Long‐Term Seizure Outcome in 74 Patients with Lennox–Gastaut Syndrome: Effects of Incorporating MRI Head Imaging in Defining the Cryptogenic Subgroup

Abstract

Summary:Purpose: To determine if using more stringent criteria for cryptogenic Lennox-Gastaut syndrome (LGS) would result in an improved prognosis for that group. Cryptogenic, symptomatic, and non-cryptogenic LGS patients without etiology (indeterminate) were compared with respect to seizure and cognitive outcome.Methods: Retrospective chart review was performed on 245 patients seen at the Mayo Clinic Rochester from 1976 to 1997, with a diagnosis of either LGS or slow spike wave on EEG.LGS was confirmed in 107 (64 male, 43 female) patients. This group was divided into cryptogenic, symptomatic, and indeterminate groups containing 23,47, and 37 patients, respectively. In this study, cryptogenic patients all had normal development before onset of LGS, absence of dysmorphic features, normal neurologic examination, and normal magnetic resonance (MRI) brain imaging. Of the 107 patients, 74 had 2 3 years of follow-up. Results:LGS onset in the 107 patients occurred at a median age of 4.0 years (range, 0.6-28.9 years). When last seen, 63% of those with symptomatic LGS had more than three seizures a day compared with 50% of cryptogenic and 34% of indeterminate patients. The most common seizure types were tonic (77%), atypical absence (61 %), and generalized tonic-clonic (56%). Only three patients, all part of the indeterminate group, were seizure free at last follow-up.Conclusions: Using stringent criteria in defining the cryptogenic subgroup resulted in no significant difference in seizure outcome. Individuals with a normal cognitive outcome did not segregate into one etiologic subgroup, but did have LGS onset at an older age.

Predicting antiepileptic drug response in children with epilepsy

“…At follow-up of at least 10 years, 5-13% of individuals were in remission and 8% were not mentally retarded. Patients with cryptogenic LGS had a better cognitive outcome compared with patients who had symptomatic LGS [38], but another study reported no difference between the groups [39]. …”

“…LGS is often (in 13-65% of cases), and in cases of symptomatic etiology in particular, a continuation of West syndrome [36,38,39]. However, as shown in a communitybased study, prenatal or perinatal abnormalities are not necessarily in correlation with the severity of epilepsy [40].…”

Epileptic Encephalopathies: New Genes and New Pathways

“…The use of corticosteroids has also been described in LKS, Ohtahara syndrome and in LGS, particularly for the treatment of periods of nonconvulsive status epilepticus. Only a minority of patients with EE achieve seizure freedom [126,127]. The main goal of pharmacotherapy is a reduction in the frequency and severity of seizures to improve quality of life [28].…”

Rufinamide in patients with Lennox-Gastaut syndrome

“…2 The majority of patients with symptomatic LGS experience more than 3 seizures per day. 3 The seizure types that are most frequently observed in LGS are tonic, atypical absence, atonic, myoclonic, generalized tonic-clonic, and focal onset (previously referred to as partial onset) seizures. [3][4][5] Patients with LGS experience frequent seizures, usually during sleep, with 10-20 Hz fast rhythms.…”

“…2 The median age of LGS onset is ~4 years. 3 Many patients (46.9%, by one estimate) who develop LGS during childhood continue to present the complete disease profile into adulthood. 10 For the majority of patients with LGS, seizures remain difficult to treat, [11][12][13] and most of the patients cannot live independently as adults.…”