Focal clinical and electroencephalographic features in patients with juvenile myoclonic epilepsy

Idiopathic generalized epilepsies in the epilepsy monitoring unit: Systematic quantification of focal EEG and semiological signs

OBJECTIVE

Focal seizure symptoms (FSS) and focal interictal epileptiform discharges (IEDs) are common in patients with idiopathic generalized epilepsies (IGEs), but dedicated studies systematically quantifying them both are lacking. We used automatic IED detection and localization algorithms and correlated these EEG findings with clinical FSS for the first time in IGE patients.

METHODS

32 patients with IGEs undergoing long-term video EEG monitoring were systematically analyzed regarding focal vs. generalized IEDs using automatic IED detection and localization algorithms. Quantitative EEG findings were correlated with FSS.

RESULTS

We observed FSS in 75% of patients, without significant differences between IGE subgroups. Mostly varying/shifting lateralizations of FSS across successive recorded seizures were seen. We detected a total of 81,949 IEDs, whereof 19,513 IEDs were focal (23.8%). Focal IEDs occurred in all patients (median 13% focal IEDs per patient, range 1.1 - 51.1%). Focal IED lateralization and localization predominance had no significant effect on FSS.

CONCLUSIONS

All included patients with IGE showed focal IEDs and three-quarter had focal seizure symptoms irrespective of the specific IGE subgroup. Focal IED localization had no significant effect on lateralization and localization of FSS.

SIGNIFICANCE

Our findings may facilitate diagnostic and treatment decisions in patients with suspected IGE and focal signs.

Focal electroclinical features in generalized tonic-clonic seizures: Decision flowchart for a diagnostic challenge

OBJECTIVE

Bilateral tonic-clonic seizures with focal semiology or focal interictal electroencephalography (EEG) can occur in both focal and generalized epilepsy types, leading to diagnostic errors and inappropriate therapy. We investigated the prevalence and prognostic values of focal features in patients with idiopathic generalized epilepsy (IGE), and we propose a decision flowchart to distinguish between focal and generalized epilepsy in patients with bilateral tonic-clonic seizures and focal EEG or semiology.

METHODS

We retrospectively analyzed video-EEG recordings of 101 bilateral tonic-clonic seizures from 60 patients (18 with IGE, 42 with focal epilepsy). Diagnosis and therapeutic response were extracted after ≥1-year follow-up. The decision flowchart was based on previous observations and assessed concordance between interictal and ictal EEG.

RESULTS

Focal semiology in IGE was observed in 75% of seizures and 77.8% of patients, most often corresponding to forced head version (66.7%). In patients with multiple seizures, direction of head version was consistent across seizures. Focal interictal epileptiform discharges (IEDs) were observed in 61.1% of patients with IGE, whereas focal ictal EEG onset only occurred in 13% of seizures and 16.7% of patients. However, later during the seizures, a reproducible pattern of 7-Hz lateralized ictal rhythm was observed in 56% of seizures, associated with contralateral head version. We did not find correlation between presence of focal features and therapeutic response in IGE patients. Our decision flowchart distinguished between focal and generalized epilepsy in patients with bilateral tonic-clonic seizures and focal features with an accuracy of 96.6%.

SIGNIFICANCE

Focal semiology associated with bilateral tonic-clonic seizures and focal IEDs are common features in patients with IGE, but focal ictal EEG onset is rare. None of these focal findings appears to influence therapeutic response. By assessing the concordance between interictal and ictal EEG findings, one can accurately distinguish between focal and generalized epilepsies.

