Myoclonic Seizures (myoclonic + seizures)

Distribution by Scientific Domains


Selected Abstracts


Predictive Clinical Factors for the Differential Diagnosis of Childhood Extratemporal Seizures

EPILEPSIA, Issue 8 2005
András Fogarasi
Summary:,Purpose: To describe predictive clinical factors for the differentiation between childhood frontal lobe epilepsy (FLE) and posterior cortex epilepsy (PCE). Methods: Two independent, blinded investigators analyzed 177 seizures from 35 children (aged 11 months to 12 years) with extratemporal epilepsy selected by postoperative seizure-free outcome. Semiologic seizure components and different periictal signs were observed. Age at onset, auras, seizure frequency, and nocturnal dominance, as well as surgical and histopathologic data, were collected from medical charts. Results: Twenty patients had FLE, and 15 had PCE. Patients from both groups had daily seizures without significant differences in frequency but with higher nocturnal dominance in children with FLE (p < 0.05). Visual aura, nystagmus, and versive seizure were observed exclusively in the PCE group, whereas somatosensory aura and hypermotor seizures appeared only in FLE. Tonic seizures were significantly more frequent in FLE (p < 0.01), whereas the presence of clonic seizure (FLE; p = 0.07) and postictal nose-wiping (PCE; p = 0.05) showed only a trend to localize the seizure-onset zone. Myoclonic seizures, epileptic spasms, psychomotor seizures, atonic seizures, oral and manual automatisms, as well as vocalization and eye deviation appeared in both groups without significant differences in their frequency. Conclusions: Characteristic features described in adults' extratemporal epilepsies were frequently missing during childhood seizures, especially in infants and preschool children. Ictal features help only a little in differentiating childhood FLE from PCE. Nocturnal appearance and the type of aura have high localizing value; therefore an accurate history taking is still an essential element of pediatric presurgical evaluation. [source]


Subacute sclerosing panencephalitis: an update

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2010
JOSE GUTIERREZ
Subacute sclerosing panencephalitis (SSPE) is a chronic encephalitis occurring after infection with measles virus. The prevalence of the disease varies depending on uptake of measles vaccination, with the virus disproportionally affecting regions with low vaccination rates. The physiopathology of the disease is not fully understood; however, there is evidence that it involves factors that favour humoral over cellular immune response against the virus. As a result, the virus is able to infect the neurons and to survive in a latent form for years. The clinical manifestations occur, on average, 6 years after measles virus infection. The onset of SSPE is insidious, and psychiatric manifestations are prominent. Subsequently, myoclonic seizures usually lead to a final stage of akinetic mutism. The diagnosis is clinical, supported by periodic complexes on electroencephalography, brain imaging suggestive of demyelination, and immunological evidence of measles infection. Management of the disease includes seizure control and avoidance of secondary complications associated with the progressive disability. Trials of treatment with interferon, ribavirin, and isoprinosine using different methodologies have reported beneficial results. However, the disease shows relentless progression; only 5% of individuals with SSPE undergo spontaneous remission, with the remaining 95% dying within 5 years of diagnosis. [source]


Generalized-onset seizures with secondary focal evolution

EPILEPSIA, Issue 7 2009
Randy Williamson
Summary The international seizure classification recognizes that partial-onset seizures can become secondarily generalized, but generalized-onset seizures are expected to remain generalized. We report six patients who had recorded seizures with generalized onset, but subsequent evolution into a focal discharge. The clinical seizure onset was generalized absence or myoclonic, and the most common subsequent clinical pattern was prolonged behavioral arrest with mild automatisms, and then postictal confusion. The ictal discharge started with generalized spike-and-wave activity and then acquired a focal predominance. Interictal epileptiform activity was generalized. There were no focal magnetic resonance imaging abnormalities. Four patients were misdiagnosed with complex partial seizures. All patients were initially refractory, but three became seizure-free and three improved after treatment with antiepileptic medications appropriate for absence or myoclonic seizures. Generalized-onset seizures that acquire focal features are easily misdiagnosed as complex partial. These seizures have a more favorable response to medications effective against generalized absence and myoclonic seizures. [source]


