Nonconvulsive status epilepticus in eyelid myoclonia with absences--evidence of provocation unrelated to photosensitivity

A comprehensive narrative review of epilepsy with eyelid myoclonia

Epilepsy with eyelid myoclonia (EEM) is a generalized epilepsy syndrome with childhood-onset and 2:1 female predominance that consists of: 1. eyelid myoclonia with or without absence seizures, 2. eye closure induced seizures or EEG paroxysms, 3. clinical or EEG photosensitivity. While eyelid myoclonia is the disease hallmark, other seizure types, including absence seizures and generalized tonic-clonic seizures, may be present. It is thought to have a genetic etiology, and around one-third of patients may have a positive family history of epilepsy. Recently, specific genetic mutations have been recognized in a minority patients, including in SYNGAP1, NEXMIF, RORB, and CHD2 genes. There are no randomized controlled trials in EEM, and the management literature is largely restricted to small retrospective studies. Broad-spectrum antiseizure medications such as valproate, levetiracetam, lamotrigine, and benzodiazepines are typically used. Seizures typically persist into adulthood, and drug-resistant epilepsy is reported in over 50%.

Case Report: A Case of Eyelid Myoclonic Status With Tonic-Clonic Seizure and Literature Review

Eyelid myoclonus with or without absence epilepsy is a rare and usually misdiagnosed disease in the neurology department. It is an idiopathic general epileptic syndrome, the onset period is 6-8 years, and is more common in girls. It is characterized by rapid abnormal eye blinking, accompanied by upward rolling of the eye and slight backward movement of the head, with eye closure sensitivity and photosensitivity. The seizure is frequent and short, dozens or even hundreds of times a day; a small number of patients may have eyelid myoclonus status. We report a patient who visits the hospital for the first time with eyelid myoclonic problem; the patient continued to wink the eyes, eye rolled up, and backward movement of the head, accompanied by impairment of consciousness. Video electroencephalography (VEEG) suggests continued spike slow-wave, polyspike slow-wave. After the patient had 2, 4, 6, 8, 10, 12, and 14 Hz of intermittent photic stimulation (IPS), her seizures and epileptic discharges reduced or stopped. Seven min after giving stimulation at 20 Hz, the child developed an occipital-initiated tonic-clonic seizure, which demonstrated that after sufficient IPS stimulation, the occiput cortex became excited and initiated a brain network, leading to diffuse brain discharge and tonic-clonic seizures. At 1 h after onset, the child developed a nonconvulsive state, with impairment of consciousness despite no eyelid myoclonic movements, and VEEG suggested a large number of epileptic discharges. After 10 min of administrating midazolam, the patient's EEG immediately became normal, and the patient regained consciousness. Therefore, this paper presents an eyelid myoclonus status patient with occipital origin seizure, we recorded the whole course of the disease and the treatment effect, and reviewed the literature accordingly.

Overlap cases of eyelid myoclonia with absences and juvenile myoclonic epilepsy

Eyelid myoclonia with absences (EMA) and juvenile myoclonic epilepsy (JME) are two separate epileptic syndromes included in the new classification of epilepsies and epileptic syndromes by ILAE in 2001. Both are idiopathic generalized epilepsies with their clinical onset in the first two decades. EMA is characterized by eyelid myoclonia associated with absences and photosensitivity. Self-induced seizures are frequently seen in EMA. It can be associated with mildly mental retardation and resistance to treatment. JME includes three types of generalized seizures: typical absences, myoclonic jerks and generalized tonic-clonic seizures. The myoclonic jerks occur almost exclusively on awakening, involve preferently the upper extremities, may rarely affect the lower extremities or the entire body. More severe attacks may be accompanied by a fall. The myoclonic jerks occur rarely in EMA. They are usually mild and are freqently restricted to the upper extremities. Generalized tonic-clonic seizures, photosensitivity and generalized polyspike-wave discharges provoked by eye closure are features of both epileptic syndromes. In this study, we describe four female patients with eyelid myoclonia associated with absences, myoclonic jerks causing falling down and rare generalized tonic-clonic seizures. All patients had good school performance and total seizure control under sodium valproate treatment. Their EEGs show generalized polyspike-wave discharges with a frequency of 3.5-6Hz always appearing a few seconds after eye closure and photoparoxysmal response. These patients show the characterictics of both epileptic syndromes. It is clinically important to make a syndromic diagnosis for an optimum advise on treatment, lifestyle restrictions and prognosis. In this study, we have gathered evidence that EMA and JME are dynamic syndromes that tend to evolve into one another.

