Epilepsy

Discuss the mechanisms underlying generalised and partial seizures and suggest drugs that might be used to control these seizure states, describing how these drugs work.

The characteristic event of epilepsy is the seizure. This is associated with the episodic high-frequency discharge of impulses by a group of neurons in the brain.

All types of epileptic attack start with an abnormal paroxysmal discharge of neurones from the brain. The discharge may spread locally to neighbouring groups of neurones or may travel via the axons to more distant group of neurones where the effect may be excitatory or inhibitory. The site of origin of discharge is called the focus. Generalised seizures involve the whole brain, including the reticular system, thus producing abnormal activity through both hemispheres. Immediate loss of consciousness is characteristic of generalised seizures. Generalised seizures can be classified into tonic-clonic seizures (grand mal), absence seizures (petit mal)...