EMEA, Eyelid myoclonia with and without absences
Jeavons syndrome is an idiopathic generalized form of reflex epilepsy characterized by childhood onset, unique seizure manifestations, striking light sensitivity, and possible occurrence of generalized tonic-clonic seizures. Prevalence is unknown but Jeavons syndrome appears to represent around 7-8% of all idiophatic generalized epilepsies (IGEs). Onset occurs in childhood, with a peak at 6-8 years of age, and the syndrome is slightly more frequent in females than in males. Eyelid myoclonia is the principle clinical feature and may or may not be associated with brief (less than 6s) absences. Eye closure in the presence of uninterrupted light is the major triggering factor. Eyelid myoclonic status epilepticus is reported in up to one fifth of the patients and self-induction, although rare, has been described. Generalized tonic-clonic seizures occur in most patients, but the frequency of the seizures is low. Mental development is usually normal but mild to moderate intellectual deficit has been reported in some cases. The etiology is unknown but Jeavons syndrome appears to be genetically determined: the majority of reported patients have a family history of IGE and a few cases of affected twins have been reported. Eyelid myoclonia is a highly distinctive seizure type and is strongly suggestive of Jeavons syndrome. Video-electroencephalography (video-EEG) is the only procedure required for diagnosis and reveals eye closure-related generalized paroxysmal activity. Thus, in patients with eyelid myoclonia with or without absences, associated with photosensitivity and EEG discharges triggered by eye closure, the diagnosis of Jeavons syndrome is straightforward. However, other forms of idiopathic, cryptogenic, and symptomatic epilepsy featuring eyelid myoclonia or eye closure sensitivity (juvenile myoclonic epilepsy, juvenile absence epilepsy, and idiopathic photosensitive occipital lobe epilepsy; see these terms) may also be considered in the differential diagnosis. Misdiagnosis of eyelid myoclonia as a facial tic has also been reported. The seizures in Jeavons syndrome usually respond well to antiepileptic treatment, with antimyoclonic drugs (valproate, benzodiazepines, levetiracetam, and zonisamide) showing the highest level of efficacy and generally allowing good seizure control. However, polytherapy is often needed and some cases may be drug-resistant. The overall prognosis is good, although Jeavons syndrome is usually a lifelong condition.