Eyelid Myoclonia and Absence

Athanasios Covanis

Neurology Department, The Childrens Hospital “Agia Sophia,” Goudi, Athens, Greece

Introduction

Jeavons syndrome or the syndrome of eyelid myoclonia and absence is a type of photosensitive epilepsy. In the literature it is usually included under myoclonic epilepsies, absences or even reflex epilepsies. Although “eyelid myoclonia and absences” (ELMA) has a number of characteristic clinical features that have been stressed by many authors the last decade, it is still underdiagnosed.

Jeavons in 1977 first described ELMA as a separate type of photosensitive epilepsy with this quotation: Eyelid myoclonia and absences show a marked jerking of the eyelids immediately after eye closure and there is an associated brief spike-and-wave activity. The eyelid movement is like rapid blinking and the eyes deviate upwards, in contrast to the very slight flicker of eyelids that may be seen in a typical absence in which the eyes look straight ahead. Brief absences may occur spontaneously and are accompanied by 3 cycles per second spike-and-wave discharges. The spike-and-wave discharges seen immediately after eye closure do not occur in the dark. Their presence in the routine EEG is a very reliable warning that abnormality will be evoked by photic stimulation (1). In 1982 Jeavons changed the term from eyelid myoclonia and absences to eyelid myoclonia with absences (2), which was a mistake as he later admitted (3). The term “eyelid myoclonia with absences” implies that an absence is induced by eye closure, whereas, in fact, absences also occur independently of eye closure, often being induced by hyperventilation (3) and intermittent photic stimulation (IPS).

In typical cases, there is marked jerking of the eyelids, which is more pronounced in bright sunlight and some children regarded as having self-induced epilepsy (4,5,6) appear to have eyelid myoclonia. Binnie et al (1980) commented on the need for prolonged EEG recording for the diagnosis and that eye closure on command failed to induce eyelid myoclonia. In our experience, in all patients, the diagnosis is easily made during routine sleep–wake electroencephalograms (EEG) and, in all children, eye closure on command induces eyelid myoclonia. Following the description of Jeavons, more authors have identified ELMA as a separate entity (7,8,9,10,11,12,13,14). Therapy is less effective than in other photosensitive epilepsies (7).

The classification of epilepsies and epileptic syndromes in 1989 (15) did not include ELMA and the recent diagnostic scheme for people with epileptic seizures and with epilepsies has accepted eyelid myoclonia with or without absences as a new seizure type (16).

Definition

Eyelid myoclonia and absences is a form of idiopathic generalized epilepsy (IGE) with characteristic clinical and EEG features, which comply with the definition of an epileptic syndrome called “Jeavons Syndrome.” The combination of clinical and EEG phenomena, which follow eye closure, are unique and pathognomonic of ELMA: In a previous normal school age child, eye closure in the light induces eyelid flicker, flutter, or jerking in association with generalized EEG discharges. The eyes may open and stare or the eyelids open retract and jerk with an upward deviation of gaze (but never to the side). The discharges are invariably evoked during IPS. This type of discharge does not occur in the dark. The concomitant impairment of consciousness, conspicuous or inconspicuous, is relevant to the duration of the generalized discharge. Myoclonic jerks other than eyelid and generalized tonic–clonic seizures do occur. Females predominate in this condition.

Epidemiology

Prevalence

In 1982, we reported a prevalence of 7.3% among IGE (7). According to our unpublished data, ELMA represents 2.5% of all epilepsies and 11% of IGE. Similar prevalence of 2.7% and 12.9% correspondingly, is reported in adults (13). ELMA is as common as juvenile myoclonic epilepsy (JME), but is underdiagnosed and the mild forms underreported.

Sex Distribution and Age of Onset

As with most of the photosensitive epilepsies, eyelid myoclonia is more common in females. Two studies (7,11) reported a female to male ratio of 3.7:1 and 4:1, respectively. In another study (13) of 11 patients, all were female.

The age of onset is similar to that of childhood absence epilepsy (CAE) and earlier than most photosensitive epilepsies. An onset ranging from 2 to 14 years (mean 5.8 ± 2.3 y) has been reported (7,11,13). In our experience, based on 50 patients with ELMA, the female to male ratio is 3.2:1 and the age of onset from 2.5 to 14 years (mean 7.2 ± 2.7 y).