Clinical picture of EPM1-Unverricht-Lundborg disease

EPILEPSIA, Issue 4 2008
Reetta Kälviäinen
Summary Unverricht-Lundborg disease (ULD), progressive myoclonic epilepsy type 1 (EPM1, OMIM254800), is an autosomal recessively inherited neurodegenerative disorder characterized by age of onset from 6 to 16 years, stimulus-sensitive myoclonus, and tonic,clonic epileptic seizures. Some years after the onset ataxia, incoordination, intentional tremor, and dysarthria develop. Individuals with EPM1 are mentally alert but show emotional lability, depression, and mild decline in intellectual performance over time. The diagnosis of EPM1 can be confirmed by identifying disease-causing mutations in a cysteine protease inhibitor cystatin B (CSTB) gene. Symptomatic pharmacologic and rehabilitative management, including psychosocial support, are the mainstay of EPM1 patients' care. Valproic acid, the first drug of choice, diminishes myoclonus and the frequency of generalized seizures. Clonazepam and high-dose piracetam are used to treat myoclonus, whereas levetiracetam seems to be effective for both myoclonus and generalized seizures. There are a number of agents that aggravate clinical course of EPM1 such as phenytoin aggravating the associated neurologic symptoms or even accelerating cerebellar degeneration. Sodium channel blockers (carbamazepine, oxcarbazepine) and GABAergic drugs (tiagabine, vigabatrin) as well as gabapentin and pregabalin may aggravate myoclonus and myoclonic seizures. EPM1 patients need lifelong clinical follow-up, including evaluation of the drug-treatment and comprehensive rehabilitation. [source]


A Screening test for the prediction of Dravet syndrome before one year of age

EPILEPSIA, Issue 4 2008
Junri Hattori
Summary Purpose: Our aim was to develop a screening test to predict Dravet syndrome before the first birthday based on the clinical characteristics of infants and the SCN1A mutation analysis. Methods: Ninety-six patients who experienced febrile seizures before the age of one were enrolled. The patients were divided into two groups,the Dravet syndrome group (n = 46) and the non-Dravet syndrome group (n = 50). We compared the clinical characteristics before one year of age of the two groups. We analyzed all coding exons of the SCN1A gene by the direct sequencing method. Scores from 0 to 3 were assigned to each risk factor based on the odds ratio and p-value. Results: An age of onset of febrile seizure , 7 months, a total number of seizures , 5, and prolonged seizures lasting more than 10 min. were regarded as significant risk factors for Dravet syndrome. Other factors highly predictive of this syndrome were hemiconvulsions, partial seizures, myoclonic seizures, and hot water,induced seizures. A total clinical score of six or above was the cutoff value indicating a high risk of Dravet syndrome. SCN1A missense and truncated mutations were detected significantly more often in the Dravet syndrome group than in the non-Dravet syndrome group. Discussion: This simple screening test was designed to be used by general pediatricians. It could help to predict Dravet syndrome before one year of age. If the sum of the clinical risk score is , 6, then the performance of an SCN1A mutation analysis is recommended. [source]


Altered Tryptophan Metabolism in the Brain of Cystatin B -Deficient Mice: A Model System for Progressive Myoclonus Epilepsy

