Consensus on diagnosis and management of JME: From founder's observations to current trends.

An international workshop on juvenile myoclonic epilepsy (JME) was conducted in Avignon, France in May 2011. During that workshop, a group of 45 experts on JME, together with one of the founding fathers of the syndrome of JME ("Janz syndrome"), Prof. Dr. Dieter Janz from Berlin, reached a consensus on diagnostic criteria and management of JME. The international experts on JME proposed two sets of criteria, which will be helpful for both clinical and scientific purposes. Class I criteria encompass myoclonic jerks without loss of consciousness exclusively occurring on or after awakening and associated with typical generalized epileptiform EEG abnormalities, with an age of onset between 10 and 25. Class II criteria allow the inclusion of myoclonic jerks predominantly occurring after awakening, generalized epileptiform EEG abnormalities with or without concomitant myoclonic jerks, and a greater time window for age at onset (6-25years). For both sets of criteria, patients should have a clear history of myoclonic jerks predominantly occurring after awakening and an EEG with generalized epileptiform discharges supporting a diagnosis of idiopathic generalized epilepsy. Patients with JME require special management because their epilepsy starts in the vulnerable period of adolescence and, accordingly, they have lifestyle issues that typically increase the likelihood of seizures (sleep deprivation, exposure to stroboscopic flashes in discos, alcohol intake, etc.) with poor adherence to antiepileptic drugs (AEDs). Results of an inventory of the different clinical management strategies are given. This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?

Electroencephalographic characteristics of Dravet syndrome.

In Dravet syndrome, interictal and ictal electroencephalography (EEG) recording may remain misleading, and are not specifically altered. Moreover, there is a great polymorphism of clinical and EEG seizure types. Some can be observed in other epileptic syndromes, but others are more specific--particularly the peculiar unilateral seizures, the falsely generalized seizures, probably with a focal onset, and the unstable seizures. In some cases, the ictal manifestations are characterized by the persistent predominant recurrence of convulsive seizures, often induced by body temperature increase, eventually associated with partial complex seizures. The myoclonic events, absences with myoclonic component, obtundation status, and photosensitivity and/or pattern sensitivity are absent or appear relatively late and recur transiently for short periods. In these cases interictal EEG is characterized by the persistent paucity of paroxysmal discharges. In other cases, on a background of convulsive seizures and body temperature sensitivity, one may find a variable association of (1) myoclonic seizures of different types, (2) a strong sensitivity to light and pattern stimulations, with early onset and persistent in time. In these cases, interictal paroxysms and spontaneous and induced (intermittent photic stimulation, patterns, and eye closure) stimulation tend to appear early and to be frequent and persistent during the evolution. According to these electroclinical patterns it is possible to divide the population into two subsets, both sharing common genetic mechanisms but with a different clinical outcome.

Lennox-Gastaut syndrome in adulthood: clinical and EEG features.

PURPOSE: We performed a retrospective study to investigate seizure, EEG, social and cognitive outcome in adult LGS subjects. METHODS: We retrospectively evaluated 27 LGS patients aged 40-59 years. We assessed in particular the evolution of different seizure types and EEG findings, as well as cognitive and social outcome. RESULTS: During the early stages of the disease, all patients presented tonic seizures (TS) during wakefulness and sleep, 20/27 had atypical absences (AA), more rarely other seizure types. EEG showed slow background activity in 21/27 patients, diffuse slow spike-wave discharges (DSSW) during wakefulness in 22/27, and bursts of diffuse fast rhythms (DFR) in sleep in all patients. At last observation, 11 patients only had TS during wakefulness, but all still presented TS during sleep; AA persisted in 6 patients. EEG showed normal BA in 12/27 patients; only 7/27 still presented DSSW. On the contrary, sleep EEG showed the persistence of DFR in all. A moderate to severe cognitive impairment was observed in 26/27 patients. CONCLUSIONS: In adult LGS patients TS during sleep remain the major seizure type; moreover, a standard waking EEG may be normal. Thus, polysomnography represents the most important mean of investigation also in adult LGS patients.

Epilepsy with myoclonic absences.

Among the epileptic syndromes that are defined mainly on the basis of a characteristic seizure type, epilepsy with myoclonic absences (EMA) stands out as a somewhat controversial entity. This is because the sound and evident clinical characteristics on which it was identified some 30 years ago have evolved, mostly as a consequence of changes in the practical management of epilepsies and to the description of myoclonic components in a variety of other generalised epilepsies with absences. Myoclonic absences (MA) are described as typical absences with sudden onset and offset that are associated with generalised spike and wave (SW) discharges on the ECG, with distinctive traits. Clinically, absences are associated with axial hypertonia (the subject usually bends forward and slightly raises their shoulders and arms), and jerks synchronous with the SW discharges. Neurophysiologically, axial hypertonia and rhythmic jerks may be recorded on polygraphic surface electromyogram leads in association with the typical SW discharges; as such, despite an ECG, the diagnosis may be missed in the absence of video documentation of the seizure and/or adequate polygraphy. MA need to be distinguished from absences with other types of prominent myoclonic accompaniment (perioral, eyelid, limbs).The prognosis of EMA remains variable. Modern therapeutic combinations, such as valproic acid and ethosuximide, or valproic acid and lamotrigine, are usually effective; however, in a proportion of patients, seizures are resistant to drug treatment. These patients may experience cognitive deterioration and, in some cases, evolution towards a more severe form of epilepsy, including the Lennox-Gastaut syndrome. The more benign cases usually present with MA as the only seizure type, while patients who experience other seizures, especially generalised tonic-clonic seizures, in association with MA may have a less favourable outcome.

