myoclonia

Attacks of myoclonia are more common in the arms than the legs.

Instead, only 'eyelid myoclonia' has been accepted as an "absence seizure with special features".

Eyelid myoclonia is the defining seizure type of Jeavons syndrome.

Eyelid myoclonia is a seizure and not an attempt for self-induced seizures.

These movements are very different from the normal spasms, called hypnic myoclonia, that we often experience initially while trying to fall asleep.

Nevertheless, eyelid myoclonia is often misdiagnosed as facial tics, sometimes for many years.

There is a tendency for photosensitivity to disappear in middle age, but eyelid myoclonia persists.

Occasionally myoclonia and opsoclonus may occur.

This may be associated with or followed by mild impairment of consciousness (eyelid myoclonia with absences).

The diagnosis of Jeavons syndrome is simple because the characteristic eyelid myoclonia, if seen once, will never be forgotten or confused with other conditions.

Eyelid myoclonia (with and without absences)

Video-EEG is the single most important procedure for the diagnosis of eyelid myoclonia with or without absences.

Eyelid myoclonia of varying severity often occurs during these EEG discharges.

Between one and four years of age, children develop other seizure types including atypical absence, eyelid myoclonia and non-convulsive seizures.

Many may notice the feeling of falling during this stage of sleep, which may cause a sudden muscle contraction (called hypnic myoclonia).

Intermittent photic stimulation may precipitate or facilitate absence seizures; eyelid myoclonia is a common clinical feature.

It consists of repetitive and discontinuous episodes of eyelid myoclonia with mild absence, rather than continuous non- convulsive absence status epilepticus.

Eyelid myoclonia with or without absences is a form of epileptic seizure manifesting with myoclonic jerks of the eyelids with or without a brief absence.

Other proposed syndromes are Jeavons syndrome (eyelid myoclonia with absences) and genetic generalised epilepsy with phantom absences Precipitating factors of absence seizures.

It is one of the most distinctive reflex syndromes of idiopathic generalized epilepsy characterized by the triad of eyelid myoclonia with and without absences, eye-closure-induced seizures, EEG paroxysms, or both, and photosensitivity.

Eyelid myoclonia consists of marked jerking of the eyelids often associated with jerky upwards deviation of the eyeballs and retropulsion of the head (eyelid myoclonia without absences).

The symptom/seizure of eyelid myoclonia alone is not sufficient to characterise Jeavons syndrome, as it may also occur in symptomatic and cryptogenic epilepsies, which are betrayed by developmental delay, learning difficulties, neurological deficits, and abnormal MRI and background EEG.