Juvenile myoclonic epilepsy: a clinical and sleep EEG study

Sleep in juvenile myoclonic epilepsy: A systematic review

Sleep disturbances significantly impact the lives of individuals with Juvenile Myoclonic Epilepsy (JME). This study aimed to investigate sleep studies, disturbances, and the impact of anti-seizure drugs on sleep in JME patients. Relevant studies were retrieved from the National Library of Medicine (Pubmed) database and the Cochrane Library utilizing the search terms "Juvenile Myoclonic Epilepsy" and "sleep". A total of 160 papers' review, data extraction, and resolution of discrepancies were performed independently by two reviewers according to the PRISMA protocol and were registered in PROSPERO (CRD42023472439). A systematic review of 31 studies was conducted, encompassing various methodologies, including sleep questionnaires (Pittsburgh Sleep Quality Index (n = 13), Epworth Sleepiness Scale (n = 10)), polysomnography (n = 8), EEG (n = 9), actigraphy (n = 1), and transcranial magnetic stimulation (n = 1). Most studies were hospital-based (n = 31), cross-sectional (n = 11), and prospective (n = 25). Patients with JME exhibit a higher prevalence of sleep disturbances, worse quality of sleep (n = 4), daytime sleepiness (n = 2), sleep efficiency (n = 7), and increased sleep latency (n = 1) compared to controls. These disruptions are characterized by increased wakefulness (n = 3), frequent arousals (n = 3), decreased REM sleep (n = 2), and conflicting NREM sleep findings (n = 3). Additional sleep-related issues observed in JME patients include insomnia (n = 1) and increased prevalence of parasomnias such as nightmares and sleep talking. Periodic limb movement and obstructive sleep apnea are similar or less frequent (3/28). REM behavioral disorders and sleepwalking were not seen. Valproate showed conflicting effects on sleep (n = 7), while levetiracetam did not impact sleep (n = 1). These findings underlined the need for more sufficient evidence of sleep studies in JME. Future research should prioritize understanding the nature of sleep in JME and its impact on management.

Variation in prognosis and treatment outcome in juvenile myoclonic epilepsy: a Biology of Juvenile Myoclonic Epilepsy Consortium proposal for a practical definition and stratified medicine classifications

Reliable definitions, classifications and prognostic models are the cornerstones of stratified medicine, but none of the current classifications systems in epilepsy address prognostic or outcome issues. Although heterogeneity is widely acknowledged within epilepsy syndromes, the significance of variation in electroclinical features, comorbidities and treatment response, as they relate to diagnostic and prognostic purposes, has not been explored. In this paper, we aim to provide an evidence-based definition of juvenile myoclonic epilepsy showing that with a predefined and limited set of mandatory features, variation in juvenile myoclonic epilepsy phenotype can be exploited for prognostic purposes. Our study is based on clinical data collected by the Biology of Juvenile Myoclonic Epilepsy Consortium augmented by literature data. We review prognosis research on mortality and seizure remission, predictors of antiseizure medication resistance and selected adverse drug events to valproate, levetiracetam and lamotrigine. Based on our analysis, a simplified set of diagnostic criteria for juvenile myoclonic epilepsy includes the following: (i) myoclonic jerks as mandatory seizure type; (ii) a circadian timing for myoclonia not mandatory for the diagnosis of juvenile myoclonic epilepsy; (iii) age of onset ranging from 6 to 40 years; (iv) generalized EEG abnormalities; and (v) intelligence conforming to population distribution. We find sufficient evidence to propose a predictive model of antiseizure medication resistance that emphasises (i) absence seizures as the strongest stratifying factor with regard to antiseizure medication resistance or seizure freedom for both sexes and (ii) sex as a major stratifying factor, revealing elevated odds of antiseizure medication resistance that correlates to self-report of catamenial and stress-related factors including sleep deprivation. In women, there are reduced odds of antiseizure medication resistance associated with EEG-measured or self-reported photosensitivity. In conclusion, by applying a simplified set of criteria to define phenotypic variations of juvenile myoclonic epilepsy, our paper proposes an evidence-based definition and prognostic stratification of juvenile myoclonic epilepsy. Further studies in existing data sets of individual patient data would be helpful to replicate our findings, and prospective studies in inception cohorts will contribute to validate them in real-world practice for juvenile myoclonic epilepsy management.

