What are the key diagnostic criteria for confirming a diagnosis of epilepsy in adults?

Key diagnostic criteria for confirming a diagnosis of epilepsy in adults include:

• Having a history of at least two unprovoked seizures occurring more than 24 hours apart, or one unprovoked seizure with a high risk of recurrence based on clinical assessment.
• Detailed clinical history taking from the patient and eyewitnesses, including seizure description and any video evidence, is essential to support diagnosis.
• Physical examination and investigations such as a 12-lead ECG to exclude cardiac causes that may mimic seizures.
• Electroencephalography (EEG) is used to support the diagnosis and help classify seizure type or epilepsy syndrome, ideally performed within 72 hours of a suspected seizure; however, a normal EEG does not exclude epilepsy.
• Neuroimaging, preferably MRI, should be offered to identify structural causes unless the epilepsy is idiopathic generalized or self-limited epilepsy with centrotemporal spikes.
• Referral to a clinician with expertise in epilepsy diagnosis is recommended due to the complexity and risk of misdiagnosis.

These criteria align with NICE and SIGN guidelines emphasizing clinical assessment supported by EEG and MRI, with specialist referral for confirmation and classification of epilepsy type to guide management and prognosis ¹,².