Lennox-Gastaut syndrome (LGS) is a severe form of epilepsy associated with intractable seizures and impaired cognition. On inter-ictal electroencephalography (EEG), LGS is characterized by generalized epileptiform discharges including slow (1.5-2.5 Hz) spike-and-wave complexes and bursts of paroxysmal fast activity. Onset typically occurs between the ages of 2 and 8 and affects predominantly males. Aetiologies underlying LGS vary widely across patients, and include both genetic and acquired causes (e.g., diffuse brain damage following asphyxia, tuberous sclerosis, encephalitis or metabolic disorders). Prevalence varies between 1-10% of all childhood epilepsy. In 15-20% of patients, the cause of LGS remains unknown. Around 20% of patients develop LGS following infantile West syndrome.
Daily multiple seizures are found in LGS, often occurring nocturnally and thus undetected by parents or caregivers. Individual patients often show a variety of seizure types (including tonic, atonic, and atypical absence seizures). Tonic seizures, which cause patients to unpredictably stiffen and fall to the ground, are often associated with head injuries which can further worsen patients’ cognitive impairment. Atonic seizures (also called drop attacks, lasting between 1 and 4 seconds) cause head nods, loss of posture and sagging at the knees; 50% of patients experience one or more episodes of non-convulsive status epilepticus.
Therapy is challenging, with more than 80% of patients experiencing lifelong seizures and intellectual disability. Potentially effective anti-epileptic medications include Valproic acid and Rufinamide. The ketogenic diet may be an effective treatment option in some cases. In patients with a focal epileptogenic lesion visible on MRI, resective surgery can occasionally lead to seizure improvements. Other surgical options include vagus nerve stimulation (VNS), corpus callosotomy, and deep brain stimulation (DBS). Wearing a helmet is often demanding.