What does focal activity in an EEG suggest?

Focal activity in an EEG indicates a specific area of the brain exhibiting abnormal electrical activity. This suggests that there is a localized dysfunction or disturbance in that particular region, which could be due to various conditions such as seizures, tumors, or lesions. Unlike diffuse brain activity, which would encompass a widespread or generalized disturbance across multiple brain regions, focal activity highlights that the issue is isolated to a particular area. Understanding focal activity is crucial for diagnosing conditions that may affect only a segment of the brain, thereby guiding treatment and intervention.