Signs and Symptoms of LGS

Many LGS Associated Disorders exist, including issues with sleep, behavior, movement, feeding, toileting, communication, and many others.

Age of Onset

LGS usually develops in the preschool years. LGS always evolves from seizures and very commonly evolves from other epilepsy syndromes such as infantile spasms or West Syndrome. It usually takes time for all features of LGS to appear. Therefore, according to experts, it can be challenging to accurately diagnose the disease before age two-and-a-half.

Seizure Types Seen in LGS

Persons with LGS have several types of seizures. These can include:

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 during 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 an 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 is followed by a period of confusion. These seizures can progress into generalized tonic-clonic seizures.
Tonic-clonic seizure. These consist of generalized stiffening and rhythmic shaking. Seizures often change in children with LGS as they grow and develop.

LGS is a lifelong neurodevelopmental disorder and seizures are the main feature, are frequent, and are debilitating. Therapies may help. However, they do not completely stop seizures. Persons with LGS have varying degrees of intellectual disability and behavioral issues. Some struggle with aggression. Some meet autism spectrum disorder criteria.

Intellectual Disability

Persons with LGS nearly always have intellectual disabilities. 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

Developmental delay and/or intellectual disability occur in most with LGS. Delays in development are not always present at the start of LGS and are not required for the diagnosis to be made.

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.

Sleep Problems

Sleep problems are common in those with LGS. These include trouble falling asleep, staying asleep, waking up, frequent nighttime seizures, and other issues.

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.

The Natural History of LGS — Anne Berg, PhD

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