Eyelid myoclonia with absences: Routine EEG is sufficient to make a diagnosis

Are the seizures under control or unnoticed? Electroclinical evaluation of epilepsy with eyelid myoclonia

PURPOSE

In this study, patients with epilepsy with eyelid myoclonia (E-EM) were evaluated according to their EEG findings, seizure outcomes, and their consistency with the final ictal EEG findings. We also investigated the possible prognostic factors.

METHODS

Patients with E-EM and at least two years of follow-up in our clinic were included in the study. We analyzed the presence of eyelid myoclonia, absence and myoclonic seizures, and generalized tonic-clonic seizures for the prior two years and then verified with the latest ictal EEG features. Video-EEGs were analyzed according to the background activity, the existence of generalized spike-wave discharge or polyspike-wave complexes, focal spike-wave discharge, photoparoxysmal responses, and fast activity.

RESULTS

21 patients were involved in this study. In six patients, the seizures were undetected on the first EEGs, whereas they were detected on subsequent ones. The seizures were captured on the first EEGs of six patients; however, they disappeared on subsequent ones. Only one patient had seizures detected on every EEG. The consistency of the seizures was variable in eight patients. At the final follow-up, seizures were reported as being under control for more than two years in 12 patients, according to patients and their parents' reports. However, ictal EEG findings were detected in six of these patients. No electroclinical feature was associated with seizure freedom.

CONCLUSION

This study provides further evidence that seizure freedom in E-EM patients is overestimated. The patients and their parents may not be aware of the seizures. Therefore, video-EEG monitorization is essential during follow-up.

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%.

The seizures that wake up with the patient: The effect of sleep deprivation and short sleep on epilepsy with eyelid myoclonia

OBJECTIVE

In this study, our aim was to demonstrate the effect of sleep deprivation, short sleep, and awakening on photoparoxysmal responses (PPR) and eyelid myoclonia (EM) in patients with Epilepsy with Eyelid Myoclonia (E-EM).

METHODS

E-EM patients with at least 1 year of follow-up in our clinic were included in the study. Video EEG(v-EEG) analyses were divided into three periods of wakefulness, sleep, and awakening. The PPR and onset of EMs were investigated.

RESULTS

32 patients met the study criteria, of which 56.3% (n = 18) were male. The mean age at disease onset was 7.7 ± 4.1 years. The mean age at EEG recording was 12.4 ± 4.0 years. EM was observed only on awakening in 78.1% of patients (n = 22), of which it was seen only during intermittent photic stimulation (IPS) in 43.7% (n = 14). Eye closure (EC) sensitivity was detected in all patients. The proportion of patients with a PPR was significantly higher on awakening than before sleep (p = 0.01).

CONCLUSIONS

This study showed that EM is most prominent and sometimes can only be detected in the awakening period in E-EM. In order to detect E-EM, v-EEG recordings including both pre-sleep and post-sleep wakefulness periods should be recorded, with intermittent photic stimulation performed in both periods.

Electroclinical Features and Long-term Seizure Outcome in Patients With Eyelid Myoclonia With Absences

BACKGROUND AND OBJECTIVES

Eyelid myoclonia with absences (EMA) is a generalized epilepsy syndrome whose prognosis and clinical characteristics are still partially undefined. We investigated electroclinical endophenotypes and long-term seizure outcome in a large cohort of EMA patients.

METHODS

In this multicenter retrospective study, EMA patients with ≥5 years of follow-up were included. We investigated prognostic patterns and sustained terminal remission (STR), along with their prognostic factors. Moreover, a two-step cluster analysis was used to investigate the presence of distinct EMA endophenotypes.

