JOURNAL OF THE NATIONAL ACADEMY FOR CHILD DEVELOPMENT
1986, Volume 6, No. 6
Seizures
Robert J. Doman, M.D.
Normal brain activity produces a constant
flow of minute electrical waves which flow from every cell
of the cortex (gray matter) as well as the cerebellum and
the thalamus within the brain. These electrical waves vary
in their strength, which when measured on the EEG (electroencephalogram)
would represent the height or amplitude of the wave. The waves
also vary in their shape and frequency. These waves are measured
by an electroencephalogram, which is produced by a sensitive
electronic instrument which generally is attached to the patient
by eight wires or electrodes to measure waves in four different
areas of the cortex in each hemisphere (half) of the brain.
The most prominent form of brain wave
has a frequency between 6 and 13 waves per second and is called
an Alpha wave. Waves between 14 and 50 per second are called
Beta waves. Very slow waves between .5 and 5 per second are
called Delta waves. Generally sensory stimulation and Acidosis
(excessively acid blood) speed up the brain waves. Lack of
oxygen, sedative drugs, sleep, and relaxation slow down the
brain waves. Biofeedback and many forms of relaxation attempt
by conscious effort to help the brain produce more Alpha waves,
generally by sitting with the eyes closed.
A normal person has a brain wave pattern
which remains remarkably constant under similar conditions
from one year to the next. In a normal EEG there is a combination
of the various normal waves Alpha, Beta, and Delta. A newborn
child's brain waves are immature with small irregular waves
showing very little if any pattern. As the child's brain matures
so does the EEG showing a gradually more mature normal pattern.
A seizure is a temporary disruption
of the normal brain wave pattern. The same is true of a Convulsion,
an Attack, or an Epileptic Fit. They all represent some form
of disruption of the normal brain wave patterns. They all
may represent some form of body defense mechanism aimed at
attempting to prevent a temporary malfunction in the brain
from suffering further damage from such possible causes as
injury, pressure, lack of oxygen, lack of circulation, poisons
or toxins, edema (excessive fluid), or metabolic disturbances.
After seeing thousands of children and adults, many of whom
significantly regressed in brain function when seizures were
not properly controlled, NACD believes that control of seizures
is an important goal in treating such clients. To achieve
this goal, correction, in so far as possible, of any underlying
precipitating factors is critical. In all cases, testing for
and eliminating underlying causes by a competent Neurosurgeon
or Neurologist is essential.
Testing might include the following:
- Skull x-rays for possible craniostenosis (premature closure
of one or more of the skull sutures) or a possible undetected
fracture. Seizures are common in depressed (pushed down)
fractures.
- Urinalysis to help diagnose diabetes and other metabolic
disorders.
- A series of EEG's. Often a single EEG will appear normal
even when the patient has a seizure disorder. A series of
EEG's would pick it up and show whether it is getting better
or worse. Often I see a seizuring child who has not had
an EEG in over a year. In my opinion that is not good close
supervision of such a serious problem.
- Lab tests including a blood tests for sugar levels in
as much as a low sugar level may precipitate a seizure.
Other blood studies should be done to discover possible
metabolic disorders, the presence of any toxins or poisons
in the blood, etc. Periodic (usually every 3 to 6 months)
blood levels of any anticonvulsant medication is critical
to proper seizure control.
- CAT Scan (Computerized Axial Tomography). If a serious
brain disorder is suspected a brain scan should be done.
This important test presents images of the brain at many
levels. It is capable of showing most physical abnormalities
of the brain.
- Neural Magnetic Resonance Imager (MRI). This is a newer
way of viewing brain abnormalities in even greater detail
than the CAT scan.
Causes of Seizures
There are many causes of seizures.
Listed below are some of the common causes.
- Organic Brain Injury. This includes birth trauma, blood
incompatibilities, premature separation of the placenta,
oxygen deprivation from delayed or obstructed breathing
or the umbilical cord wrapped around the child's neck, tuberous
sclerosis, vascular accidents and malformations, trauma
such as fractures or edema (excessive fluid), pressure from
Hydrocephalus, or tumors, etc.
- Metabolic. Deficiencies of calcium, magnesium, Vitamin
B6, Hypoglycemia (low blood sugar), inborn errors of metabolism
such as PKU, Maple Sugar Urine Disease, Urenia, Liver disorders,
etc.
- Febrile (fever). This may not be serious the first time
but if persistent may lead to non-febrile seizures. Childhood
fevers require attention and treatment.
- Infections: Meningitis (bacterial or viral), Encephalitis,
Herpes Simplex, Cytomegatic Inclusion Diseases, etc.
- Poisons, Toxic Reactions, Toxins: Lead, arsenic, etc.;
drug overdosage, anti-convulsants, salicylates, etc.; Tetanus,
Pertussis, etc.
- Idiopathic: a fancy medical term for "We don't know!"
Conditions which may be mistaken for
seizures include the following:
- A startle reflex, which is a normal twitch, jerk, or jump
in response to a loud, sudden noise
- Breath holding
- Hyperventilation (breathing fast and deep)
- Shivering or urination
- Orthostatis Hypotension, which is weakness when standing
suddenly after a prolonged illness, etc.
- Daydreaming or "turning you off" could resemble
a Petit Mal
- Temper tantrums or hysteria.
If you are not sure if the patient
is or is not having seizures a series of EEG's is the best
way to find out.
Types of Seizures
There are many types of seizures and
many different names for seizures. Below are some of the more
common ones.
- Idiopathic where the cause is unknown.
- Petit Mal very brief (one or two seconds) lapses of attention
with staring or blinking eyes following which the child
resumes former activity. The EEG shows spikes and slow waves
(3 per second).
- Salaam sudden brief episodes of nodding (like the Indian
greeting).
- Myoclonic sudden jerking without loss of consciousness;
common in children and young adults.
- Akinetic sudden collapse without muscle jerking. The EEG
is like Petit Mal.
- Visceral or Autonomic Seizure Equivalent. The only outward
manifestation might be paleness, headache, or indigestion.
Diagnosis is best made by a series of EEG's. Every time
a brain injured child has one of these symptoms it does
not necessarily represent Visceral Seizures.
- Diurnal any daytime seizures.
- Nocturnal any nighttime seizures. Most seizures occur
at night or on awakening.
- Febrile a seizure, mild or severe, occurring with a fever;
usually in children between ages of 6 months and 3 years.
- Psychomotor a period of confusion followed by repetitive
meaningless movements. The EEG often shows temporal lobe
spikes. About 70% also have Grand Mal seizures.
- Grand Mal seizures sometimes start with an Aura, a cry,
or a weary feeling followed by loss of consciousness and
tonic movement often on one side of the body, with possible
loss of bladder or bowel control. This is followed by a
clonic jerking stage, which is followed by a long period
of sleep. The EEG shows sharp fast (25-30/second) spike
waves.
- Jacksonian or focal these are associated with localized
pressure as the result, for example, of a depressed fracture
of the skull or from a local or focal area of irritation
as from scar tissue or a cyst. They generally start with
jerking in one area of the body, which may spread over the
entire body. Neurosurgery may be necessary to reduce the
pressure of the depressed fracture.
- Hypsarhythmia massive myoclonic seizures with an onset
before one year of age with continuous high voltage slow
waves and spikes.
- Status Epilepticus a continuous state of uncontrolled
seizuring. Often the result of poorly treated seizuring
or sudden cessation of anticonvulsant medication. This generally
requires hospital care.
- Mixed types various combinations of the above types.
Generally each must have its own treatment.
Reprinted from the Journal
of the National
Academy for Child Development
Back to Top
|