Clinical Characteristics and Prognosis of Juvenile Myoclonic Epilepsy: Single-Center Retrospective Study

Juvenile myoclonic epilepsy (JME) is one of the most common idiopathic (genetic) generalized epilepsy syndromes. It occurs in healthy adolescents and is characterized by the triad of myoclonic jerks, generalized tonic-clonic seizures (GTCs), and absence seizures. The study's primary aim was to determine the demographic and clinical characteristics, family history of seizure, electroencephalogram findings, treatments, and short-term prognosis of patients diagnosed with JME. Patients diagnosed with JME at the Pediatric Neurology Department of Sağlık Bilimleri University Adana Numune Training and Research Hospitals were enrolled. Thirteen (30%) of 44 patients were male, whereas 31 (70%) were female, with a mean age at diagnosis of 14 ± 1.3 years. In total, 21 patients (48%) had a family history of epilepsy, and 14 patients (32%) had JME in their families. Those having a family history of JME seizures were identified at a younger age. Thirty (68%) patients presented with GTCs, while 14 (32%) presented with myoclonic seizures at the time of diagnosis. In the history, 98% of patients had myoclonus and one patient had an absence seizure. Patients with the first seizure type GTCs were diagnosed later, while patients with myoclonus were diagnosed earlier (p < 0,05). The most precipitating factors for seizures were sleep deprivation and stress. Thirty-eight (86%) of the EEGs recorded during the initial admission was abnormal. Valproic acid was administered to 32 patients (73%), while levetiracetam was administered to 12 patients (27%) as the initial treatment. Forty-one (93%) of the patients exhibited a complete response to the initial medication therapy, while forty (91%) of the patients received monotherapy, and only four (9%) received polytherapy. JME may be well-controlled epilepsy with early diagnosis and appropriate treatment. A family history of JME is also common among patients with JME. Patients with the myoclonus as a first seizure type are diagnosed earlier than GTCs because of family awareness. A family history of JME may facilitate the diagnosis of new cases in the family.

Seizure control in mono- and combination therapy in a cohort of patients with Idiopathic Generalized Epilepsy

Idiopathic Generalized Epilepsy (IGE) patients may not achieve optimal seizure control with monotherapy. Our goal was to evaluate the efficacy of combination therapy in a retrospective series of IGE patients receiving different antiseizure medication (ASM) regimens. We retrospectively identified all patients with adolescence onset IGE with typical clinical and EEG features from a single epilepsy specialist clinic from 2009 to 2020. We evaluated long-term seizure control, for VPA, LEV, LTG mono and combination therapy. We studied 59 patients. VPA was more commonly used in men (84%) than in women (44%) (p < 0.05). VPA was the initial drug of choice in 39% of patients, followed by LEV (22%) and LTG (14.9%). Thirty-nine patients (66.1%) achieved complete seizure control for at least one year. Fifty patients (84.7)% had partial control, without GTC occurrence, for at least one year. VPA was superior to LTG for complete seizure control (p = 0.03), but not for minor seizure control or pseudoresistance (p > 0.05). Combination therapy was superior to LEV and LTG monotherapy for complete control (p = 0.03), without differences for minor seizures and pseudoresistance outcomes (p > 0.05). Combination therapy not including VPA was also non-inferior to VPA monotherapy in all settings. Combination therapy was superior to LTG and LEV monotherapy in IGE, and may be equally effective including or not VPA. Combination therapy including LTG, LEV, and/or VPA is an effective treatment option after monotherapy failure with one of these ASM in IGE. Dual therapy with LEV-LTG should be considered in monotheraphy failure, to avoid fetal effects of in utero VPA exposure.

Epilepsy Syndromes: Current Classifications and Future Directions

This review describes the clinical presentations and treatment options for commonly recognized epilepsy syndromes in the pediatric age group, based on the 2017 International League Against Epilepsy classification. Structural epilepsies that are amenable to surgical intervention are discussed. Lastly, emerging technologies are reviewed that are expanding our knowledge of underlying epilepsy pathologies and will guide future syndromic classification systems including genetic testing and tissue repositories.

