epilepsy is characterized by focal or local clonic type convulsions of localized muscle
groups (for example, thumb, big toe, and so forth). The seizures normally last from
1-2 minutes.
d. Psychomotor. Psychomotor epilepsy is rare. Psychomotor epilepsy is
characterized by periods of abnormal types of behavior (for example, extensive chewing
or swallowing). The localized seizures may advance to generalized convulsions with
resultant loss of consciousness.
8-3. CAUSES OF EPILEPSY
a. In Children. Epilepsy that occurs in infancy usually results from
developmental defects, metabolic diseases, or injuries sustained during birth.
b. In Adults. Epilepsy that begins in adulthood usually is caused by trauma (an
accident), cerebrovascular accident (a "stroke"), tumors, or diseases associated with
the brain.
Section II. ANTICONVULSANT THERAPY
8-4. MECHANISM OF ACTION OF ANTICONVULSANTS
The mode and the site of action anticonvulsants are not known for sure.
However, it is believed that the anticonvulsants suppress seizures by depressing the
cerebral (motor) cortex of the brain, thereby raising the threshold of the central nervous
system (CNS) to convulsive stimuli. Therefore, the person is less likely to undergo
seizures.
8-5. SPECIFIC ANTICONVULSANT DRUGS
a.
Phenobarbital.
(1) Clinical uses. Phenobarbital is orally administered in the treatment of
grand mal epilepsy. It is less effective in the treatment of petit mal and psychomotor
epilepsy. The injectable from of the drug is used to treat other types of convulsions.
(2) Adverse effects. The most common adverse effects associated with
phenobarbital are related to sedation and disinhibition (see lesson 7 of this subcourse).
These include dizziness, drowsiness, ataxia (lack of muscular coordination), and
nystagmus (a rapid involuntary movement of the eyeball). Furthermore, as discussed in
lesson 7 of this subcourse, persons taking phenobarital can experience withdrawal
symptoms when they suddenly stop taking the drug. Epileptic patients are unusually
susceptible to the hyperexcitable state induced by too rapid reduction of dosage or too
rapid withdrawal of phenobarbital.
MD0804
8-4