Diagnosis of Lennox-Gastaut syndrome and strategies for early recognition

ABSTRACT

Introduction

Lennox Gastaut syndrome (LGS) as an electroclinical diagnosis has been utilized as a clinical entity for more than 70 years. However, with the recognition of other distinct electroclinical epilepsy syndromes, no consistent single etiology, and the variability of criteria used in clinical trials, the clinical utility of such a diagnosis has been questioned. Recently, the International League Against Epilepsy for the first time defined diagnostic criteria for epilepsy syndromes, thereby allowing consistent language and inclusion criteria to be utilized.

Areas covered

Recent diagnostic criteria for syndrome diagnosis are explored as defined by the International League Against Epilepsy, with further literature reviewed to highlight relevant features, and differential diagnosis explored.

Expert Opinion

Developmental and Epileptic Encephalopathy (DEE) is an overall term that may be descriptive of many different epilepsies, most of early onset, whether electroclinically or etiologically defined, of which LGS is one. Although we have moved forward in defining an increasing number of etiologically specific syndromes, this to date remains a minority of the DEEs. Although there is progress with precision medicine targeted at specific causes, the term LGS still remains useful as a diagnosis in defining treatment options, as well as overall prognosis.

KEYWORDS:

• Lennox Gastaut syndrome
• DEE
• encephalopathy
• early diagnosis
• targeted therapy
• diagnostic challenge
• syndrome-in-evolution

Article highlights

• Lennox Gastaut Syndrome (LGS) has been recognized as a clinical entity for >70years

• Increased recognition of more tightly defined electroclinical syndromes, and no specific aetiology of LGS  have raised the question as to whether the definition remains useful

• Diagnostic criteria as defined by the International League Against Epilepsy for well-established epilepsy syndromes has allowed more specific definition

• The presence of tonic seizures, with at least one additional seizure type remain mandatory for the diagnosis, along with specific EEG features of generalized slow spike-and-wave complexes of <2.5 Hz (or history of this finding on prior EEG) and generalized paroxysmal fast activity in sleep (or history of this finding on prior EEG)

• The differential diagnosis includes other well-defined electroclinical syndromes, and specific etiologies that are important to recognise

• The use of the term LGS remains useful especially for those where etiology may not be clear, in defining treatment options, as well as overall prognosis

Declaration of interest

JH Cross has received grants from Stoke Therapeutics, Ultragenyx, UCB, National Institute for Health and Care Research (NIHR), Great Ormond Street Hospital Children’s Charity (GOSHCC), LifeARC, the Waterloo Foundation, and the Action Medical Research. JH Cross has also received honoraria payments from Biocodex, Nutricia, Jazz Pharmaceuticals, Takeda and UCB, which have been sent to University College London. S Pujar has received honoraria payments from UCB. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.