Isolated Unilateral EEG Findings in Juvenile Myoclonic Epilepsy: A Case Report

Juvenile myoclonic epilepsy (JME) has well-defined clinical and electrophysiological features. On the other hand, large case series have shown that focal and asymmetrical discharges may accompany generalized epileptiform activities in JME. Although it is known that these non-generalized electrophysiological findings do not exclude the diagnosis of this syndrome, some findings may create confusion in the differential diagnosis. In this case report, a case of JME with electroencephalographic findings characterized by isolated unilateral epileptiform activities without typical generalized discharges was discussed. The current case clinically presented with involuntary jerk movements in the bilateral upper extremities. It has been determined that these movements are uni/bilateral myoclonic beats based on home video recordings. Metabolic, toxic and structural problems were excluded in the investigations for the etiology of myoclonus. In the electrophysiological examination performed for epileptic processes, epileptiform discharges localized to the isolated right hemisphere were observed. JME was considered primarily due to clinical findings in the patient, and effective seizure control was achieved in a 4-year follow-up under anti-seizure treatment. The peculiarity of the case is the presence of electrophysiology recordings of isolated unilateral epileptiform activity during the 4-year follow-up period. It should be emphasized that there is no case of JME diagnosed with isolated unilateral epileptiform activity in the absence of generalized spike-slow waves or multiple spike-slow waves in the literature.

EEG Markers of Treatment Resistance in Idiopathic Generalized Epilepsy: From Standard EEG Findings to Advanced Signal Analysis

Idiopathic generalized epilepsy (IGE) represents a common form of epilepsy in both adult and pediatric epilepsy units. Although IGE has been long considered a relatively benign epilepsy syndrome, a remarkable proportion of patients could be refractory to treatment. While some clinical prognostic factors have been largely validated among IGE patients, the impact of routine electroencephalography (EEG) findings in predicting drug resistance is still controversial and a growing number of authors highlighted the potential importance of capturing the sleep state in this setting. In addition, the development of advanced computational techniques to analyze EEG data has opened new opportunities in the identification of reliable and reproducible biomarkers of drug resistance in IGE patients. In this manuscript, we summarize the EEG findings associated with treatment resistance in IGE by reviewing the results of studies considering standard EEGs, 24-h EEG recordings, and resting-state protocols. We discuss the role of 24-h EEG recordings in assessing seizure recurrence in light of the potential prognostic relevance of generalized fast discharges occurring during sleep. In addition, we highlight new and promising biomarkers as identified by advanced EEG analysis, including hypothesis-driven functional connectivity measures of background activity and data-driven quantitative findings revealed by machine learning approaches. Finally, we thoroughly discuss the methodological limitations observed in existing studies and briefly outline future directions to identify reliable and replicable EEG biomarkers in IGE patients.

Analysis of Clinical Characteristics, Background, and Paroxysmal Activity in EEG of Patients with Juvenile Myoclonic Epilepsy

Juvenile myoclonic epilepsy (JME) appears in adolescence with myoclonic, absence, and generalized tonic clonic (GTC) seizures with paroxysmal activity of polyspike and slow wave (PSW), or spike and wave (SW) complexes in EEG. Our aim was to analyze the clinical characteristics, background EEG activity, and paroxysmal events in 41 patients with JME. Background EEG activity was analyzed with visual, quantitative (QEEG), and neurometric parameters. Our JME patients started with absence seizures at 11.4 ± 1.5 years old, myoclonic seizures at 13.6 ± 2.5 years, and GTC seizures at 15.1 ± 0.8 years. The seizures presented in awakening at 7:39 h with sleep deprivation, alcoholic beverage intake, and stress as the most frequent precipitant factors. Paroxysmal activity was of PSW and fast SW complexes with 40.5 ± 62.6 events/hour and a duration of 1.7 s. Right asymmetric paroxysmal activity was present in 68.3% of patients. Background EEG activity was abnormal in 31.7% of patients with visual analysis. With QEEG beta AP (absolute power) increase and AP delta decrease were the most frequent abnormalities found. Spectral analysis showed that 48.7% of patients had normal results, and 26.83% and 24.4% had higher and lower frequencies than 10.156 Hz, respectively. We concluded that, with visual analysis, background EEG activity was abnormal in a few patients and the abnormalities increased when QEEG was used.

Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: A European Academy of Neurology, European Sleep Research Society and International League against Epilepsy-Europe consensus review

BACKGROUND

Some epilepsy syndromes (sleep-related epilepsies [SRE]) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life.

PURPOSES

To define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2).

METHODS

The project was conducted under the auspices of the European Academy of Neurology (EAN), the European Sleep Research Society (ESRS) and the International League against Epilepsy (ILAE) Europe. The framework of the document entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For literature search a step-wise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library.

RESULTS

Scenario 1: despite a low quality of evidence, recommendations on anamnestic evaluation, tools for capturing the event at home or in the laboratory are provided for specific SRE. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizures control.

CONCLUSIONS

Definitive procedures for evaluating patients with SRE are lacking. We provide advice that could be of help for standardising and improving the diagnostic approach of specific SRE. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: an EAN, ESRS and ILAE-Europe consensus review

BACKGROUND AND PURPOSE

Some epilepsy syndromes (sleep-related epilepsies, SREs) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life. Our purpose was to define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2).

METHODS

The project was conducted under the auspices of the European Academy of Neurology, the European Sleep Research Society and the International League Against Epilepsy Europe. The framework entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For the literature search a stepwise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library.

RESULTS

Scenario 1: Despite a low quality of evidence, recommendations on anamnestic evaluation and tools for capturing the event at home or in the laboratory are provided for specific SREs. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizure control.

CONCLUSIONS

Definitive procedures for evaluating patients with SRE are lacking. Advice is provided that could be of help for standardizing and improving the diagnostic approach of specific SREs. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Juvenile myoclonic epilepsy mimic associated with CHD2 gene mutation

This paper reports the electroclinical manifestations of an epilepsy syndrome associated with a chromodomain helicase DNA-binding protein 2 (CHD2) gene mutation with clinical semiology and electroencephalographic (EEG) features consistent with juvenile myoclonic epilepsy (JME). Myoclonic and myoclonic-tonic–clonic seizures, as well as generalized 4- to 5-Hz high-amplitude spike–wave and polyspike–wave discharges, were well characterized in an adolescent. However, the atypical age of onset, developmental disability, and apparent drug resistance led to suspicion of an alternative etiology for epilepsy, subsequently verified as a CHD2 gene mutation. When atypical features are present, a JME mimic should be suspected in the differential diagnosis of the more established syndrome of JME.

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Chromodomain helicase DNA-binding protein 2 (CHD2) mutation is associated with epilepsy.

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A juvenile myoclonic epilepsy phenotype with atypical history may be a mimic.

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Cases concerning for juvenile myoclonic epilepsy mimics should be considered for genetic testing.

Unmasking of myoclonus by lacosamide in generalized epilepsy

Lacosamide is a new-generation antiseizure medication that is approved for use as an adjunctive treatment and monotherapy in focal epilepsy. Its use in generalized epilepsy, however, has not been adequately evaluated in controlled trials. We report a 67-year-old woman who experienced new-onset myoclonic seizures after initiation of lacosamide. We presume that she had an undiagnosed generalized epilepsy syndrome, likely juvenile myoclonic epilepsy. Myoclonic seizures were not reported before introducing lacosamide and completely resolved after lacosamide was discontinued. This suggests that lacosamide may have the potential to worsen myoclonus, similar to what has been reported with another sodium channel agent, lamotrigine, in some individuals with genetic generalized epilepsy (GGE).