When should we obtain a routine EEG while managing people with epilepsy?

More than eight decades after its discovery, routine electroencephalogram (EEG) remains a safe, noninvasive, inexpensive, bedside test of neurological function. Knowing when a routine EEG should be obtained while managing people with epilepsy is a critical aspect of optimal care. Despite advances in neuroimaging techniques that aid diagnosis of structural lesions in the central nervous system, EEG continues to provide critical diagnostic evidence with implications on treatment. A routine EEG performed after a first unprovoked seizure can support a clinical diagnosis of epilepsy and differentiate those without epilepsy, classify an epilepsy syndrome to impart prognosis, and characterize seizures for antiseizure management. Despite a current viral pandemic, EEG services continue, and the value of routine EEG is unchanged.

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 and sleep

Juvenile myoclonic epilepsy (JME) is a sleep-related epilepsy syndrome, and only a few studies have addressed the relationship between JME and sleep disorders. In this review, the sleep characteristics of patients with JME were summarized based on the features of circadian rhythm, the possible cause of the early morning seizures, the common subjective and objective sleep disorders, the alterations in sleep architecture, and the effect of sleep deprivation and sodium valproate (VPA). The aims of this study were to summarize the interaction between JME and sleep, to reveal JME sleep characteristics, to encourage clinicians to focus on JME and sleep, to heighten the positive diagnosis rate, to guide the treatment, to improve the prognosis, and to enhance the daily life quality of patients with JME. At the same time, this study aimed to present existing controversies, in order to necessitate further studies.

Electroencephalography in the Diagnosis of Genetic Generalized Epilepsy Syndromes

Genetic generalized epilepsy (GGE) consists of several syndromes diagnosed and classified on the basis of clinical features and electroencephalographic (EEG) abnormalities. The main EEG feature of GGE is bilateral, synchronous, symmetric, and generalized spike-wave complex. Other classic EEG abnormalities are polyspikes, epileptiform K-complexes and sleep spindles, polyspike-wave discharges, occipital intermittent rhythmic delta activity, eye-closure sensitivity, fixation-off sensitivity, and photoparoxysmal response. However, admixed with typical changes, atypical epileptiform discharges are also commonly seen in GGE. There are circadian variations of generalized epileptiform discharges. Sleep, sleep deprivation, hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are often used as activation techniques to increase the diagnostic yield of EEG recordings. Reflex seizure-related EEG abnormalities can be elicited by the use of triggers such as cognitive tasks and pattern stimulation during the EEG recording in selected patients. Distinct electrographic abnormalities to help classification can be identified among different electroclinical syndromes.

Electroclinical aspects and therapy of Han patients with juvenile myoclonic epilepsy in northern China

OBJECTIVE

The objective of this study was to assess the electroclinical aspects and treatment of Han patients with juvenile myoclonic epilepsy (JME) in northern China.

METHODS

One hundred fifty-six outpatients with JME from six epilepsy centers, between January 2011 and June 2012, were followed up for at least two years. They underwent twenty-four-hour video-EEG recording. Brain imaging was performed using magnetic resonance imaging (MRI). Clinical aspects, electroencephalographic (EEG) features, and antiepileptic drugs (AEDs) received were reviewed.

RESULTS

Generalized tonic-clonic seizures (GTCS) were found in 150/156 patients. Delay of diagnosis was 4.60±9.92years. Photosensitivity was more common in eye closure condition during IPS in patients with JME; in addition, patients with JME with myoclonic seizures (MS) and GTCS as seizure types were likely to present photoparoxysmal responses (PPRs). The 82 nontreated patients showed a median latency to first interictal or ictal generalized spike-wave discharge (GSWD) of 50min (IQR: 22-102min). The first GSWDs were recorded in 63%, 76%, 90%, and 98% patients within one, two, three, and 4h, respectively; only 2% of patients had first GSWDs after 4h. One hundred eleven patients (111/156) chose extended-release valproate (VPA) at daily doses ≤1000mg. The percentages of seizure-free patients among MS, GTCS, and absence seizure (AS) groups were 88.3%, 99.0%, and 94.9%, respectively.

