Epilepsy

Epilepsy

Its defined as a sudden, excessive, and synchronous discharge of cerebral neurons. This abnormal electrical activity may result in a variety of events, including loss of consciousness, abnormal movements, or distorted perceptions that are of limited duration but recur if untreated.
The neuronal discharge in epilepsy results from the firing of a small population of neurons in some specific area of the brain that is referred to as the primary focus. Focal areas that are functionally abnormal may be triggered into activity by changes in any of a variety of environmental factors, including alteration in blood gases, pH, electrolytes, blood glucose level, sleep deprivation, alcohol intake, and stress.
It is expected that seizures can be controlled completely in approximately 70 to 80 percent of patients with one medication. It is estimated that approximately 10 to 15 percent of patients will require more than one drug and perhaps 10 percent may not achieve complete seizure control.

Idiopathic and Symptomatic Seizures
A. Idiopathic epilepsy
Its called so when no specific anatomic cause for the seizure, such as trauma or neoplasm, is evident. These seizures may result from an inherited abnormality in the central nervous system (CNS).

B. Symptomatic epilepsy
A number of causes, such as tumors, head injury, hypoglycemia, meningeal infection, or rapid withdrawal of alcohol from an alcoholic, can precipitate seizures.

Classification of Seizures

A. Partial
Simple partial
Complex partial

B. Generalized
Tonic-clonic
Absence
Myocloni
c
Febrile seizures
Status epilepticus

Mechanism of action of antiepileptic drugs
Drugs that are effective in seizure reduction have a variety of mechanisms, including blockade of voltage-gated channels (Na+ or Ca2+), enhancement of inhibitory GABAergic impulses, or interference with excitatory glutamate transmission. Some antiepileptic drugs appear to have multiple targets within the CNS. The antiepilepsy drugs suppress seizures but do not cure or prevent epilepsy.

Antiepileptic Drugs