SIGNS AND SYMPTOMS
Age of Onset
LGS usually develops in the preschool years.
In about one in four cases, it evolves from another type of epilepsy. In these cases, it usually evolves from an epilepsy that starts very early in life. LGS most commonly evolves from infantile spasms or West syndrome.
It usually takes time for all features of LGS to appear. Therefore, it can be challenging to accurately diagnose the disease early in childhood.
Seizure Types Seen in LGS
Persons with LGS have several types of seizures. These can include:
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- Tonic seizure. This is the most common type in LGS. They consist of neck, and sometimes arm and leg, stiffening. They often involve eye opening and upward eye rolling. They often occur in sleep. They can be subtle and easily missed. An overnight-video laboratory test can reliably detect them. If they occur in the day, while a child is upright, they can result in a fall.
- Atypical absence seizure. This type consists of brief blank-outs where a child is less aware.
- Atonic seizure. In atonic seizure, a child abruptly loses body tone and slumps. If these occur while sitting, they can look like a quick head nod. If they occur while upright, they can lead to abrupt falls and injury.
- Myoclonic seizure. These consist of isolated, brief body jerks.
- Focal impaired awareness seizure. These typically begin with staring and altered awareness. This lasts up to several minutes and are followed by a period of confusion. These seizures can progress into generalized tonic-clonic seizures.
- Generalized tonic-clonic seizure. These consist of generalized stiffening and rhythmic shaking.
Other Symptoms of LGS
Intellectual Disability
Persons with LGS nearly always have intellectual disability. It may be mild in earlier childhood. However, those with LGS often gain developmental skills more slowly. They may have moderate to severe intellectual disability by adolescence. Behavioral differences are also common. They become more of a problem with age. Behavioral issues include:
- Aggression
- Autism spectrum disorder
- Inattention
- Hyperactivity
Motor and Mobility Difficulties
Most children with LGS also have motor difficulties. These include:
- Problems with balance and coordination. This is a common motor difficulty.
- Problems with feeding and swallowing. A small number require a feeding tube.
Limited mobility and frequent seizures can also mean a higher risk of infections such as pneumonia.
Risk of Death
Children with LGS are at higher risk of death. This is for several reasons:
- Sudden Unexpected Death in Epilepsy (SUDEP). This is a major concern in LGS. The exact cause of SUDEP is not well understood. However, it may be related to post-seizure heart and breathing issues. Those with frequent convulsive seizures are at the highest risk.
- Infection. Lower mobility can lead to infection. Pneumonia is an example.
- Accidental injury. Seizures, particularly atonic or tonic seizures, may cause falling and injury.
LAB INVESTIGATIONS
There are several useful ways to investigate LGS:
EEG and Diagnosing LGS
An electroencephalogram, or EEG, is a type of medical test. It measures the electrical activity of the brain. Those with LGS will have an abnormal EEG result. Several typical electrical patterns are seen in most children with LGS.
The top two are known as:
- Generalized paroxysmal fast activity
- Generalized slow-spike and wave discharge
Imaging
MRI, or magnetic resonance imaging, can find structural causes of LGS. This may guide treatment decisions. MRI can detect:
- Cortical malformations
- Tuberous sclerosis
- Tumors
- Acquired brain injury
There is no characteristic MRI pattern for LGS. The MRI may be normal.
MRI scans are not all the same. An epilepsy-protocol MRI read by an experienced epilepsy neuroradiologist increases the likelihood of detecting an abnormality if one is present.
Genetic Testing
Sometimes, an MRI does not provide a cause. In these cases, a genetic test is recommended. These include:
- Epilepsy gene panel. This is one of the most common genetic tests for epilepsy. It looks for many different genes associated with epilepsy.
- Chromosomal microarray. This evaluates extra or missing pieces of a chromosome.
- Whole exome sequencing. This can be ordered by a genetics specialist. It evaluates the entire DNA code. It looks for changes in genes associated with epilepsy. Usually, it requires a child and both parents to be tested.
Other Lab Testing
Repeat Testing
Repeating testing or imaging in older LGS patients can be useful. It can help when an underlying cause has not been determined. It can identify previously missed causes. However, it is not necessary in all cases. Sometimes, genetic testing can be reviewed rather than repeated as knowledge about genetics grows.
Testing Costs
Insurance generally covers most tests listed above.