CONCLUSION

Photoparoxysmal responses were more common in patients with JME with MS and GTCS and rare in patients with JME with MS and AS in northern Chinese Han patients. Most patients with JME in northern China chose VPA as first therapeutic choice, and low dose (500 to 1000mg daily) of extended-release VPA may be an optimal choice for them. Video-EEG monitoring for at least 4h may be helpful in detecting the first interictal or ictal GSWD in patients with potential JME. Moreover, video-EEG monitoring performed at about 9 o'clock in the morning with patients in the awake state might be useful to find the first GSWD. For JME diagnosis, Class II criteria are more helpful than Class I counterparts, the latter yielding more missed diagnoses.

Is there a creative functional paradoxical facilitation in juvenile myoclonic epilepsy?

OBJECTIVE

In patients with juvenile myoclonic epilepsy (JME), a specific personality profile suggestive of frontal lobe dysfunctions has been described. From a neurobiological point of view, the frontal lobe seems to be crucial for creative processes, although the exact role remains unclear. The theory of creative paradoxical functional facilitation (PFF) assumes that disinhibited frontal lobe function can enhance creative abilities. The aim of the current study was to explore our hypothesis that JME is associated with higher artistic creativity based on the theory of PFF.

METHODS

We assessed 25 patients with JME aged 18 to 40years in regard to neuropsychological creativity testing. Results were compared with those of 25 age-, sex-, and level of education-matched healthy control subjects (HC) and patients with temporal lobe epilepsy (TLE). Creative abilities were assessed using two validated and standardized tests: 1) nonverbal: the incomplete figure task of Torrance Test of Creative Thinking and 2) verbal: verbal creativity test. Additionally, a basic assessment of fluid intelligence (test for problem solving) and frontal lobe function (trail-making test) was administered to all participants.

RESULTS

Verbal creativity was impaired in both groups with epilepsy compared with that in HC (specific score: JME vs. HC, p=0.008; TLE vs. HC, p=0.003). In regard to nonverbal creative abilities, both groups with epilepsy exhibited fair performance. Level of fluid intelligence was even in all groups (p=0.433). Only patients with JME showed deficits in the frontal lobe test of psychomotor speed (time in seconds: 67.7 JME vs. 54.6 TLE vs. 52.8 HC; p=0.045).

CONCLUSIONS

Overall, our study did not reveal increased creativity in JME. The current findings provide insights into creative abilities in two different epilepsy syndromes. Knowledge on specific neuropsychological strengths or deficits in patients with epilepsy may be useful for treatment or counseling.

Ophthalmoplegic migraine with isolated third cranial nerve palsy in a known case of juvenile myoclonic epilepsy

Among the various forms of migraine headaches, ophthalmoplegic migraine is an uncommon and rare form, the incidence of which is approximately 0.7 per million. It presents predominantly with headache and ophthalmoplegia. One of more cranial nerves can be affected, however the third cranial nerve is most often affected. As a result, symptoms wise, mydriasis and ptosis are commonly seen. Patients generally recover completely within a few days or weeks, however residual deficits are known to occur in a minority of patients. One of the common generalised epilepsy syndromes is the juvenile myoclonic epilepsy (JME), its prevalence being roughly up to 10% of all patients with epilepsy. It usually begins in the second decade of life. Generalised tonic-clonic seizures myoclonic jerks absences constitute the main seizure types in JME. Studies indicate a definite association of epilepsy with migraine headaches and a significant number of migraneurs are found to be epileptic. Conversely, patients with epilepsy are two times more likely to have migraine, as compared to their first degree relatives without migraine. We report a known case of a female patient of JME having a history of classical migraine with aura presenting to us with headache and ophthalmoplegia. She was extensively evaluated to rule out other causes of isolated third cranial nerve palsy, with all the investigations being negative for any obvious cause. She was treated with non-steroidal anti-inflammatory drugs for the acute attack and was subsequently put on antimigraine medication, propranolol during her hospital stay, with which her ptosis recovered completely after 2 weeks. The patient was later started on tablet divalproex sodium, which the patient continues to take on a long-term basis, especially because of its efficacy as an antimigraine prophylaxis agent and a potent drug against JME.

