Lennox-Gastaut syndrome
Lennox-Gastaut syndrome
Also known as:LGS, developmental and epileptic encephalopathy, China Second Rare Disease Catalog item 44
Lennox-Gastaut syndrome is a severe childhood-onset developmental and epileptic encephalopathy with multiple seizure types, drop attacks, cognitive and behavioral difficulties, and seizures that are often hard to fully control.
Start Here
A quick guide to the next step: which department to start with, what to prepare, and what to ask.
Repeated falls, tonic seizures during sleep, atypical absence-like episodes, myoclonic seizures, frequent seizures, or poor response to medicines should prompt pediatric neurology, an epilepsy center, or emergency care.
LGS usually combines multiple seizure types, characteristic EEG patterns, and developmental/cognitive-behavioral impact. Causes include brain injury or malformation, genetic or metabolic disease, prior infantile spasms, or unknown causes.
Treatment often requires combination therapy and may include ketogenic diet, vagus nerve stimulation, corpus callosotomy, or epilepsy surgery review. Goals often include fewer seizures, fewer injuries, and better function rather than guaranteed seizure freedom.
LGS is a syndrome diagnosis, not one single genetic disease. Genetic, metabolic, and imaging workup depends on age at onset, development, imaging, and family history.
Seizure types vary and may be mistaken for ordinary epilepsy, attention problems, accidental falls, or developmental delay. Video recordings are very helpful.
This page helps patients and families organize care leads. It does not replace a clinician’s diagnosis or treatment plan. For testing, medication, referrals, emergency care, and support applications, follow qualified clinicians, medical institutions, support organizations, and official sources.
Diagnosis Path
Organized around the practical patient journey: identify clues, avoid common delays, then prepare for care.
When to Suspect It
- A child has multiple seizure types, especially tonic seizures during sleep, atonic drop attacks, atypical absences, or seizure clusters.
- Seizures are frequent, poorly responsive to usual antiseizure medicines, or lead to repeated emergency visits.
- Language, cognition, behavior, or motor development plateaus or regresses.
- EEG suggests slow spike-wave or sleep-related fast rhythmic activity.
Common Wrong Turns
- Describing only falls or staring spells without showing seizure videos to an epilepsy specialist.
- Changing medicines repeatedly without systematic cause, EEG, imaging, and non-drug treatment review.
- Missing fall protection, helmets, sleep safety, school supports, and caregiver burden.
- No written rescue medicine and emergency plan for prolonged or clustered seizures.
Departments to Start With
- Pediatric neurology
- Epilepsy center
- Neurology
- Emergency medicine
Before the Visit
- Bring seizure videos and record timing, sleep/wake state, duration, triggers, and recovery.
- Bring EEG, long-term video EEG, brain MRI, genetic/metabolic testing, and medicine response records.
- Record developmental milestones, learning/behavior changes, fall injuries, and prior infantile spasms or brain injury.
- List all antiseizure medicines, doses, benefits, side effects, and reasons for stopping.
Tests to Ask About
- Long-term video EEG, especially including sleep.
- High-quality brain MRI to look for structural causes.
- Genetic testing, metabolic screening, or other cause-focused testing when indicated.
- Assessment for ketogenic diet, vagus nerve stimulation, corpus callosotomy, or epilepsy surgery options.
Questions for the Doctor
- Which seizure types does my child have, and which are most dangerous or highest priority?
- What is our rescue plan, and when should we use rescue medicine or call emergency services?
- Should we evaluate ketogenic diet, VNS, or corpus callosotomy?
- What school, sleep, activity, and fall-protection supports are needed?
Basic Information
Medical Notes
More complete medical explanations are kept here for discussion with clinicians.
Symptoms
LGS begins in childhood and causes multiple seizure types. Tonic seizures, atonic drop attacks, atypical absences, myoclonic seizures, generalized tonic-clonic seizures, and nonconvulsive status epilepticus can occur. Drop attacks can cause head, face, and limb injuries.
Many children also have cognitive, language, behavior, sleep, and motor-development difficulties. Seizures and medicine side effects can affect learning and family life.
Diagnosis
Diagnosis combines seizure history, developmental history, long-term video EEG, and brain MRI. Characteristic EEG findings include slow spike-wave and generalized fast rhythms during sleep, although patterns can change over time.
Clinicians look for causes such as brain malformations, hypoxic-ischemic or infection-related injury, tuberous sclerosis, genetic/metabolic disease, and prior infantile epileptic spasms syndrome, while distinguishing LGS from other developmental epileptic encephalopathies.
Treatment
LGS is often difficult to fully control, so treatment usually involves specialist-guided combination therapy. Medicines may include valproate, lamotrigine, topiramate, clobazam, rufinamide, felbamate, cannabidiol, or others depending on the child.
If medicines are not enough, ketogenic diet, vagus nerve stimulation, corpus callosotomy, or other epilepsy surgery strategies may be evaluated. Goals include fewer drop attacks and severe seizures, lower emergency risk, and better development and quality of life.
Long-term Care
Long-term care includes a seizure diary, rescue medicine plan, fall and head protection, sleep planning, rehabilitation, speech and special education support, and support for caregiver stress.
Fertility and Family
LGS has many causes and is not always inherited. If genetic or metabolic disease is suspected, identifying the cause guides family testing, recurrence-risk counseling, and reproductive planning.
When to Seek Urgent Care
A seizure lasting more than 5 minutes, repeated seizures without recovery, blue color or breathing trouble, serious fall injury, fever with sharply increased seizures, persistent sleepiness, or suspected status epilepticus requires the rescue plan and emergency care.
Prognosis
LGS often persists long term and seizure freedom is difficult, but systematic care can reduce severe seizures and injuries while supporting learning, rehabilitation, and family care.