Which condition is characterized by chronic abnormal electrical activity in the brain that causes seizures?

Epilepsy is a neurological condition characterized by chronic abnormal electrical activity in the brain, which leads to recurrent seizures. This disorder affects how brain cells communicate with each other, causing sudden and unpredictable changes in behavior, movement, or consciousness. The distinctive feature of epilepsy is the presence of these unprovoked seizures, which can vary widely in their symptoms and severity.

When considering the other conditions: multiple sclerosis is primarily known for its effects on the central nervous system and can lead to various neurological symptoms, but it does not directly cause the type of recurrent seizures that define epilepsy. Stroke refers to a disruption of blood flow to the brain, resulting in brain cell damage, and while it can lead to seizures in some cases, it is not a condition characterized by chronic seizures. Parkinson's disease is a progressive neurological disorder that primarily affects movement and coordination but does not fundamentally involve the kind of electrical disruptions seen in epilepsy. Thus, epilepsy stands out for its specific link to chronic seizure activity as its defining characteristic.