Neurophysiology of juvenile myoclonic epilepsy

Juvenile myclonic epilepsy (JME) can be firmly diagnosed by a careful interview of the patient focusing on the seizures and by the EEG with the help, if necessary, of long-term video-EEG monitoring using sleep and/or sleep deprivation. Background activity is normal. The interictal EEG shows diffuse or generalized spike-wave (SW) and polyspike-wave (PSW) discharges. In some patients, non-specific changes or misleading features such as focal changes are found. Changes are mostly seen at sleep onset and at awakening. Provoked awakenings are more likely to activate interictal paroxysmal abnormalities than spontaneous awakenings. The presence of a photoparoxysmal response with or without myoclonic jerks (MJ) is common (30% of the cases). Myoclonic jerks are associated with a discharge of fast, irregular, generalized PSWs that predominate anteriorly. Myoclonic jerks appear to be associated with rhythmic EEG (spike) potentials at around 20Hz. These frequencies are in the range of movement-related fast sensorimotor cortex physiological rhythms. The application of jerk-locked averaging technique has provided findings consistent with a cortical origin of MJ. Paired TMS (transcranial magnetic stimulation) studies showed a defective intracortical inhibition, due to impaired GABA-A mediated mechanisms. In this review, we present the EEG characteristics of JME with particular emphasis on the pathophysiology of MJ and on the role of sleep deprivation on interictal and ictal changes.

Chronodependency and provocative factors in juvenile myoclonic epilepsy

In juvenile myoclonic epilepsy (JME), occurrence of seizures and epileptiform EEG discharges is influenced by internal and external factors. The most important internal factor is the chronodependency: the occurrence of myoclonic jerks in the early morning is one of the hallmarks of JME. Approximately two-thirds of the patients with JME report that seizures are provoked by a variety of general factors like stress, fatigue, fever, and sleep and more specific precipitants like flashing sunlight, music, reading, thinking, and excess alcohol. The prevalence rate of photosensitivity (photoparoxysmal EEG response) in patients with JME ranges from 8 to 90%; it is seen more often in females and adolescents and depends on drug use. Since both JME and photosensitivity are connected with generalized types of epilepsy and myoclonus, the two traits are comorbid for that reason. Epileptiform EEG discharges can be provoked by other activation methods: sleep, hyperventilation, and specific cognitive tasks. Attention seems to have a non-specific, inhibitory effect of the epileptiform discharges. Hyperventilation can induce absence seizures in patients with JME, while cognitive tasks are efficient in precipitating myoclonic seizures. This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?

Interrelationship of sleep and juvenile myoclonic epilepsy (JME): a sleep questionnaire-, EEG-, and polysomnography (PSG)-based prospective case-control study

We studied the effects of 'epilepsy on sleep and its architecture' and 'sleep on the occurrence and distribution of interictal epileptiform discharges (ED)' using 'sleep questionnaires', 'EEG', and 'PSG' in patients with JME. Forty patients with JME [20 on valproate (Group I - 20.8±4.0 years; M: F=9:11) and 20 drug-naïve (Group II - 24.4±6.7 years; M: F=9:11)] and 20 controls (M: F=9:11; age: 23.5±4.7 years) underwent assessment with Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), overnight PSG, and scalp-EEG. Epileptiform discharges (EDs) were quantified in different sleep stages. The 'ED Index' was derived as number of EDs/min per stage. Statistical Package for the Social Sciences (SPSS) vs. 11 was used for statistical analysis. A 'p' <0.05 was considered as statistically significant. There was poor sleep quality in patients compared to controls (p=0.02), while there was no significant difference in ESS scores between the groups. The PSG parameters were comparable in both groups. Routine EEG revealed EDs in 22/40 (Group I: 7 and Group II: 15) patients. Thirty-five patients had EDs in various sleep stages during PSG (Group I: 17 and Group II: 18): N1 - Group I: 9 and Group II: 14, N2 - Group I: 14 and Group II: 14, N3 - Group I: 14 and Group II: 10, and REM - Group I: 9 and Group II: 11. The ED Index was higher during N2/N3 in Group I and N1/REM in Group II. The epileptiform discharges were frequently associated with arousals in N1/REM and K-complexes in N2. There was no other significant difference between Groups I and II. In conclusion, there was poor sleep quality in patients with JME compared to controls, especially those on valproate who had altered sleep architecture. Epileptiform activity was observed more often in sleep than wakefulness. Sleep stages had variable effect on epileptiform discharges with light sleep having a facilitatory effect in the drug-naïve group and slow wave sleep having a facilitatory effect in the valproate group.