RESULTS

We included 172 patients, with a median age at onset of 7 years (interquartile range (IQR) 5-10) and a median follow-up duration of 14 years (IQR 8.25-23.75). Sixty-six patients (38.4%) displayed a non-remission pattern, whereas remission and relapse patterns were encountered in 56 (32.6%) and 50 (29.1%) subjects. Early epilepsy onset, history of febrile seizures (FS) and eyelid myoclonia (EM) status epilepticus significantly predicted a non-remission pattern according to multinomial logistic regression analysis. STR was achieved by 68 (39.5%) patients with a mean latency of 14.05 years (SD ± 12.47). Early epilepsy onset, psychiatric comorbidities, and a history of FS and generalized tonic-clonic seizures (GTCS) were associated with a lower probability of achieving STR according to a Cox regression proportional hazards model. Antiseizure medication (ASM) withdrawal was attempted in 62/172 patients, and seizures relapsed in 74.2%. Cluster analysis revealed two distinct clusters with 86 patients each. Cluster 2, which we defined as "EMA-plus", was characterized by an earlier age at epilepsy onset, higher rate of intellectual disability, EM status epilepticus, generalized paroxysmal fast activity, self-induced seizures, FS, and poor ASM response, whereas Cluster 1, the "EMA-only" cluster, was characterized by a higher rate of seizure remission and more favorable neuropsychiatric outcome.

DISCUSSION

Early epilepsy onset was the most relevant prognostic factor for poor treatment response. A long latency between epilepsy onset and ASM response was observed, suggesting the impact of age-related brain changes in EMA remission. Finally, our cluster analysis showed a clear-cut distinction of EMA patients into an EMA-plus insidious subphenotype and an EMA-only benign cluster that strongly differed in terms of remission rates and cognitive outcomes.

Monitoring the frequency and duration of epileptic seizures: "A journey through time"

Seizure monitoring plays an undeniably important role in diagnosing and managing epileptic seizures. Establishing the frequency and duration of seizures is crucial for assessing the burden of this chronic neurological disease, selecting treatment methods, determining how frequently these methods are applied, and informing short and long-term therapeutic decisions. Over the years, seizure monitoring tools and methods have evolved and become increasingly sophisticated; from home seizure diaries to EEG monitoring to cutting-edge responsive neurostimulation systems. In this article, the various methods of seizure monitoring are reviewed.

The Human Default Consciousness and Its Disruption: Insights From an EEG Study of Buddhist Jhāna Meditation

The “neural correlates of consciousness” (NCC) is a familiar topic in neuroscience, overlapping with research on the brain’s “default mode network.” Task-based studies of NCC by their nature recruit one part of the cortical network to study another, and are therefore both limited and compromised in what they can reveal about consciousness itself. The form of consciousness explored in such research, we term the human default consciousness (DCs), our everyday waking consciousness. In contrast, studies of anesthesia, coma, deep sleep, or some extreme pathological states such as epilepsy, reveal very different cortical activity; all of which states are essentially involuntary, and generally regarded as “unconscious.” An exception to involuntary disruption of consciousness is Buddhist jhāna meditation, whose implicit aim is to intentionally withdraw from the default consciousness, to an inward-directed state of stillness referred to as jhāna consciousness, as a basis to develop insight. The default consciousness is sensorily-based, where information about, and our experience of, the outer world is evaluated against personal and organic needs and forms the basis of our ongoing self-experience. This view conforms both to Buddhist models, and to the emerging work on active inference and minimization of free energy in determining the network balance of the human default consciousness. This paper is a preliminary report on the first detailed EEG study of jhāna meditation, with findings radically different to studies of more familiar, less focused forms of meditation. While remaining highly alert and “present” in their subjective experience, a high proportion of subjects display “spindle” activity in their EEG, superficially similar to sleep spindles of stage 2 nREM sleep, while more-experienced subjects display high voltage slow-waves reminiscent, but significantly different, to the slow waves of deeper stage 4 nREM sleep, or even high-voltage delta coma. Some others show brief posterior spike-wave bursts, again similar, but with significant differences, to absence epilepsy. Some subjects also develop the ability to consciously evoke clonic seizure-like activity at will, under full control. We suggest that the remarkable nature of these observations reflects a profound disruption of the human DCs when the personal element is progressively withdrawn.