Genetic testing coverage varies by state and insurance provider.
TREATMENT
There are several ways to treat LGS.
Antiseizure Medication
Medications can treat LGS. They can significantly reduce the seizure frequency. However, they do not lead to freedom from seizures.
Valproic acid is a first-line medication. There are many other medications shown effective. There are several antiseizure medications that are effective in the treatment of LGS, including felbamate, rufinamide, lamotrigine, topiramate, clobazam, cannabidiol, and others.
Side Effects
All seizure medications can be associated with fatigue and sedation. Other side effects are specific to certain medications and treatments. Speak to your doctor about side effects before deciding on treatment.
Speak to your doctor about medication options and their side effects.
Dietary Therapy
The ketogenic diet can be effective in LGS. It can reduce seizures by 50% in more than half of children. The diet is:
- High fat
- Adequate protein
- Low carbohydrate
There are various types of ketogenic diet. The classical diet is the strictest. It is used mostly in infants and toddlers. Milder versions include the modified-Atkins or low-glycemic-index diets. These are better options for school-aged children, teens, and adults. Dietary therapy should be prescribed and monitored by an experienced dietician.
Surgery
Corpus callosotomy surgery can help with atonic seizures in most LGS patients. This involves separating the brain tissue on the two sides of the brain. It may be used if atonic seizures persist despite medicine and diet therapies.
In rare cases, LGS is caused by a localized brain abnormality. In these cases, surgery on that tissue can lead to fewer or no seizures.
Neuromodulation
Other management issues
Children with LGS can often benefit from ongoing physical, occupational and speech therapy. In school they usually require an Individualized Education Plan (IEP). IEP’s allow the school curriculum to be targeted to their specific needs.
Given the high medical needs of persons with LGS, families often require some type of respite care. Working with a knowledgeable social worker is important to identify resources to support families.
Costs
A 2015 report showed that average yearly medical costs are about $64,000 for LGS. This number depends on insurance status. Hospitalizations and home health services are a big expense. Many medication options are generic. They are relatively inexpensive. Newer medications, such as cannabidiol, are more expensive. However, they are generally covered by insurance.
Sometimes, a therapy is denied insurance coverage at first. However, working with a healthcare provider to appeal the decision can help.
Resources
Pediatric Epilepsy Surgery Alliance
The Pediatric Epilepsy Surgery Alliance (formerly known as The Brain Recovery Project) enhances the lives of children who need neurosurgery to treat medication-resistant epilepsy. They empower families with research, support services, and impactful programs before, during, and after surgery. PESA’s programs include research-based, reliable information to help parents and caregivers understand when a child’s seizures are drug-resistant; the risks and dangers of seizures; the pros and cons of the various neurosurgeries to treat epilepsy; the medical, cognitive, and behavioral challenges a child may have throughout life; school, financial aid, and life care issues. PESA’s resources include a comprehensive website with downloadable guides, pre-recorded webinars, and virtual workshops; an informative YouTube channel with comprehensive information about epilepsy surgery and its effects; a private Facebook group (Education After Pediatric Epilepsy Surgery) with over 300 members; Power Hour (bi-monthly open forums and live virtual workshops on various topics); and free school training to help your child’s education team understand the impact of their epilepsy surgery in school. Their Peer Support Program will connect you with a parent who has been there. The Pediatric Epilepsy Surgery Alliance also hosts biennial family conferences and regional events that allow families to learn from experts, connect with other families, and form lifelong friendships. They also provide a travel scholarship of up to $1,000 to families in need to fund travel to a level 4 epilepsy center for a surgical evaluation.
In addition, PESA has resources for medical professionals to assist in helping clinicians help the parents of their patients find the resources they need after surgery. Educators and therapists will also find helpful resources and information, including videos, guides, and relevant research. Patients who have undergone surgery are encouraged to register with the Global Pediatric Epilepsy Surgery Registry to help set future research priorities.
LGS Foundation
The LGS Foundation’s mission is to improve the lives of individuals affected by Lennox-Gastaut syndrome (LGS) through research, family support programs, and education. The LGS Foundation also hosts a private LGS Facebook Group.
Child Neurology Foundation (CNF) solicits resources from the community to be included on this webpage through an application process. CNF reserves the right to remove entities at any time if information is deemed inappropriate or inconsistent with the mission, vision, and values of CNF.