[Juvenile myoclonic epilepsy]

BACKGROUND

Juvenile myoclonic epilepsy (JME) is a generalised epilepsy with seizure onset in youth. The aim of this review is to present updated knowledge about the etiology, diagnosis and treatment of JME.

MATERIAL AND METHOD

The review is based on a judicious selection of original English language articles, meta-analyses, and reviews found in PubMed, and the authors' own experience with the patient group.

RESULTS

Seizure onset occurs in adolescence. All have myoclonias, about 90 % have generalized tonic-clonic seizures, and one third have absences. Myoclonic jerks are frequently the debut symptom, while tonic-clonic seizures appear later on. Patients are particularly susceptible to seizures shortly after waking. It is important to ask specifically about myoclonias as most patients do not report jerks spontaneously. The electroencephalograms of 44-81 % of the patients show discharges of 4-6 Hz polyspike waves. Focal EEG abnormalities may be seen in about 30 %. When patients are treated with valproate and seizure-precipitating factors are avoided, especially sleep deprivation, about 80 % become seizure-free. Lamotrigine and levetiracetam are alternative therapies for women of childbearing age. Attempts to taper off the medication after several years of seizure freedom entail a high risk of seizure relapse.

INTERPRETATION

As there may be features of focal epilepsy in the seizure semiology and/or the EEGs, it may be difficult to diagnose JME. Thus, many patients are misdiagnosed as having a focal epilepsy and are given antiepileptic drugs that may aggravate the tendency to seizures.

The electroencephalogram of idiopathic generalized epilepsy

Idiopathic generalized epilepsy (IGE) is classified into several subsyndromes based on clinical and electroencephalography (EEG) features. The EEG signature of IGE is bisynchronous, symmetric, and generalized spike-wave complex; although focal, irregular, and so called "fragments" of discharges are not uncommon. Other characteristic EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, and photoparoxysmal response. Both human and animal data suggest involvement of the thalamus and the cortex in the generation of spike-wave discharges in IGE. Circadian variations of generalized epileptiform discharges are well described, and these can be useful in diagnostic confirmation. Those discharges tend to occur more often after awakening and during cyclic alternating pattern phase-A of non-rapid eye movement sleep. Activation procedures such as hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are useful techniques to increase the yield of both interictal and ictal EEG abnormalities. Although not in routine use, specific triggers such as pattern stimulation and cognitive tasks may also be of value in eliciting rare reflex seizure-related EEG abnormalities. Variations of EEG abnormalities are evident between different electroclinical syndromes. EEG is also affected by certain external as well as internal factors, which should be borne in mind when interpreting EEG studies in IGE.

Headache in juvenile myoclonic epilepsy

The objective of this study was to assess the prevalence of and risk factors for primary headaches in juvenile myoclonic epilepsy (JME). Headache was classified in 75 patients with JME using a questionnaire, and its prevalence was correlated with the literature on the general population and clinical data. Headache was present in 47 patients. Thirty-one had migraine [20 migraine without aura (MO), 11 migraine with aura (MA)]. Fourteen patients with migraine had tension-type headache (TTH) in addition. Sixteen had only TTH. Comparison with the general population revealed a significantly higher prevalence of migraine (RR 4.4), MO (3.6), MA (7.3) and TTH (3.4) in JME. Risk factors for migraine and MO were female gender and for MA family history of migraine in first-degree relatives. Migraine and MA were associated with fairly controlled generalized tonic clonic seizures, MO with absences. Together with its strong genetic background, JME appears to be an attractive homogenous subtype of epilepsy for genetic research on migraine.

