Lennox-Gastaut Syndrome (LGS) is a severe form of childhood-onset epilepsy characterised by multiple seizure types. Nearly all people with LGS have some degree of intellectual disability, usually moderate to severe.
The cause of LGS is unknown in 1 out of 4 children. LGS is not something that anyone is born with, it develops over time and can evolve from other types of epilepsy such as infantile spasms, West Syndrome and tuberous sclerosis. It can also be caused by brain injury, infections, brain abnormalities, metabolic disorders, or genetic mutations.
Seizures
People with LGS experience different seizure types, and often have:
- tonic (muscle stiffening) seizures, also known as “drop attacks”,
- atonic (loss of muscle tone) seizures, also known as “drop attack”,
- tonic clonic seizures,
- atypical absence seizures,
- myoclonic seizures (sudden brief muscle jerks),
- focal seizures are sometimes seen.
Diagnosis
LGS may develop in children without a history of epilepsy but can also evolve from another type of epilepsy. The diagnosis may not always be obvious, and it may take several years to diagnose LGS in some circumstances.
Diagnosis is based on features which include:
- multiple seizure types, which are resistant to medical treatment.
- characteristic waveforms seen on EEG, which include slow spike-and-wave discharges and generalised paroxysmal fast activity (GPFA)
- presence of intellectual disability. People with LGS have varying degrees of intellectual disability and behavioral issues. Intellectual disability can range from mild to severe, and often worsens over time.
Management
LGS is notoriously difficult to treat and is drug resistant.
Seizures often do not respond well to medication, and multiple anti-seizure medication are usually taken. Other treatment options may include dietary therapies, vagus nerve stimulation (VNS), or even surgery in some cases to control the drop attacks.
Prognosis
LGS is a lifelong form of epilepsy. Outcomes can vary greatly depending on the person, seizures and underlying cause. Whilst medical or surgical therapies may help, they do not completely stop the seizures. This means there is an increased risk of seizure-related injuries, particularly head and facial injuries due to drop attacks, and an increased risk of early death known as Sudden Unexpected Death in Epilepsy (SUDEP).
LGS has a significant impact on quality of life of the person and caregivers due to frequent seizures, injuries, hospitalisations, cognitive impairment, behaviours and the challenges of drug-resistant epilepsy.
