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EPILEPSY

WHAT IS EPILEPSY?

Epilepsy is a neurological disorder. The brain contains millions of nerve cells called neurons that send electrical charges to each other. A seizure occurs when there is a sudden and brief excess surge of electrical activity in the brain between nerve cells. This results in an alteration in sensation, behavior, and consciousness.

Seizures may be caused by developmental problems before birth, trauma at birth, head injury, tumor, structural problems, vascular problems (i.e. stroke, abnormal blood vessels), metabolic conditions (i.e. low blood sugar, low calcium), infections (i.e. meningitis, encephalitis) and idiopathic causes. Children who have idiopathic seizures are most likely to respond to medications and outgrow seizures.

FACTS ABOUT EPILEPSY

• About 1.5 million people in America have epilepsy

• 25 percent of new cases of epilepsy occur in children 14 years and younger

• Epilepsy refers to more than 20 different types of seizure activity

• The cause is unknown in 70 percent of all cases of epilepsy

• Epilepsy is a physical condition. It is not a mental illness or a sign of low intelligence

• Children with seizure disorders can live a normal, active life, play sports and enjoy life

BASIC NEUROANATOMY OVERVIEW

GENERAL FUNCTIONS OF THE CEREBRAL CORTEX ACCORDING TO LOBES

Frontal lobes: Responsible for high level cognitive function, personality, memory, anxiety, alertness, and awareness; frontal and temporal lobes are the most epileptogenic

Temporal Lobe: Responsible for receptive and expressive speech, epileptogenic

Parietal Lobe: Responsible for bringing all perception together; called the association cortex, rarely the source of seizures

Occipital Lobe: Responsible for vision, uncommon origin of seizures

CLASSIFICATION OF EPILEPTIC SEIZURES

PRIMARY GENERALIZED SEIZURES

• Absence Seizures (Formerly called petit mal)
  Typical Brief episodes of staring, blinking, unaware of
  surroundings; usually lasts less than 10 seconds but may last up to 20 seconds
• Atypical
  Staring spells lasting between 5 to 30 seconds,
  eye blinking or slight jerking movement of the lips may occur; partial reduction in responsiveness
• Myoclonic
  Brief jerks of a muscle or group of muscles; usually
  involving the neck, shoulders, and upper arms
• Atonic
  Sudden loss of muscle strength, eyelids may droop, head
  may nod, objects may be dropped, or the child may fall to the ground; usually lasts less than 15 seconds, injury is common; child typically needs to wear a helmet
• Clonic
  Rhythmic jerking movements of the arms and legs, may
  be generalized
• Tonic
  Sudden stiffening movements of the body, arms, or legs
  involving both sides of the body; usually last less than
  20 seconds
• Tonic-Clonic (Formerly called grand mal)
  Convulsive seizures, body briefly stiffens followed by a
  jerking motion of the arms and legs; loss of consciousness and falls frequently occur, excessive saliva production may be present, possible loss of bowel and bladder control; usually lasts a couple of minutes, the child is often tired or confused after the seizure and may want to go to sleep

PARTIAL SEIZURES (SEIZURES ORIGINATING IN SPECIFIC PARTS OF THE BRAIN)

• Simple Partial (Focal seizures)
  Consciousness not impaired
  • With motor symptoms - Jerking and stiffening
  • With somatosensory symptoms - Touch, smell, hearing, taste, and sight
  • With autonomic symptoms - Heart rate change, internal sensations
  • With psychic symptoms - Dreamy state
    
• Complex Partial seizures
  Consciousness impaired
• Movements of the mouth and face (e.g., lip smacking, chewing, and swallowing movements), the hands and arms (e.g., fumbling, picking, and tapping movements), vocalizations (e.g., grunts or repetition of words or phrases)

DIAGNOSTIC TESTS

The accurate diagnosis of seizure disorders is crucial in tailoring an optimal treatment plan. The following is a list of diagnostic tests that may be utilized:

• Electroencephalogram (EEG) – This is a machine used to measure brain waves. It helps the neurologist identify the location, severity and type of seizure disorder. In many instances, however, a person with epilepsy can have an EEG done with no sign of seizure activity detected. This may occur when no activity was happening at the time of the test, or the seizure activity was so deep within the brain that the EEG machine was unable to detect it.

• Computed Tomography Scan (CT Scan) – This test helps identify blood clots, cysts, brain tumors, scar tissue or other problems that can cause seizures. The computer-generated view of the brain provides detail of the brain’s structure, section by section.

• Magnetic Resonance Imaging (MRI) – This test is used to identify structure and abnormalities within the brain. This technique utilizes a magnet rather than x-rays to generate a detailed picture of the brain. The procedure takes longer than a CT scan and it is painless.

• Outpatient/Inpatient Long Term EEG Monitoring – During this procedure a patient is video taped for a period of time while he/she is connected to electrodes to monitor brain activity. This test is utilized to confirm and diagnosis a seizure disorder. In some groups of patients with seizure-type movements, their condition is not related to epilepsy and that is why they are not responding to the different epilepsy-based treatment options. This test enables the physician to look at the patients movements and correlate this with the results on the EEG, thus allowing the doctor to confirm or reject a seizure diagnosis. Long term EEG monitoring is also a critical component of the surgical treatment of epilepsy to pinpoint the area of the brain responsible for the seizures.