Crossing the lines between epilepsy syndromes: a myoclonic epilepsy variant with prominent eyelid myoclonia and atonic components.

Accurate diagnosis of a distinct epilepsy syndrome is based on well-defined electroclinical features that differentiate separate nosological entities. In clinical practice, however, syndromes may overlap and cases may present with unusual manifestations posing a diagnostic challenge. This heterogeneity has been documented in several cases presenting with eyelid myoclonia with or without absences (EMA) diagnosed either as Jeavons syndrome (JS) variants or as genetic generalised epilepsies defined by the presence of this unique clinical entity. The hallmark of JS is the triad: (1) eyelid myoclonia with or without absences, (2) eye closure-induced paroxysms, and (3) photosensitivity. The presence of massive myoclonus, intellectual disability, or slowing of the EEG background are not typical features of the syndrome and may cause delay in making the correct diagnosis. Adding to the variability of clinical features, we describe two female paediatric patients with probable genetic epilepsy who presented with EMA but demonstrated clear atypical features, such as prominent myoclonic seizures, atonic components on video-EEG, and cognitive impairment. We also note the presence of interictal and ictal posterior discharges during eyelid myoclonia in one, supporting similar previous observations leading to consideration of EMA as an occipital cortex-initiated seizure activity. [Published with video sequences on www.epilepticdisorders.com].

Epilepsy with myoclonic-atonic seizures (Doose syndrome): When video-EEG polygraphy holds the key to syndrome diagnosis.

An electroclinical epilepsy syndrome diagnosis enables physicians to predict outcomes as well as select appropriate treatment options. We report a child who presented with reflex myoclonus at the age of 9 months and was initially diagnosed with myoclonic epilepsy in infancy. After 9 years of medically resistant myoclonic seizures, extensive investigations, and emerging learning difficulties, she was referred for video-telemetry to characterize her seizures in an attempt to make a syndromic diagnosis. A three-day video-telemetry assessment was performed to document seizures. Neck and deltoid EMG channels were applied from the onset of the recording. Frequent generalized bursts of 3- to 5-Hz spike/polyspike and slow wave discharges, associated with clinical manifestations, mostly myoclonic seizures, were noted. In addition, definite atonic components were noted on the neck EMG as well as the deltoids associated with the slow component of the ictal discharges. The EEG and polygraphy findings are suggestive of a generalized epilepsy characterized by predominantly myoclonic seizures with atonic components. This raises the possibility whether a variant of epilepsy with myoclonic-atonic seizures (Doose syndrome) may be the underlying diagnosis for this girl. A trial of the ketogenic diet would therefore be considered as an option in her future management in view of its beneficial effect in this condition.