Electro-clinical spectrum of Absence epilepsy: A case series from India

Objective: To describe epidemiological, clinical, ictal and inter-ictal EEG profile of absence epilepsy Methods: Demographic, clinical and EEG details of children diagnosed with absence epilepsy between January 2018-December 2021 were analysed. Results: 51children were enrolled: childhood absence epilepsy (CAE) in 39, juvenile absence epilepsy (JAE) in 8, Jeavon’s syndrome (JS) and juvenile myoclonic epilepsy (JME) in two each. JME (150±8.49months) and JAE (100.75±26.87months) had later age of onset than CAE (63.15±29.01months) and JS (72±16.97months). Ictal motor phenomena were commonly seen: eyelid myoclonia (56.41%), shoulder myoclonia (28.2%), neck myoclonia (20.5%), automatisms (12.8%), perioral myoclonia (7.69%) and were commonly seen in CAE. Both ictal and inter-ictal polyspikes were more common in JS (100%, 100%) and JME (100%, 100%) than JAE (62.5%, 62.5%) and least common in CAE (33.33%, 41.03%). Unilateral focal inter-ictal epileptic discharges (IED) was seen in 1 patient with JS, and bilateral focal IED were seen in upto 50% patients of CAE and JAE. Parieto-occipital predominance of IED was seen in 1 case each of JS and CAE while rest showed fronto-central predominance. Ictal EEG showed higher median spike frequency for JS (4Hz), JME (4.5Hz) than CAE (3Hz) and JAE (Hz). Photosensitivity was seen in both cases of JS, and one child with CAE. Hyperventilation activated IED in JS (100%), CAE (74.36%), JAE (62.5%) and JME (50%). 65% with CAE showed good response with Valproate and 42% with Ethosuximide. Conclusion: Motor phenomena are quite common in children with absence epilepsy. Clinical and electrographic features help differentiate different absence epilepsy syndromes.
Keywords: Absence epilepsy, CAE, JAE, Jeavon's, JME