Etiology

Eyelid myoclonia and absences is an idiopathic generalized photosensitive epilepsy syndrome with characteristic clinical and EEG features. In contrast to the other syndromes, which have myoclonic jerks, absences, and generalized tonic–clonic seizures in different proportion in their phenotype, eyelid jerking is a unique feature of this syndrome. There is a familial preponderance and the concordance rate is high (17). In our population of 50 ELMA patients, the family history was positive for epilepsy in 28%. Among them there were nine families of probands with Jeavons syndrome and first-degree relatives with ELMA or IGE. The concordance rate was 78%. From these families, it is difficult to be specific about the mode of inheritance, although they suggest some dominant alleles.

Pathophysiology

Jeavons syndrome is genetically determined and expressed in childhood. In order for the genetic predisposition to be manifest clinically, it needs the simultaneous operation of two additional factors: the spontaneous or on-command slow eye closure and the visual light input. Eye closure is a brief, less than a 3-msec phase during which the upper and lower eyelids touch. The hyperexcitable cortical area alone can generate spontaneous generalized discharges without apparent clinical phenomena, e.g., during sleep. A strong intermittent light input in a predisposed person without eye closure, can induce discharges, which may be associated with absences, e.g., during IPS with the eyes open. Eye closure in a predisposed person cannot generate discharges without light input, e.g., in total darkness. The eyelid movements are under voluntary, automatic, reflex, autonomic, and emotional control. The cortical area representing eye closure lies in the precentral gyrus adjacent to the hand area (18), which is involved in self-induced epilepsy. The “cortical factor” involved in spontaneous or on-command eye closure seems to be important as passive slow eye closure in the presence of light does not induce discharges or eyelid myoclonia in a predisposed person, except in some cases of early onset. Blinking, which is a brainstem reflex, does not trigger clinical and EEG phenomena. Similar observations are observed in self-induced epilepsy where the cortical hand area is involved. EEG and clinical phenomena are induced by hand waving, voluntary or on-command in the presence of light. Passive hand waving or waving the examiners hand in front of the eye(s) in the presence of light does not induce discharges and clinical phenomena in a predisposed person.

Some authors believe that in ELMA there is a malfunction of alpha-rhythm generator (19) or a malfunction of the magnocellular and parvocellular system (20). However, alpha rhythm is produced on passive eye closure.

We have studied video-EEGs in a population of 50 children with ELMA and have observed two patterns of eye closure:

The normal quick blink pattern: The normal quick blink pattern, a positive wave is recorded in the frontal areas. The downward portion (eye closing) and the upward portion (eye opening) deflection of the positive wave lasts about 100 msec each. The eye closure phase is very brief—there is no plateau and no clinical and EEG phenomena.
The abnormal eye closure pattern: In the abnormal eye closure pattern, the eyes close slowly either spontaneously or on-command. Three main patterns are observed (a) Eyes close freely with no initial contraction and a slight flicker or flutter of the eyelids is observed at closure, which is associated with generalized alpha-theta rhythm with or without spikes in the EEG. The palpebral fissure is slightly opened. Occasionally, the upper lid will fling open and jerk, associated with slight upward deviation of gaze and brief generalized irregular spike-wave discharge. (b) The command to close the eyes is associated with an initial mild eyelid contraction of 30- to 70-msec duration before the eyelids begin to close. The closing phase—downward deflection of the positive wave—lasts 100 to 200 msec. At the end of the eye closure phase, an eyelid contraction is observed, which lasts 100 to 350 msec (plateau) before the eyes attempt to open. At the end of eye closure and during the upward deflection of the positive wave, which lasts from 150 to 500 msec, the eyelids flicker, flutter, or jerk in association either with a generalized alpha-beta rhythm of 10 to 30 mv or higher-amplitude irregular spike-wave discharges, respectively. The central posterior spread of the discharge occurs with a delay of less than 100 msec. The stronger the contraction at eye closure, the stronger the jerking during the process of eye opening and the more precise the generalized and irregular spike-and-wave discharges (GSWDs), The longer the GSWDs, the more likely the process to be repeated, as the child tries to follow the command “close your eyes” and more clear brief absences are observed. After a few repeats of the clinical and EEG phenomena, the eyes remain open. The child no longer attempts to follow the command to close the eyes. (c) The command to close the eyes is characterized by repeated eyelid contractions, associated with GSWDs, which prevent the eyes from closing. Eyes close 500 to 700 msec after the command or the initiation of the discharge and then open quickly and stare. The closing of the eyelids is associated with the slow wave and the opening with the spike of the spike-wave complex.

