Jeavons Syndrome
Jeavons Syndrome, also known as Eyelid Myoclonia with Absences (EMA) is a genetic generalized epilepsy characterized by a triad of eyelid myoclonia, photosensitivity, and brief absence seizures. It is a distinct, well-defined epilepsy syndrome recognized by the ILAE.
Presentation and Clinical Features
Age and Demographics: The onset is typically in early childhood or preschool years (around 2 to 4 years of age) and is more common in girls.
Core Triad of Symptoms:
Eyelid Myoclonia (EM): This is the hallmark feature. It consists of brief, rapid, involuntary jerking or flickering of the eyelids, often with an upward deviation of the eyes and a subtle backward head jerk. These episodes are very brief, typically lasting only 2 to 3 seconds. They can occur in clusters and may be mistaken for tics.
Absence Seizures: These are brief and are directly associated with the eyelid myoclonia. They are often so short (less than 6 seconds) that they can be easily missed. Consciousness is briefly impaired.
Photosensitivity: Photosensitivity is a universal feature of Jeavons Syndrome. The eyelid myoclonia and absences are reliably triggered by photic stimulation, such as flashing lights, or even by simple eye closure or the transition from a dark to a light environment.
Other Seizures: Some patients may also experience generalized tonic-clonic seizures (GTCS), although this is less common than in JME. The GTCS are often triggered by the same factors that trigger the eyelid myoclonia, particularly sleep deprivation and photic stimulation.
Development and Cognition: Most individuals with Jeavons Syndrome have normal cognitive development and intelligence.
Investigation
EEG: An EEG is essential for diagnosis. It is almost always abnormal and shows characteristic findings, including bursts of fast generalized spike-and-wave or polyspike-and-wave discharges.
Activation: The EEG abnormalities are consistently and powerfully enhanced by photic stimulation and eye closure, which is a key diagnostic clue.
Video-EEG: A video-EEG is highly recommended to capture the brief, subtle seizures and differentiate them from non-epileptic events like tics.
Neuroimaging: A brain MRI is not routinely needed as Jeavons Syndrome is a functional epilepsy, not a structural one. It should only be considered if there are atypical findings.
Management
Treatment Goal: The primary goal is to achieve seizure control and improve the patient’s quality of life, although complete seizure freedom can be challenging to achieve.
First-Line Medications:
Valproate is the most effective drug for controlling all seizure types in Jeavons Syndrome.
Levetiracetam is a strong first-line alternative, especially due to its good efficacy and favorable side-effect profile.
Lamotrigine can also be effective for some patients but may be less potent.
Ethosuximide can be added to help control absences but is not effective against GTCS.
Medications to Avoid:
Carbamazepine, Oxcarbazepine, and Phenytoin can worsen myoclonic seizures and are contraindicated in this syndrome.
Non-Pharmacological Management: Patients and their families must be educated about avoiding triggers like sleep deprivation, alcohol, and flashing lights. The use of tinted lenses or special eyewear may help reduce photosensitivity.
Prognosis: Jeavons Syndrome is considered a lifelong condition, and medication is often needed for the long term.