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Incidence

Idiopatic condition. Jeavons syndrome appears to be genetically determined. The syndrome occurs slightly more frequently in females than in males. Prevalence is unknown. Jeavons syndrome may represent around 7-8% of all idiophatic generalized epilepsies.

Clinical Characteristics

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. Eyelid myoclonia is the principal clinical feature and may or may not be associated with brief (less than 6 seconds) absences. During eyelid myoclonia the eyelids or eyes may quickly roll or jerk backwards and upwards. The etiology is unknown but Jeavons syndrome appears to be genetically determined. It is considered an epileptic syndrome. Eye closure in the presence of uninterrupted light is the major triggering factor. Intermittent photic stimulation potentiates the effect of eye closure and is capable of inducing seizures when eyes are open or closed. Photosensitivity declines with age, whereas eye closure usually remains a life-long precipitating factor. The EEG is the single most important diagnostic procedure. The EEG is dominated with high amplitude discharges of spike-and-slow waves at 3 to 6 Hz. They are brief (1 to 5 seconds) and are commonly associated with clinical manifestations of eyelid myoclonia of varying severity. They often occur immediately after closing the eyes in an illuminated recording room. They are eliminated in total darkness. EEG discharges are also enhanced by hyperventilation. Eyelid myoclonic status epilepticus has been reported. Generalized tonic-clonic seizures occur in most patients, they are infrequent. Mental development is usually normal but mild to moderate intellectual deficit has been reported in few cases. The seizures in Jeavons syndrome usually respond well to antiepileptic treatment, with medications used for generalized idiopathic epilepsies with absences and myoclonias. Valproic acid, benzodiazepines, levetiracetam, lamotrigine, and ethosuximide may help to control most of the seizures. 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. Carbamazepine, vigabatrin, and tiagabine are contra-indicated, and the same may be true for phenytoin. They can worsen seizures.

Precipitants

As with most seizures, sleep deprivation or withdrawal of treatment may trigger seizures or worsen them. Eye closure in the presence of uninterrupted light is the major triggering factor. Intermittent photic stimulation potentiates the effect of eye closure and is capable of inducing seizures when eyes are open or closed. Eye closure usually remains a life-long precipitating factor. The seizures may even be triggered by simply going out of a dark room into sunlight.

Provocation Tests

Eye closure in the presence of uninterrupted light is the major triggering factor. Intermittent photic stimulation potentiates the effect of eye closure and is capable of inducing seizures when eyes are open or closed. Photosensitivity declines with age, whereas eye closure usually remains a life-long precipitating factor.

Diagnostic Procedures

It is a clinical-EEG diagnosis. The EEG is the single most important diagnostic procedure. 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. The EEG is dominated with high amplitude discharges of spike-and-waves at 3 to 6 Hz. They are brief (1 to 5 seconds) and are commonly associated with clinical manifestations of eyelid myoclonia of varying severity. They often occur immediately after closing the eyes in an illuminated recording room. They are eliminated in total darkness. EEG discharges are also enhanced by hyperventilation.