Epilepsy

Definition

Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked seizures caused by abnormal electrical activity in the brain.

Epidemiology

• Affects about 50 million people worldwide.
• Incidence higher in children and elderly.
• Prevalence is higher in low- and middle-income countries due to increased risk factors such as CNS infections and perinatal injury.
• Males and females affected equally, though some seizure types show gender predilection.
• Genetic factors contribute to susceptibility, especially in generalized epilepsies.

Etiology

• Genetic mutations affecting ion channels or neurotransmitter pathways.
• Structural brain abnormalities: cortical malformations, tumors, stroke, trauma.
• Metabolic and infectious causes: hypoglycemia, CNS infections, neurocysticercosis.
• Idiopathic (primary) epilepsy without structural or metabolic cause.
• Risk factors: perinatal injury, head trauma, CNS infections, family history of epilepsy.

Pathophysiology

• Hyperexcitable neurons with abnormal synchronization lead to paroxysmal electrical discharges.
• Altered balance between excitatory (glutamate) and inhibitory (GABA) neurotransmission.
• Structural lesions can create epileptogenic foci.
• Seizure propagation through cortical and subcortical networks results in clinical manifestations.
• Status epilepticus occurs when seizure activity persists or recurs without recovery.