General Medical Officer (GMO) Manual: Clinical Section
Department of the Navy
Bureau of Medicine and Surgery
True seizures, also called epileptic seizures, are caused by the sudden,
uncontrolled discharge of a group of neurons in the cerebral cortex. These may affect the
entire cortex, causing a generalized seizure, or may begin focally or regionally, and
cause a partial seizure. An epileptic seizure can be triggered by a single event, or may
be due to a chronic tendency (diathesis) to cause seizures. Epilepsy is a condition with
recurring epileptic seizures. The following three cardinal characteristics set seizures
apart from other episodic behaviors or sudden losses of function, regardless of the cause
or type of seizure:
Generalized versus Partial (focal)
Seizures that begin focally are called partial seizures. A simple partial seizure does
not affect consciousness. Complex partial seizures originate in cortical areas that
control thoughts, images, or emotions without external signs of somatic involvement.
Some partial seizures may spread from the initial focal onset over several seconds, and
this may appear behaviorally to be a gradual onset, but the initial focal features are
sudden, and even the spread takes seconds, not a long time.
Complex partial seizures may begin with unusual thoughts, autonomic symptoms, or
repetitive behaviors. The same sequence is followed exactly with every attack. Dreamy or
fugue-like behaviors that respond to the environment, interactive conversations, or
directed violence are never seizures.
The patient will recall an aura or prodrome as the first manifestation of an actual
seizure, before the seizure progresses to a more intense stage. Since every partial
seizure tries to become a convulsion, it is critical to remember that an aura is a
seizure. If auras continue, the seizures are not completely controlled.
Generalized seizures involve the entire cortex. These may be secondarily generalized, by
spreading from a focal onset, or may be primarily generalized, involving the entire cortex
from the outset. One special type of generalized seizure, called absence seizure, causes
very brief staring spells. These spells last for only a few seconds. Since they are
generalized cerebral seizures, all consciousness is suspended during the seizure. Absence
seizures particularly affect children between the ages of 3 and 12, and they may occur
dozens to hundreds of times a day.
The most commonly encountered seizure in a military population is the generalized tonic
clonic seizure. A tonic seizure first has a generalized tonic phase lasting 1 to 5
seconds, followed by a series of accelerating generalized symmetrical clonic movements.
(Note: there is no such thing as a "tonic-clonic movement." There is a tonic
posture, and then there are clonic movements.) Observers may not detect a seizure until
the clonic phase is underway. However, the sequence is important if it can be recognized
Syncope may conclude with a few clonic jerks, but does not include a tonic phase.
Hysterical seizures may often have very convincing jerking movements, but usually omit the
tonic phase, which is less well known.
Treatment and General Principles
Treatment for seizures has become more complicated as a large number of seizure
medications have become available, and have relatively specific uses for particular kinds
of seizures. This section will not give detailed guidance on the diagnosis and treatment
of seizures because of the many varied considerations involved. However, general points
will be covered to clarify diagnostic and treatment issues. Referral to a neurologist must
be obtained for the complete diagnostic work-up and initiation of therapy. Here are some
general principles the GMO should keep in mind involving the diagnosis and treatment of
Seizures are a symptom. Find out the cause of the seizures.
Partial seizures suggest focal lesions.
An EEG clarifies the physiologic features of the seizure and may clarify focal
characteristics, but cannot show anatomic lesions.
A CT or MRI demonstrate anatomy and many types of lesions, but not physiology
Most seizures can be controlled with a single drug.
The most common reasons for seizures to occur despite treatment are either not using the
most effective drug for the specific seizure or using too low a dose.
The most effective drugs for absence seizures are valproate or
The most effective drugs for partial seizures and generalized tonic-clonic seizures are
carbamazepine, phenytoin, and valproate.
Phenobarbital and primidone are not first line drugs for any form of seizure.
Plasma drug levels are useful for monitoring compliance and fluctuations in the
patient's metabolism of the drug. Over time, induction or drug-drug interactions may alter
drug levels in circulation. However, drug levels are only adjuncts and guidelines in
managing therapy, they are not targets that can predict drug efficacy or side effects.
Most first seizures that occur in a military population will be generalized
tonic-clonic convulsions. The first step is to protect the patient from injury, and not to
make the situation worse. After placing the patient on the deck or floor, turn him or her
on the side, and place something soft under the head. The jaws will usually be clenched.
Do not place anything hard, like a tongue blade (even if padded) between the teeth. Ensure
the airway, breathing, and circulation (ABCs) are maintained as well as the safety
of the patient.
