Overview
Epilepsy is a neurological disorder characterized by a persistent predisposition to generate epileptic seizures.
Seizures result from abnormal, excessive, and synchronized neuronal activity and may produce a wide range of motor, sensory, behavioural, autonomic, or consciousness changes.
A single seizure does not automatically mean that a patient has epilepsy.
Seizure Classification
Seizures may be classified according to their onset as focal, generalized, or of unknown onset.
Focal seizures may occur with preserved awareness or impaired awareness and may progress to bilateral tonic-clonic activity.
Generalized seizures involve both cerebral hemispheres from the onset and include patterns such as absence, myoclonic, tonic, clonic, and tonic-clonic seizures.
Correct seizure classification is important because it guides both investigation and antiseizure medication selection.
Clinical Features
Clinical features vary according to the type of seizure. A patient may experience abnormal movements, altered awareness, sensory symptoms, automatisms, unusual sensations, or abrupt loss of consciousness.
Postictal confusion, fatigue, headache, or focal neurological findings may provide additional clues.
A careful witness history is often one of the most valuable diagnostic tools in suspected epilepsy.
Investigation
Evaluation aims to confirm whether the event was epileptic, classify the seizure, identify an underlying cause, and estimate future seizure risk.
Investigation may include electroencephalography, brain imaging, metabolic testing, and additional investigations according to the clinical context.
EEG can support the diagnosis and classification of epilepsy, but a normal EEG does not exclude epilepsy.
Management
Management depends on seizure type, underlying cause, recurrence risk, patient characteristics, and treatment goals.
Antiseizure medications are selected according to seizure classification and patient-specific factors.
Patients with drug-resistant epilepsy may require specialist evaluation for additional treatment strategies.
Treatment should target the patient's specific seizure type rather than treating all seizures as interchangeable.
Clinical Pearls
When evaluating a possible seizure, ask: What happened before the event? What happened during it? What happened afterward?
The distinction between focal and generalized seizures is clinically important because treatment choices depend strongly on seizure classification.
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