electrical activity of the brain to detect abnormal activity
  • Magnetoencephalogram (MEG) – monitors brain activity by measuring magnetic fields of the brain
  • Developmental, neurological, and behavioral tests
  • Brain imaging – detects brain tumors, blood clots, malformations, tissue scarring, swelling or hydrocephalus:
    • Computed tomography (CT) scan
    • Positron emission tomography (PET) scan
    • Magnetic resonance imaging (MRI)
    • Single photon emission computed tomography (SPECT)
    • Angiography – x-rays taken after injecting dye into the blood vessels leading into the brain
    • In babies, echoencephalogram – use of high-frequency sound waves to produce pictures of the brain

Treatment

Medications
Medications to prevent seizures are typically the first line of treatment. These medications are called anticonvulsants or antiepileptic drugs. They do not cure epilepsy, but for many people, they prevent seizures. Others may continue to have seizures, but less frequently.
Surgery
Surgery may be considered in the following situations:
  • When seizures occur in just one part of the brain (partial seizures)
  • When seizures begin as partial seizures before spreading to the rest of the brain
  • When medications dont control the seizures or they cause severe negative side effects
  • To treat the underlying cause of epilepsy, such as a brain tumor or excess fluid
  • When there is unilateral multifocal epilepsy with infantile hemiplegia such as Rasmussens encephalitis)
Surgeries to treat epilepsy include: Lobectomy or Lesionectomy – removal of the area of the brain that is producing the seizures, called the seizure focus
Multiple Subpial Transection – a series of cuts along the nerve path through which seizure impulses spread; designed to prevent seizures from spreading into other parts of the brain
Corpus Callosotomy –cutting the nerve connections between the right and left halves of the brain to prevent seizures from spreading from one side to the other
Hemispherectomy – removal of half of the brains outer layer
Vagus Nerve Stimulation
Prevents seizures by sending regular small pulses of electrical energy to the brain through the vagus nerve (a large nerve in the neck).
Ketogenic Diet
A diet very high in fat and low in protein and carbohydrate. It produces a change in body chemistry that controls or decreases the frequency of seizures in some children. It is sometimes used for children whose seizures cannot be controlled with medication, or who experience negative side effects from medication. It is unclear if this diet will work for adults. The long-term effects of such a high fat diet are unknown.

Prevention

To reduce your chance of getting a Seizure Disorder:
  • Prevent head injury by wearing seat belts and bicycle helmets, and putting children in car seats.
  • Take medication after first or second seizures.
  • Take medication to control high fevers in young children.
  • Get prenatal care, including treatment of high blood pressure and infections during pregnancy, to help prevent brain damage in a developing baby.
  • Prevent and treat heart disease, high blood pressure, infections, and other disorders that can affect the brain.
  • Avoid illicit drugs and excessive alcohol.