Epilepsy

📖 Overview

Epilepsy is a neurological condition characterised by recurrent, unprovoked seizures caused by abnormal electrical activity in the brain. It is one of the most common neurological conditions worldwide.

Seizures vary enormously in type and presentation. Understanding the type of seizure matters — it affects diagnosis, treatment, safety planning, and how people around the person should respond.

TYPES OF SEIZURES

Tonic-Clonic Seizures (formerly Grand Mal)
The most recognised seizure type. Involves two phases: the tonic phase (muscles stiffen, the person falls, may cry out) and the clonic phase (rhythmic jerking of limbs). The person is unconscious during the seizure. Afterwards there is a postictal phase — confusion, exhaustion, headache, and sometimes temporary weakness (Todd's paresis) that can last hours. Most tonic-clonic seizures end within 1-3 minutes. One lasting more than 5 minutes is a medical emergency.

Absence Seizures (formerly Petit Mal)
Brief episodes — usually 5-30 seconds — where the person appears to stare blankly and switch off. There is no falling, no jerking, and often no awareness that anything happened. The person may flutter their eyelids or make small movements. Absence seizures can happen dozens or hundreds of times a day. They are frequently mistaken for daydreaming or inattention and may go undiagnosed for years.

Focal Seizures (formerly Partial Seizures)
Focal seizures begin in one specific area of the brain and may stay localised or spread to become generalised. They are divided into:
Focal aware seizures (formerly simple partial) — the person remains conscious and may experience unusual sensations, emotions, movements, or automatic behaviours. They may describe a strange smell, a rising feeling in the stomach, déjà vu, or involuntary movement of one limb.
Focal impaired awareness seizures (formerly complex partial) — consciousness is affected. The person may appear confused, make repetitive automatic movements (automatisms) like lip-smacking, chewing, or fidgeting, and have no memory of the episode afterwards.

Myoclonic Seizures
Sudden, brief muscle jerks — often in the arms, legs, or whole body. May occur in clusters, often shortly after waking. Common in juvenile myoclonic epilepsy. The person usually remains conscious.

Atonic Seizures (Drop Attacks)
Sudden loss of muscle tone causing the person to drop to the ground without warning. Significant injury risk. Helmets are sometimes used for people with frequent atonic seizures.

Infantile Spasms (West Syndrome)
A severe epilepsy syndrome beginning in infancy, involving clusters of brief body spasms. Associated with significant developmental impact. Requires urgent diagnosis and treatment.

Dravet Syndrome
A severe, treatment-resistant epilepsy beginning in the first year of life, caused in most cases by mutations in the SCN1A gene. Characterised by prolonged febrile seizures initially, then multiple seizure types. Significant developmental and cognitive impact. Some antiseizure medicines can worsen particular Dravet seizure patterns, so medication choice must be made by a clinician experienced in Dravet syndrome.

Lennox-Gastaut Syndrome
A severe epilepsy syndrome characterised by multiple seizure types, intellectual disability, and a characteristic EEG pattern. Treatment-resistant in most cases.

STATUS EPILEPTICUS
A generalised convulsive seizure lasting 5 minutes or more should be treated as convulsive status epilepticus and needs immediate emergency treatment. Repeated seizures without recovery, or a seizure lasting more than 2 minutes longer than the person’s usual convulsive seizure, may also meet the person’s emergency criteria. Follow the individual emergency plan, give prescribed rescue medicine if trained and authorised to do so, and call your local emergency number when indicated.

Sudep

Sudden Unexpected Death in Epilepsy (SUDEP) is an important but uncommon risk that should be discussed in an individualised way. Risk is higher with uncontrolled generalised tonic-clonic or focal-to-bilateral tonic-clonic seizures and poor medication adherence. For people with seizures during sleep who are at higher risk, clinicians may discuss night-time supervision or monitoring as part of a personalised risk-reduction plan. No device can guarantee prevention.

Epilepsy And Neurodivergence

Epilepsy is more common in several neurodevelopmental and genetic conditions, including autism, Angelman syndrome and Rett syndrome. When a person also has communication or intellectual disability, seizure recognition, medication side effects and emergency planning may need adapted communication and closer observation.