Myoclonus

Myoclonus can be classified as physiologic, essential, epileptic, and symptomatic. Animal models of myoclonus include DDT and posthypoxic myoclonus in the rat. 5-Hydrotryptophan, clonazepam, and valproic acid suppress myoclonus induced by posthypoxia. The diagnostic evaluation of myoclonus is complex and involves an extensive work-up including basic electrolytes, glucose, renal and hepatic function tests, paraneoplastic antibodies, drug and toxicology screens, thyroid antibody and function studies, neurophysiology testing, imaging, and tests for malabsorption disorders, assays for enzyme deficiencies, tissue biopsy, copper studies, alpha-fetoprotein, cytogenetic analysis, radiosensitivity DNA synthesis, genetic testing for inherited disorders, and mitochondrial function studies. Treatment of myoclonus is targeted to the underlying disorder. If myoclonus physiology cannot be demonstrated, treatment should be aimed at the common pattern of symptoms. If the diagnosis is not known, treatment could be directed empirically at cortical myoclonus as the most common physiology. In cortical myoclonus, the most effective drugs are sodium valproic acid, clonazepam, levetiracetam, and piracetam. For cortical-subcortical myoclonus, valproic acid is the drug of choice. Here, lamotrigine can be used either alone or in combination with valproic acid. Ethosuximide, levetiracetam, or zonisamide can also be used as adjunct therapy with valproic acid. A ketogenic diet can be considered if everything else fails. Subcortical-nonsegmental myoclonus may respond to clonazepam and deep-brain stimulation. Rituximab, adrenocorticotropic hormone, high-dose dexamethasone pulse, or plasmapheresis have been reported to improve opsoclonus myoclonus syndrome. Reticular reflex myoclonus can be treated with clonazepam, diazepam and 5-hydrotryptophan. For palatal myoclonus, a variety of drugs have been used.

Juvenile myoclonic epilepsy: epidemiology, pathophysiology, and management

Juvenile myoclonic epilepsy (JME) is a common epilepsy syndrome that begins most frequently in the early teenage years. It is officially classified as a type of idiopathic generalized epilepsy and is often under-recognized or misdiagnosed. This syndrome has a strong genetic component with multiple gene mutations being associated with the clinical presentation. Based upon genetic associations, there may be multiple pathophysiologic mechanisms for the disorder; the pathophysiology has not been clearly defined. A diagnosis of JME is made using the clinical history and EEG findings. Valproic acid is the primary antiepileptic drug (AED) used for JME, but some newer AEDs may be effective alternatives. Selection of an appropriate AED is essential to the proper management of JME, because of the possibility of exacerbation of seizures by some AEDs and the adverse effect profiles of effective drugs. It is important for clinicians to understand JME to correctly diagnose and manage patients with this syndrome.

Murine models of inherited monoaminergic and GABAergic neurotransmitter disorders

Monoamine and amino acid neurotransmitters perform diverse biological functions in mammals, including the regulation of inhibitory/excitatory neurotransmission in the brain and spinal cord, movement and sleep, autonomic function, mood and reward, and numerous other processes. The primary transmitters involved include dopamine, serotonin, epinephrine, norepinephrine and γ-aminobutyric acid (GABA). With the exception of the amino acid transmitter GABA, the cofactor integrating these systems is tetrahydrobiopterin, an oxidizable intermediate found in high concentrations in dopaminergic neurons. With growing awareness of the clinical phenotypes, expanding numbers of patients with monoaminergic and GABAergic neurotransmitter disorders are being identified. For some people, therapeutic intervention demonstrates remarkably positive benefits; conversely, for most other disorders therapy offers limited efficacy. Decoding of the complete mouse genome, coupled with methodology capable of ablating specific genes, has revolutionized how geneticists understand and treat human genetic disease. This is well-exemplified in the disorders covered in this review, which focuses predominantly on monoaminergic (tetrahydrobiopterin-dependent) and GABAergic signaling neurotransmitter disorders.

Self-perception of factors that precipitate or inhibit seizures in juvenile myoclonic epilepsy

PURPOSE

To assess self-perception of factors that precipitate or inhibit seizures in patients with juvenile myoclonic epilepsy (JME).

PATIENTS AND METHODS

Thirty-six males and 39 females with JME and mean age of 25.8+/-8.7 years were analysed. All patients completed a standardized questionnaire to assess for the presence or absence of precipitant or inhibitory factors for their seizures in a face-to-face interview. These data were statistically analysed through logistic and linear regression models and Phi coefficient.