Jeavons Syndrome: Clinical Features and Response to Treatment

BACKGROUND

Jeavons syndrome is an underreported epileptic syndrome characterized by eyelid myoclonia, eyelid closure-induced seizures or electroencephalography paroxysms, and photosensitivity. Drug-resistant epilepsy is common, but the prognostic factors and clinical course leading to drug resistance have not been well characterized.

METHODS

We identified 30 patients who met the diagnostic criteria of Jeavons syndrome at a single institution between January 1, 2000 and December 15, 2016. Criteria for Jeavons syndrome included all of the following: (1) eyelid myoclonia with or without absences, (2) eye-closure-induced seizures or electroencephalography paroxysms, and (3) seizure onset after 12 months of age. We reviewed and described the epilepsy history, antiepileptic drug trials, and response to treatments.

RESULTS

Mean age at seizure onset was 7.3 years, and 80% were female. Absence seizures (63%) and generalized tonic-clonic seizures (23%) were most common at onset. Diagnosis was delayed by an average of 9.6 years. After a median follow-up of two years, 80% of patients had drug resistant epilepsy and 70% experienced generalized tonic-clonic seizures. Generalized tonic-clonic seizures and seizure types other than absence seizures increased the risk of drug-resistant epilepsy (P values 0.049 and 0.03, respectively). Valproic acid, lamotrigine, ethosuximide, and levetiracetam were the most effective in reducing seizures by more than 50%.

CONCLUSIONS

The diagnosis of Jeavons syndrome is often delayed. Generalized tonic-clonic seizures and seizure types other than absence seizures may be predictors of drug-resistant epilepsy among patients with Jeavons syndrome.

Does Epileptiform Activity Represent a Failure of Neuromodulation to Control Central Pattern Generator-Like Neocortical Behavior?

Rhythmic motor patterns in invertebrates are often driven by specialized “central pattern generators” (CPGs), containing small numbers of neurons, which are likely to be “identifiable” in one individual compared with another. The dynamics of any particular CPG lies under the control of modulatory substances, amines, or peptides, entering the CPG from outside it, or released by internal constituent neurons; consequently, a particular CPG can generate a given rhythm at different frequencies and amplitudes, and perhaps even generate a repertoire of distinctive patterns. The mechanisms exploited by neuromodulators in this respect are manifold: Intrinsic conductances (e.g., calcium, potassium channels), conductance state of postsynaptic receptors, degree of plasticity, and magnitude and kinetics of transmitter release can all be affected. The CPG concept has been generalized to vertebrate motor pattern generating circuits (e.g., for locomotion), which may contain large numbers of neurons – a construct that is sensible, if there is enough redundancy: that is, the large number of neurons consists of only a small number of classes, and the cells within any one class act stereotypically. Here we suggest that CPG and modulator ideas may also help to understand cortical oscillations, normal ones, and particularly transition to epileptiform pathology. Furthermore, in the case illustrated, the mechanism of the transition appears to be an exaggerated form of a normal modulatory action used to influence sensory processing.

Preliminary neurocognitive outcomes in Jeavons syndrome

Jeavons syndrome (JS, eyelid myoclonia with absences [EMA]) consists of a triad of symptoms including eyelid myoclonia that may be accompanied by absence seizures, eye closure-induced EEG paroxysms or seizures, and photosensitivity. The age of onset ranges between 2 and 14 years with symptoms peaking between 6 and 8 years of age. Though investigation of the clinical, EEG, and neurological features of JS has occurred, neurocognitive functioning has not been well-delineated despite suggestion that a subtype of the syndrome is characterized in part by cognitive impairment. The purpose of this study was to define neurocognitive functioning in a more detailed manner by examining global IQ and relevant neurocognitive domains (i.e., verbal and nonverbal reasoning, attention, executive functioning, memory) in pediatric patients. The sample (N=6, 4 females) ranged in age from 8 to 15 years (M=11, SD=2.82). All participants completed neuropsychological evaluations. Statistical analyses revealed performance that was below average on measures of global IQ, processing speed and rote, verbal learning coupled with average nonverbal reasoning, and sustained attention. There was also evidence of impaired higher-level verbal reasoning. While global IQ ranged from low average to borderline impaired, no participant could be accurately described as impaired or having intellectual disability (ID) given the consistently average performance noted on some higher-order tasks including nonverbal reasoning.

