The most useful way to diagnose the type of seizure is an electroencephalogram (EEG). This records electrical activity in the brain. The EEG can record unusual spikes or waves in electrical activity patterns. Different types of seizures can be identified with these patterns.
When a patient is experiencing nocturnal seizures, a sleep study is often needed to diagnose the condition. The sleep study will require the patient to stay overnight at the hospital where their brain activity can be monitored during their sleep.
Magnetic resonance imaging (MRI) and computed tomography (CT) scans may be used to look at where the seizures are happening in the brain. The scans can show scar tissue, tumors or structural problems in the brain.