Epilepsy with myoclonic absences.

Epilepsy with myoclonic absences is characterized clinically by absences accompanied by marked, diffuse, rhythmical myoclonias, often associated with a progressive tonic contraction. The ictal EEG shows bilateral, synchronous and symmetrical spike and wave discharges repeated at 3 Hz (similar to that observed in typical absences of childhood absence epilepsy) in strict relation with myoclonias recorded on EMG. These seizures occur many times a day. Associated seizures are present in 2/3 of the cases, the most frequent association being GTCS in 45%. The age at onset is about 7 years. There is a male preponderance. The evolution is variable and seems to depend on the existence or not of GTCS. Classical cotherapy with valproate and ethosuximide with appropriate plasma levels is more efficient if myoclonic absences are non-associated with GTCS. In cases where GTCS are associated, there is often an unfavourable outcome, with persistence of myoclonic absences or with modification of the epilepsy with a possible evolution towards a generalized cryptogenic or symptomatic form.

Epilepsy and videogames.

Since the first case of videogame (VG) epilepsy was reported in 1981, many cases of seizures triggered by VGs were reported, not only in photosensitive, but also in non-photosensitive children and adolescents with epilepsy. We provide an overview of the literature with overall conclusions and recommendations regarding VG playing. Specific preventive measures concerning the physical characteristics of images included in commercially available VGs (flash rate, choice of colors, patterns, and contrast) can lead in the future to a clear decrease of this problem. In addition to the positive effect of such measures, the collaborative studies performed in France and in the rest of Europe have stressed the importance of a safe distance to the screen of > or = 2 m, and the less provocative role of 100-Hz screens.

Abnormal neuroimaging in patients with benign epilepsy with centrotemporal spikes.

PURPOSE: Neuroimaging procedures are usually unnecessary in benign epilepsy of childhood with centrotemporal spikes (BECTS) but are often performed before a specific diagnosis has been reached. By definition, BECTS occurs in normal children; however, recent reports have shown that it also can affect children with static brain lesions. We evaluated the prevalence of abnormal neuroimaging in BECTS and assessed whether the lesions had influenced the clinical and EEG expression of this epilepsy. RESULTS: Among 98 consecutive cases first referred between 1984 and 1999, neuroimaging had been performed in 71 (72%) [magnetic resonance imaging (MRI), 20; computed tomography (CT), 59; MRI+CT, eight]. In ten (14.8%), neuroradiologic procedures were abnormal: enlargement of lateral venticles in five cases including a shunted hydrocephalus in two (no etiology in one, neonatal intraventricular hemorrhage in one), a moderate ventricular dilation in one (neonatal distress), a slight ventricular dilation and hypersignal intensities in the white matter in one (premature birth at 27 weeks), and a moderate enlargement of the right temporal horn in one. A right hippocampal atrophy, a biopercular polymicrogyria, a cavum septum pellucidum, a small cystic lesion located in the epiphysis, and an agenesis of the corpus callosum with macrocrania also were observed once each. The outcome was benign in all, in accordance with the overall prognosis of BECTS. CONCLUSIONS: This study confirms that neuroimaging may be abnormal in patients with BECTS and shows that the presence of brain lesions has no influence on the prognosis. Conversely, BECTS can be diagnosed in patients with brain lesions with or without significant neurologic history or abnormalities.

Sleep-related, low voltage Rolandic and vertex spikes: an EEG marker of benignity in infancy-onset focal epilepsies.

Although benign forms of epilepsies with onset in infancy have recently been recognized, the occurrence of seizures in an infant or very young child is very often an event of great significance and the prognosis concerning both epilepsy and neuropsychological development must be guarded. No reliable clinical or electroencephalographic (EEG) markers that can predict the outcome have been described. In a retrospective series of 10 patients, we found a peculiar EEG pattern seen across sleep stages, but not in the waking state in infants whose first seizures appeared before the age of 1 year, and which were mostly complex focal. In all cases, follow-up showed a favourable outcome with complete seizure remission and no cognitive impairment. The specificity of these EEG changes was 100%, but the sensitivity was lower, since they were not seen in some of the infants with the same favourable outcome. We discuss the clinical similarities between our patients and those cases reported earlier by other authors as benign, non-familial or familial focal epilepsies, in whom, however, no interictal abnormalities had been seen on the EEG. Such EEG changes are probably specific to benign, self-limited, early onset focal epilepsies.