Juvenile Myoclonic Epilepsy in Rural Western India: Not Yet a Benign Syndrome

Purpose. To study prevalence of uncontrolled seizures in patients with juvenile myoclonic epilepsy [JME] and assess factors responsible for it. Methods. An ambispective study of all patients with JME attending our epilepsy clinic was done. We recruited all patients with JME evaluated between 1 January 2009 and 31 December 2013 and followed them up to 31 December 2015. Results. Amongst 876 patients with epilepsy, JME was present in 73 patients. Amongst them, 53 [72.6%] had uncontrolled seizures prior to neurology consultation. Factors responsible for uncontrolled seizures included pitfalls in diagnosis like absence of prior neurology consultation missed history of myoclonus in prior consults and pitfalls in interpretation of EEG. Pitfalls in management were incorrect antiepileptic drug use, underdosing of AED, noncompliance with lifestyle, noncompliance with medicines, associated psychogenic nonepileptiform events, patients deliberately missing medicines for secondary gain, and concomitant alternative medicine use. 45 (84.9%) patients had "pseudorefractoriness." True refractoriness [seizures despite 2 correctly dosed rational drugs] was seen in 8 (15.1%) patients only. Conclusion. Three-fourth of our patients had uncontrolled seizures initially, predominantly due to pitfalls in its diagnosis and management. Improving patient awareness and primary physician training for JME management is the need of the hour.

Focal interictal epileptiform discharges in idiopathic generalized epilepsy

Are idiopathic generalized epilepsies (IGEs) truly generalized? Do IGEs represent a continuum or rather distinct syndromes? Focal changes in the electroencephalography (EEG) have been reported in IGEs. The aim of this work is to investigate focal interictal epileptiform discharges (IEDs) in IGEs, and their relation to clinical variables. Forty-one IGE patients (classified according to ILAE, 2001) were recruited from a tertiary center (age 23 ± 10.938 years). Their files were reviewed and they were subjected to clinical examination and interictal EEG. Patients with focal IEDs were compared to those without focal IEDs. Nine patients had juvenile myoclonic epilepsy (JME) and 32 had idiopathic epilepsy with generalized tonic-clonic seizures only (EGTCSA). Focal IEDs were found in 20 patients, mostly in the frontal (45.5 %) and temporal (31.8 %) distribution. Patients with focal IEDs were treated with a larger number of combined antiepileptic drugs (AEDs) (p value = 0.022). No significant difference was found between the two groups regarding age, sex, age at onset, epilepsy syndrome, seizure frequency, family history, AEDs used (sodium valproate and carbamazepine) and their doses. Seventeen EGTCSA patients had focal IEDs. They were treated with larger number of combined AEDs (p value = 0.0142). No significant difference was found between the EGTCSA patients with and those without focal IEDs regarding age, sex, age at onset, seizure frequency, family history and AEDs doses. Caution must be applied in the interpretation of interictal focal IEDs. These focal changes may be related to prognosis, however this needs further investigation.

Auras in generalized epilepsy

OBJECTIVE

We studied the frequency of auras in generalized epilepsy (GE) using a detailed semistructured diagnostic interview.

METHODS

In this cross-sectional study, participants with GE were drawn from the Epilepsy Phenome/Genome Project (EPGP). Responses to the standardized diagnostic interview regarding tonic-clonic (grand mal) seizures were then examined. This questionnaire initially required participants to provide their own description of any subjective phenomena before their "grand mal seizures." Participants who provided answers to these questions were considered to have an aura. All participants were then systematically queried regarding a list of specific symptoms occurring before grand mal seizures, using structured (closed-ended) questions.

RESULTS

Seven hundred ninety-eight participants with GE were identified, of whom 530 reported grand mal seizures. Of these, 112 (21.3%) reported auras in response to the open-ended question. Analysis of responses to the closed-ended questions suggested that 341 participants (64.3%) experienced at least one form of aura.

CONCLUSIONS

Auras typically associated with focal epilepsy were reported by a substantial proportion of EPGP subjects with GE. This finding may support existing theories of cortical and subcortical generators of GE with variable spread patterns. Differences between responses to the open-ended question and closed-ended questions may also reflect clinically relevant variation in patient responses to history-taking and surveys. Open-ended questions may underestimate the prevalence of specific types of auras and may be in part responsible for the underrecognition of auras in GE. In addition, structured questions may influence participants, possibly leading to a greater representation of symptoms.