RESULTS

Ninety-two percent of the patients identified at least one precipitating factor (PF). In order of frequency the following PFs were recorded: stress (83%), sleep deprivation (77%), specific thoughts/mental concentration (23%), performance of hand activities and complex finger movements (20%), flashing lights and playing games (15%), speaking out in public (11%) and alcohol intake (11%), reading (7%), calculating and writing (5%), playing musical instruments (4%), drawing (3%), and specific types of music (1%). Menstrual cycle was the third most important PF in the women (33%). Although PFs were easily recognized, 77% of the patients stated that they were unable to avoid the occurrence of the seizures.

CONCLUSIONS

Structured questionnaire is useful in stimulating patients to self-report seizure precipitants. Patients with higher education and uncontrolled seizures identified them more easily. The presence of a significant number of uncommon PFs, such as mental and motor hand tasks, considered uncommon for other epileptic syndromes, suggests that the role of these factors may be under-recognized in JME.

Genome-wide linkage scan of epilepsy-related photoparoxysmal electroencephalographic response: evidence for linkage on chromosomes 7q32 and 16p13

Photoparoxysmal response (PPR) is an abnormal visual sensitivity of the brain in reaction to intermittent photic stimulation. It is an epilepsy-related electroencephalographic trait with high prevalence in idiopathic epilepsies, especially in common idiopathic generalized epilepsies (IGEs), such as childhood absence epilepsy and juvenile myoclonic epilepsy. This degree of co-morbidity suggests that PPR may be involved in the predisposition to IGE. The identification of genes for PPR would, therefore, aid the dissection of the genetic basis of IGE. Sixteen PPR-multiplex families were collected to conduct a genome-wide linkage scan using broad (all PPR types) and narrow (exclusion of PPR types I and II and the occipital epilepsy cases) models of affectedness for PPR. We found an empirical genome-wide significance for parametric (HLOD) and non-parametric (NPL) linkage (Pgw(HLOD)=0.004 and Pgw(NPL)=0.01) for two respective chromosomal regions, 7q32 at D7S1804 (HLOD=3.47 with alpha=1, P(NPL)=3.39x10(-5)) and 16p13 at D16S3395 (HLOD=2.44 with alpha=1, P(NPL)=7.91x10(-5)). These two genomic regions contain genes that are important for the neuromodulation of cortical dynamics and may represent good targets for candidate-gene studies. Our study identified two susceptibility loci for PPR, which may be related to the underlying myoclonic epilepsy phenotype present in the families studied.

Adolescent seizures and epilepsy syndromes

Specific epilepsy syndromes begin during adolescence and create a significant neurologic burden. Knowledge of these syndromes has important treatment and prognostic implications, which usually extend into adulthood. Little is known about the effect of menarche on seizures, even though a relationship of seizures to the menstrual cycle has been observed for many years. In general, puberty is not thought to influence seizure frequency. However, estrogen is thought to activate epileptiform activity; testosterone may decrease seizure activity; and progesterone decreases epileptiform discharges. These effects are mediated by effecting gammaaminobutyric acid (GABA) transmission. Idiopathic generalized epilepsies are the most frequent group with adolescent onset. These are probably polygenic in origin and represent a biologic continuum. Juvenile myoclonic epilepsy (JME) is the most common form. This contrasts with a variety of progressive myoclonic epilepsies that also are first seen in adolescence and have a genetic origin and specific treatments. Finally, although temporal lobe epilepsy associated with hippocampal sclerosis may have its origin in childhood, often the child does not come to surgical evaluation until adolescence or young adulthood. The characteristic clinical history, seizure semiology, and magnetic resonance imaging findings have allowed a discrete epilepsy syndrome to be established. Applying these same criteria to children and adolescents reveals that hippocampal sclerosis is the most common lesion responsible for their intractable temporal lobe epilepsy. Hippocampal sclerosis is probably underdiagnosed in children. The safety and efficacy of epilepsy surgery in the age group is excellent. Knowledge of the epilepsy syndromes that remit before adolescence, may persist into adolescence, or begin in adolescence is central to the treatment of this age group.