Status Epilepticus in Idiopathic Generalized Epilepsy

Status epilepticus (SE) can take various forms in idiopathic generalized epilepsy (IGE), some of which forms also occur in symptomatic or focal epilepsies. Although the clinical semiology of the SE episodes may be similar in these different epilepsies, the frequency, response to treatment and prognosis differ. (a) Convulsive SE is surprisingly uncommon in IGE and much less common than in the secondarily generalized or partial epilepsies. Also, when it does occur, it usually responds rapidly to treatment. (b) Typical absence SE occurs only in patients with IGE (the subcategories with typical absence seizures) and also in the syndrome of de novo absence SE of late onset. This form of nonconvulsive SE should be differentiated from atypical absence SE, which occurs in the secondarily generalized epilepsy encephalopathies, and from complex partial SE which occurs in focal epilepsy. The clinical symptoms of these three types overlap but the prognosis and response to treatment are different. The mechanisms underlying absence SE are uncertain and may include both genetic and environmental factors. The termination of absence seizures has been hypothesized to be due to persistent activation of a depolarizing current in thalamocortical neurons that inactivates T-type calcium channels. SE could thus result from dysfunction of this channel or mechanisms that hyperpolarize thalamocortical neurons-these include decreased cortical inhibition, increased reticular thalamic neuronal activity or increased thalamocortical neuron GABA(B)-receptor activation. (c) Generalized electrographic SE is encountered in IGE in the syndrome of phantom absence with GTCS. It also occurs in ESES and in the Landau-Kleffner syndrome. The seizure phenomenology overlaps with the focal SE of temporal or frontal lobe epilepsy. (d) Myoclonic SE is also uncommon in IGE but occurs in juvenile myoclonic epilepsy. It is more commonly encountered in progressive myoclonic epilepsies, myoclonic-astatic epilepsy and in the Dravet syndrome. (e) Autonomic status occurs largely in the Panayiotopoulos syndrome. It is included here under the rubric of IGE, although the epilepsy has focal as well as generalized features and its nosological position is controversial. Fifty percent of seizures in this syndrome could be classified as status epilepticus. There is no doubt that convulsive SE can result in cerebral damage. In animal models of focal SE, nonconvulsive forms can also result in cerebral damage, but cerebral damage is not observed in animal models of absence SE. Similarly, cerebral damage seems not to occur in the forms of nonconvulsive SE in human IGE.

Recurrent absence status epilepticus: clinical and EEG characteristics

In order to outline the clinical and EEG characteristics of recurrent absence status epilepticus (ASE), eight cases with more than two attacks of ASE were studied. Their current ages were between 13 and 84 years, and five of the patients were women. There was a history of epilepsy in five of the patients before the first ASE episode. A varying degree of confusion was the main clinical symptom with associated mild motor signs like perioral, eyelid and generalised myoclonus, seen in one, two and four patients respectively. Two of the patients had juvenile myoclonic epilepsy. One patient had an atypical form of childhood absence epilepsy characterised by recurrent ASE attacks on awakening. There were two patients with phantom absences and late onset generalised convulsions, one patient with perioral myoclonia and absences, and finally two patients with eyelid myoclonia with absences, which are proposed syndromes. On the EEGs that revealed the diagnosis of ASE, there was a marked variability of the generalised multispike and wave discharges. The EEG findings appeared to be syndrome-related with some exceptions. IV Clonazepam lead to a dramatic improvement. Our study shows that the majority of recurrent ASE cases do not fit into the International syndrome classification.

Clinical heterogeneity in eyelid myoclonia, with absences, and epilepsy

Eyelid myoclonia with absences should always be considered in the investigation of children with epilepsy.

Eyelid fluttering accompanying diffuse epileptic EEG induced by eye closure

A 13-year-old male exhibited the following clinical and electroencephalographic (EEG) manifestations. He exhibited marked photosensitivity on EEG from the first visit at 9 years of age until 11 years of age and had an episode of television epilepsy at 9 years of age. Generalized epileptic EEG findings followed by marked eyelid fluttering, induced by eye closure in a bright room that lasted until the eyes were opened, but not by eye closure in a dark room, were first noticed at 11 years of age. A generalized epileptiform EEG was not induced when the light was turned off if the eyes were kept open. His photosensitivity disappeared by 12 years of age, but the eyelid fluttering with epileptic EEG induced by eye closure was still present at 13 years of age. The epileptic EEG was thought to be induced by a modification of the retinal input on eye closure, not by mechanical or sensory stimulation on eye closure or fixation-off sensitivity. In addition, in this patient a change from photosensitive to eye closure-sensitive epilepsy seemed to occur, which suggests that the correlation between the epileptic EEG and retinal input are complex.