Lennox Gastaut Syndrome (LGS) is a severe childhood epileptic encephalopathy characterized by multiple seizure types including tonic-atonic seizures. It typically has an onset between ages 3-8 and causes cognitive impairment. Treatment involves identifying the syndrome and selecting effective therapies like clobazam, felbamate, lamotrigine, and rufinamide while avoiding treatments that can worsen seizures. The ketogenic diet and vagus nerve stimulation may also provide benefit.

1. Lennox Gastaut
Syndrome
Enrique Feoli MD
North East Regional Epilepsy Group

2. Goals
 Understand the definition of LGS
 Outline the clinical presentation of LGS
 Compare the different medications
available to treat LGS
 Develop a rational treatment approach for
LGS

3. Syndrome types in different age groups
Infancy;
-West Syndrome
-Ohtahara Synd.
-Dravet Syndrome
Late Childhood (5-10y)
-Absence Epilepsy
-Landau-K syndrome
-Benign Rolandic E.
Early Childhood (1-5y)
-LGS
-Febrile Seizures
Adolescence
-JME
-Juvenile Absence epilepsy

4. LGS Prevalence and Incidence
 Prevalence is 1 to 10 % of all childhood
epilepsy
 Incidence rate for LGS of all new onset
epilepsies is 0.6 %

5. Etiology
 Brain malformations
 Hypoxic-ischemic brain injury
 Meningitis &Encephalitis/Congenital infections
 Neurocutaneous syndromes-Tuberous sclerosis
 Trauma
 Brain tumors
 Cortical dysplasia/Bilateral perisylvian syndrome
 17-30% with LGS will have history of infantile spasms.
 Few have metabolic issues such as Leigh’s
encephalomyelopathy or Channelopathies.

6. LGS Diagnosis; Pediatrics
 -Onset 3 to 8 years of age
 -Seizures type;
-Tonic-atonic drop attacks
-Tonic clonic
- Atypical absences;
Gradual onset and termination
Behavioral pause/stare (30 + seconds)
Clonic activity

7. LGS Diagnosis; Pediatrics Cont
 May present as non-convulsive status
epilepticus in 50 to 75 % of patients
 -Cognitive impairment and developmental delay.
 -EEG; irregular, gneneralized 2 to 2 ½ Hz spikes
and wave pattern

9. LGS Diagnosis; adult
 Onset 4 to 8 years of age
 Cognitive impairment and developmental delay
 Seizures Type;
Childhood onset tonic-atonic drop attacks
Complex partial/frontal lobe seizures
Seizures; arms asymetrically elevated
Vocalization
5 to 20 seconds duration

10. LGS Diagnosis; adult
EEG (variable)
- Background; normal (rare) to diffuse
slowing
- Ictal; diffuse attenuation
generalized irregular 2 to 2 ½ Hz
spikes/wave generalized might lateralized
without clear focal findings.

13. LGS treatment
 Antiepileptic drugs
 Surgery;
-Vagus Nerve stimulator VNS shows a 24%–
42% global seizure reduction. Comparable
outcome to corpus callosotomy without
invasive surgery (a)
-Corpus callosotomy
most beneficial for atonic seizures
 Diet; Ketogenic, Modified Atkins diet.
a-Lancman et al. AES 2011 Abstract 3.313

15. LGS treatment with AEDs
 Effective in randomized, double blind
placebo controlled trial, approved by FDA;
Clobazam, Felbamate,Lamotrigine,
Rufinamide, Topiramate.
 Effective in open level trials
Vigabatrin, Zonisamide

16. LGS treatment with AEDs
 Often used
Valproic acid, Clonazepam
 Limited utility (may exacerbate seizures)
CBZ, Phenobarbital, Primidone

18. Aeds Additive effects
 Post-hoc sub analysis of the CLB trial;
Evaluated drop seizures rate from baseline
to 12 week in patient receiving CLB with
LTG or VPA.
Average reduction in drop seizures was
grater for either combination vs placebo.
Efficacy was dose dependent

19. What Medication to use first
 Based on Syndrome
 Based on gender
 Based on side effects
Choices; Depakote, Topiramate,
Lamotrigine, Felbamate.

20. What medication to use Next
 Based on the first medicine
 Based on Additive effect
 Based on side effects
Options; Rufinamide, Zonisamide,
Vigabatrin, same as the previous list,
Benzodiazepines, Levetiracetam

21. Diet for LGS
 Ketogenic Diet
 Modified Atkins diet for Epilepsy
 Low glycemic index diet

22. Ketogenic diet
 A treatment option for epilepsy (LGS)
 A very strict diet that involves fluid
restriction, high fat and low carbohydrate +
protein intake.
 The goal: alter the body’s fuel source from
glucose to fat.

23. History
 The basis of the diet – fasting
 Devised in the 1920’s at Johns Hopkins
University School of Medicine.
 Popularity faded in the 40’s and 50’s when new
anticonvulsant drugs were discovered
 Resurgence recently because, among others, of
the TV movie based on Charlie Abrahams

24. Who is a candidate
 Children – usually 2-10 years of age
 Most effective in kids with “drop” type
seizures
 The children considered have at least 3
seizures/week
 The antiepileptic medication is not
working.

25. Efficacy
 20-30% – seizures were completely
controlled
 50-70% - seizure frequency decreased by
50%
 20-30% - not effective

26. Modified Atkins
 Absence of protein, fluid, or calorie
restriction
 64% fat
 30% protein
 6% carbohydrate (10 to 20% on regular
Atkins diet)

27. Modified Atkins
 The modified Atkins diet is a modification
of the traditional ketogenic
 Foods are not weighed and measured, but
carbohydrate counts are monitored by
patients and parents.
 It is started outside of the hospital

28. Modified Atkins
Is it Effective?
 60 to 70 % >50% improvement,
 20 to 30 % >90% improvement
 5 to 10 % seizure free

29. Surgical Options
 Vagus Nerve stimulator VNS shows a
24%–42% global seizure reduction.
Comparable outcome to corpus
callosotomy without invasive surgery.
 Corpus callosotomy
most beneficial for atonic seizures

30. Summary
 Lennox Gastaut Syndrome
 Difficult epileptic encephalopathy
 Onset in childhood
 Persist into adult life
 Optimal Treatment
 Requires identification of the syndrome
 Selection of effective therapy
 Ovoid treatments that exacerbate seizures