Next, try to make a diagnosis. Don't be too quick to treat. A single seizure may be
caused by alcohol withdrawal, some toxicants, or neurological disease (see causes). It is
important to examine the patient as soon as possible after the seizure, for signs of focal
deficit or evidence of associated disease. If the seizure is due to alcohol withdrawal, it
may be wise to treat the patient with a benzodiazepine drug. Do not initiate antiseizure
medications for alcohol withdrawal. If the seizure has stopped and the patient is within
an hour of a diagnostic center, do not initiate medication. Let the treatment be initiated
by the team who will be treating him or her.
Causes of Single or Transient
Chemical toxins: hydrocarbons, pesticides, fluorocarbons, etc.
Infection: encephalitis, meningitis, malaria
Parenchymal brain hemorrhage
Embolic cerebral infarction (not common)
Seizure vs Syncope
Syncope should be distinguished from seizures. Hypotension, hypovolemia, cardiac
arrhythmia, sudden increase in vagal tone, and sometimes extreme startling can cause
syncope. The commonest cause of syncope, in a military setting is prolonged standing,
especially in the heat. Syncope is usually preceded by a sense of lightheadedness or
weakness. The fall from syncope is a swooning collapse, whereas with a generalized
tonic-clonic convulsion, the patient is usually rigid and falls as though propelled. After
the syncopal episode and the victim falls, perfusion is usually rapidly restored and the
patient becomes alert fairly rapidly, although he may feel weak for minutes. After a
seizure, by contrast, there is a post-ictal period of stupor lasting many minutes to
nearly an hour. A patient usually has a headache after a seizure, rare after syncope.
Biting and injury to the tongue or lips is common with a seizure, rare in syncope. A
patient with a full bladder may urinate during either kind of spell, but it is a bit more
common with a seizure.
Continuous clinical or electrical seizures lasting more than 30 minutes without
an intervening lucid interval is called status epilepticus. This is a neurological
emergency. The seizures must be terminated as rapidly as possible to prevent permanent
brain damage as well as death from hypoxia, acidosis, rhabdomyolysis, and secondary renal
damage. This requires a team approach.
The first step is aggressive airway support to include intubation if necessary. Pulse
oximetry, cardiac monitor, and intravenous access are also necessary. Check a finger stick
blood glucose. IV infusion of a benzodiazepine
agent such a diazepam or lorazepam in doses
sufficient to arrest the convulsion are required, up to 20 mg of diazepam or 8 mg of
lorazepam over 5 to 10 minutes. This will almost always stop the convulsion. If it does
not, then an anesthesia provider should be requested to induce general anesthesia. The
patient will be severely acidotic at this time, for which good ventilation and
supplemental oxygen are the main treatments. While one member of the treating team takes
blood samples for electrolytes,
blood count, glucose,
calcium, a toxicology
blood levels of the patient's antiseizure medication (if applicable), another should push
100 mg of thiamine intravenously with an ampule of 50 percent glucose. This should be
followed by an ampule of naloxone.
A member of the team should vigorously seek out the patient's history to identify
antecedent events - especially a history of seizures. The most common cause of status
epilepticus in the U.S. and Europe is the discontinuation of medication in a person with
The effects of the initial dose of benzodiazepine
will usually wear off after 20
minutes, so a longer acting agent will be required, unless an underlying metabolic cause
for the seizure is identified. If the history does not disclose a treatable cause for the
seizures, or if the patient usually takes phenytoin, then infuse
phenytoin 15-18 mg/kg at
a rate of 50 mg/min. Avoid administering phenytoin along with glucose containing solutions
since phenytoin precipitates within the tubing. If seizures recur or continue, an
additional 7 mg/kg of phenytoin
should be given. If seizures still recur or continue, Phenobarbital
should be infused at a dose of 20 mg/kg. It is exceedingly rare for the
seizure to continue after all this, but if it does, general anesthesia is required.
If at this point, no cause has been identified, then an imaging study to identify
cerebral hemorrhage or mass should be done, rapidly followed by lumbar puncture to
identify meningitis or encephalitis.
Once stabilized, the patient should be transferred to a tertiary care facility for ICU
Revised by CAPT J. F. Morales, MC, USN, Neurology Specialty Leader, Department of
Neurology, National Naval Medical Center, Bethesda, MD (1999).
Approved for public release; Distribution is unlimited.
The listing of any non-Federal product in this CD is not an
endorsement of the product itself, but simply an acknowledgement of the source.
Operational Medicine 2001
Health Care in Military Settings
Bureau of Medicine and
Department of the Navy
2300 E Street NW
Health Care in Military Settings
CAPT Michael John Hughey, MC, USNR
January 1, 2001
|United States Special Operations Command
7701 Tampa Point Blvd.
MacDill AFB, Florida
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