Clinical and Electroencephalogram Manifestations

“…There is marked jerking of the eyelids associated with 3c/s SWDs o PSWDs often irregular, immediately after eye closure and invariably positive response on IPS. The mean age of onset is 6 years and female predominate….”

–Jeavons PM. DMCN 1977

Eyelid myoclonia and absences or Jeavons syndrome with or without GTCS or other myoclonic jerks is associated with characteristic EEG features during eye closure, sleep, drowsiness, hyperventilation, and IPS and constitutes a separate syndrome.

Seizures Types

Three types of seizures characterize Jeavons syndrome: myoclonic, absences, and generalized tonic–clonic seizures. Occasionally, a tonic spasm of the eyelids is observed as a component of the marked jerking.

Myoclonic seizures are of two types: eyelid myoclonia and myoclonic jerks other than eyelid.

Myoclonic Seizures

Eyelid Myoclonia

Eyelid myoclonia of variable intensity is, by definition, always present. The eyelids may tremble, flicker, flutter or fling open and jerk with a concomitant upward deviation of the eyes and a brief absence. In bright sunlight jerking of the eyelids may be very pronounced and some of the children regarded as having self-induced epilepsy appear to have ELMA (5,6). In certain cases of typical forms of ELMA, a brief tonic spasm is observed, either in the preseptal palpebral portion of the obicularis oculi muscle, which prevents the closing movement for a few milliseconds, or in the pretarsal portion at eye closure, just before the eyelids open and jerk. Eyelid myoclonia occur, as a rule, immediately after eye closure, simultaneously with the EEG discharges. The movements are rhythmic, repetitive, slight or marked, single or multiple, even in the same patient. The tremorlike or flutter-like movements are associated in the EEG with beta-alpha rhythm occasionally intermixed with brief spike-wave discharge, when a stronger jerk interferes with the mild movements. These phenomena can be easily interrupted by eye opening. The marked jerking of the eyelids may be a single event lasting from 0.5 to 3 s or may be repeated a few times before the child succeeds to keep the eyes open and relax, sometimes with a sigh of relief. Each clinical event is associated in the EEG with generalized 3- to 5-Hz spike-wave or polyspike-wave discharge of the same duration. The repetition gives the discharges a discontinuous or fragmented pattern. Each jerk is related to the spike and the eye closing with the slow wave of the spike-and-wave complex.

The eyelid myoclonias are very frequent and easily diagnosed, but often misinterpreted for tics.

Myoclonic Jerks Other Than Eyelid

Myoclonic jerks other than eyelid myoclonia are rarely reported by the children or observed by the parents. In adults with ELMA, infrequent myoclonic jerks of the upper limbs occurred in 54.5% of the patients either independently or together with the eyelid myoclonia (12). In our population of 50 children with ELMA (mean age 7 ± 2.7 y), myoclonic jerks occurred in 34% of the cases and were mainly observed on eye closure. Myoclonic jerks and absences, if present, are usually evoked during IPS, simultaneously with eyelid myoclonia and the irregular generalized spike-wave discharge induced by eye closure. The head may jerk to one side or be drawn to one side like a magnet. Other head movements like nodding, shaking or backward jerks are also observed. The myoclonic jerk may be preceded or followed by eye opening and staring. It may be followed by a massive jerk associated with a second GSWD, if the IPS is not switched off. The intensity of head jerk varies from a subjective feeling to very strong movement. The jerks may also occur in either the arm or shoulder, but rarely occur in the lower extremities.

Only gold members can continue reading. Log In or Register to continue