FoundationalConceptsNeuroscience

remain still largely uncharacterized. Certain configurations of neural
connectivity arising during the wiring of the brain early in life can
apparently increase the risk of occurrence of unbalanced runaway
neural excitation, and thus of seizure.
Susceptible persons may develop idiopathic seizures without any
precipitating factors. However, these seizures may be triggered in
a variety of identified ways. Intense sensory stimuli, especially of a
strongly rhythmic nature—such as brightly flashing strobe lights or
other flashing visual displays—can set up powerful rhythmic neural
activity in sensory regions of the brain that may lead to the explosive
runaway activity of a seizure. Other possible triggering factors in-
clude sleep deprivation, stress, physical trauma to the head, stimulant
drug use, and withdrawal from sedative-hypnotic drugs.
The prevalence of idiopathic seizures is actually quite high. Nearly
1 percent of the population in the United States is believed to suffer
from chronic, recurrent seizures, most of which are idiopathic. This
corresponds to about three million people in the United States—a
large number. The clinical condition of recurring seizures is called
epilepsy. Seizure disorders are generally diagnosed when people are
young. By the time someone is an adult, if they have a predisposition
to seizures, often they know it. This is why something like a seizure-
triggering television episode viewed by a very large number of young
children might reveal seizure disorders that have not yet emerged.
Seizures are about runaway overexcitation. Thus, a potential
treatment would be one that reduces the amount of excitation, or
enhances the amount of inhibition, in the brain. A number of avail-
able drugs do exactly that, and many are effective medications for
the treatment of seizure disorders. In the United States, at present
more than a dozen different pharmaceutical drugs are marketed as
antiseizure medications. As to the molecular mechanisms of how