The 2017 and 2022 ILAE epilepsy classification systems identify needs and opportunities in care: A paediatric hospital-based study.

OBJECTIVES: There is a paucity of studies reporting the epilepsy spectrum using the 2017 and 2022 ILAE classification systems in everyday clinical practice. To identify gaps and opportunities in care we evaluated a hospital-based cohort applying these epilepsy classification systems, including aetiology and co-morbidity, and the utility of molecular genetic diagnosis to identify available precision therapies. METHODS: Cross sectional retrospective study of all children with epilepsy (≤16 years) attending University Hospital Galway (2017-2022). Data collection and analysis of each case was standardised to ensure a systematic approach and application of the recent ILAE categorisation and terminology (2017 and 2022). Ethics approval was obtained. RESULTS: Among 356 children, epilepsy was classified as focal (46.1 %), generalised (38.8 %), combined (6.2 %), and unknown (9 %). Epilepsy syndrome was determined in 145/356 (40.7 %), comprising 24 different syndromes, most commonly SeLECTS (9 %), CAE (7 %), JAE (6.2 %) and IESS (5.9 %). New aetiology-specific syndromes were identified (e.g. CDKL5-DEE). Molecular diagnosis was confirmed in 19.9 % (n = 71) which encompassed monogenic (13.8 %) and chromosomopathy/CNV (6.2 %). There was an additional 35.7 % (n = 127) of patients who had a presumed genetic aetiology of epilepsy. Remaining aetiology included structural (18.8 %, n = 67), infectious (2 %, n = 7), metabolic (1.7 %, n = 6) and unknown (30.3 %, n = 108). Encephalopathy categorisation was determined in 182 patients (DE in 38.8 %; DEE in a further 11.8 %) associated with a range of co-morbidities categorised as global delay (29.2 %, n = 104), severe neurological impairment (16.3 %, n = 58), and ASD (14.6 %, n = 52). Molecular-based "precision therapy" was deemed available in 21/356 (5.9 %) patients, with "molecular precision" approach utilised in 13/356 (3.7 %), and some benefit noted in 6/356 (1.7 %) of overall cohort or 6/71 (8.5 %) of the molecular cohort. CONCLUSION: Applying the latest ILAE epilepsy classification systems allow comparison across settings and identifies a major neuro-developmental co-morbidity rate and a large genetic aetiology. We identified very few meaningful molecular-based disease modifying "precision therapies". There is a monumental gap between aetiological identification, and impact of meaningful therapies, thus the new 2017/2022 classification clearly identifies the major challenges in the provision of routine epilepsy care.

Epileptic dyskinetic encephalopathy in KBG syndrome: Expansion of the phenotype.

KBG syndrome is characterised by developmental delay, dental (macrodontia of upper central incisors), craniofacial and skeletal anomalies. Since the identification of variants in the gene (ANKRD11) responsible for KBG syndrome, wider phenotypes are emerging. While there is phenotypic variability within many features of KBG syndrome, epilepsy is not usually markedly severe and movement disorders largely undocumented. Here we describe a novel early onset phenotype of dyskinetic epileptic encephalopathy in a male, who presented during infancy with a florid hyperkinetic movement disorder and developmental regression. Initially he had epileptic spasms and tonic seizures, and EEGs revealed a modified hypsarrhythmia. The epilepsy phenotype evolved to Lennox-Gastaut syndrome with seizures resistant to multiple anti-seizure therapies and the movement disorder evolved to choreoathetosis of limbs and head with oro-lingual dyskinesias. Previous extensive neurometabolic and imaging investigations, including panel-based exome sequencing were unremarkable. Later trio exome sequencing identified a de novo pathogenic heterozygous frameshift deletion of ANKRD11 (c.6792delC; p.Ala2265Profs*72). Review of the literature did not identify any individuals with such a hyperkinetic movement disorder presentation in combination with early-onset epileptic encephalopathy. This report expands the phenotype of ANKRD11-related KBG syndrome to include epileptic dyskinetic encephalopathy.