Eyelid myoclonia seizures in adults: An alternate look at the syndrome paradox

OBJECTIVES

Eyelid myoclonia (EM), without or with absences (EMA), is induced by eye closure (ECL)-associated generalized paroxysms of polyspikes and waves. Although considered as an epileptic syndrome, it has been listed as a type of seizure in the recent epilepsy classifications, perhaps because of its clinical heterogeneity. In this study, we aimed to specifically study the clinical and electroencephalogram (EEG) features and the prognosis of long-term followed-up adult patients with EMs and to determine common points between EMAs, idiopathic generalized epilepsies (IGEs), and symptomatic epilepsies.

METHODS

Between 1996 and November 2011, 61 adult patients with EMs with or without absences and bilateral EEG paroxysms were retrospectively enrolled in the study and followed up for 1-34 years (mean: 5.8 years).

RESULTS

According to patient history, seizure semiology, and EEG findings, we classified the patients having EM seizures into three main groups. In group 1 (n=31), all patients had prominent EMs with or without absences associated with upward rolling of eyeballs. The second group included 20 patients with EM seizures associated with generalized tonic-clonic seizures (GTCSs) and/or massive myoclonias. The third group of 7 patients had varying diagnosis of symptomatic epilepsies. In the first group with pure EMA, the diagnosis was more delayed than in the other groups (p=0.01). In the group with pure EMA, EMs continued in adulthood (p=0.00), and only 24% of patients were seizure-free, which was considered poor prognosis. On EEG, occipital (n=3) and frontal (n=4) focal discharges were found in the group with pure EMA. Interestingly, 2 patients with symptomatic epilepsy with frontal lesions also had EM seizures.

CONCLUSION

The patients with pure EMA have many similarities to patients with IGEs. We also demonstrated that EMs could be seen as a seizure type in symptomatic epilepsies. Eyelid myoclonia with absences meets the criteria for an epileptic syndrome with the early onset and long duration of seizures, special seizure type, specific EEG findings, possibility of cognitive impairment, precipitating modalities, photosensitivity, and presence of family history, suggesting a strong genetic background.

Absence seizures: a review of recent reports with new concepts

Absence seizures with bilateral spike-wave (SW) complexes at 3Hz are divided into the childhood form, with onset at around 6 years of age, and the juvenile form, with onset usually at 12 years of age. These seizures typically last 9-12s and, at times, are activated by hyperventilation and occasionally by photic stimulation. Generalized tonic-clonic (GTC) seizures may also occur, especially in the juvenile form. There may be cognitive changes, in addition to linguistic and behavioral problems. Possible mechanisms for epileptogenesis may involve GABAergic systems, but especially T-calcium channels. The thalamus, especially the reticular nucleus, plays a major role, as does the frontal cortex, mainly the dorsolateral and orbital frontal areas, to the extent that some investigators have concluded that absence seizures are not truly generalized, but rather have selective cortical networks, mainly ventromesial frontal areas and the somatosensory cortex. The latter network is a departure from the more popular concept of a generalized epilepsy. Between the "centrencephalic" and "corticoreticular" theories, a "unified" theory is presented. Proposed genes include T-calcium channel gene CACNA1H, likely a susceptible gene in the Chinese Han population and a contributory gene in Caucasians. Electroencephalography has revealed an interictal increase in prefrontal activity, essential for the buildup of the ictal SW complexes maximal in that region. Infraslow activity can also be seen during ictal SW complexes. For treatment, counter to common belief, ethosuximide may not increase GTC seizures, as it reduces low-threshold T-calcium currents in thalamic neurons. Valproic acid and lamotrigine are also first-line medications. In addition, zonisamide and levetiracetam can be very helpful in absence epilepsy.