EPILEPSIA, Issue 10 2006
Annika Vaarmann
Summary:,Purpose: Progressive myoclonus epilepsy of the Unverricht,Lundborg type (EPM1) is a rare neurologic disorder, associated with mutations in the Cystatin B (Cstb) gene. Mice lacking Cstb, a cysteine protease inhibitor of the cathepsine family of proteases, provide a mammalian model for EPM1 by displaying similarly progressive ataxia, myoclonic seizures, and neurodegeneration. However, the linkage of Cstb deficit on the molecular level to pathologic features like myoclonic jerks or tonic,clonic seizures has remained unclear. We examined the tryptophan (TRP) metabolism, along the serotonin (5HT) and kynurenine (KYN) pathway in the brain of Cstb -deficient mice, in relation to their possible involvement in the seizure phenotype. Methods: TRP and its metabolites, along the 5HT and KYN pathways, were assayed in brain tissue by high-pressure liquid chromatography (HPLC) with electrochemical detection. The inverted wire grid and mild handling tests were used for evaluation of ataxia and myoclonic activity. Results: The Cstb -deficient mice had constitutively increased TRP, 5HT, and 5-hydroxyindole acetic acid (5HIAA) levels in the cerebral cortex and cerebellum and increased levels of KYN in the cerebellum. These neurochemical changes were accompanied with ataxia and an apparent myoclonic phenotype among the Cstb -deficient mice. Conclusions: Our findings suggest that secondary processes (i.e., overstimulation of serotoninergic transmission) on the cellular level, initiated by Cstb deficiency in specific brain regions, may be responsible for the myoclonic/seizure phenotype in EPM1. [source]


Symptomatic Epilepsies Imitating Idiopathic Generalized Epilepsies

EPILEPSIA, Issue 2005
Hirokazu Oguni
Summary:, The diagnosis of idiopathic generalized epilepsies (IGEs) is not generally difficult if one follows the clinical and electroencephalogram (EEG) definitions of each subsyndrome that constitutes IGEs. In contrast, symptomatic epilepsies develop based on organic brain lesions and are easily diagnosed by the presence of developmental delay, neurologic abnormalities, and a characteristic seizure and EEG pattern. However, in clinical practice, it is sometimes difficult to differentiate IGEs from symptomatic epilepsies, especially when the clinical course from the onset of epilepsy is too short to exhibit typical clinical and EEG findings of either epilepsy type, or when patients with symptomatic epilepsies have atypical features that imitate the clinical characteristics of IGEs. The neurodegenerative or metabolic disorders at times start during the clinical course with epileptic seizures and later show typical neurologic abnormalities. The newly recognized metabolic disorder of glucose transporter type 1 deficiency syndrome (Glut-1 DS) may start with myoclonic seizures at an age of less than 1 year and imitate benign myoclonic epilepsy in infancy early in the clinical course. Progressive myoclonus epilepsies (PMEs) that develop at 1,4 years of age at times imitate epilepsy with myoclonic-astatic seizures with respect to the presence of astatic seizures and an epileptic encephalopathic EEG pattern. In addition, young children with focal cortical dysplasia may also have similar clinical and EEG patterns, although the latter may become localized after treatment. Approximately 15% of patients with juvenile myoclonic epilepsy (JME) are resistant to antiepileptic drugs (AEDs) and may require extensive study to make a differential diagnosis from symptomatic epilepsies. PMEs that develop during adolescence may imitate JME early in the clinical course; however, a detailed history and the differentiation between myoclonic seizures and myoclonus would help to distinguish both conditions. The diagnosis of IGEs is very demanding for patients with atypical features with regard to seizure type, EEG findings, and response to appropriate AEDs. [source]


Focal Semiologic and Electroencephalographic Features in Patients with Juvenile Myoclonic Epilepsy

EPILEPSIA, Issue 10 2005
Naotaka Usui
Summary:,Purpose: A few reports have described focal electroencephalographic or clinical features or both of juvenile myoclonic epilepsy (JME), but without video-EEG documentation. We examined focal clinical and EEG features in patients with JME who underwent video-EEG monitoring. Methods: Twenty-six patients (nine males and 17 females) who had seizures recorded during video-EEG monitoring were included. Age at seizure onset was 0 to 22 years (mean, 12.3 years), and age at monitoring was 12 to 44 years (mean, 26.5 years). In one patient with left parietooccipital epilepsy, primary generalized tonic,clonic seizures developed after resection of the parietal tumor. Two patients had both temporal lobe epilepsy and JME. Videotaped seizures in each patient were analyzed. Interictal and ictal EEG also were analyzed for any focal features. Results: Focal semiologic features were observed in 12 (46%) of 26 patients. Six patients had focal myoclonic seizures, and two had Figure 4 sign: one with version to the left, and another had left version followed by Figure 4 sign, and left arm clonic seizure. Their ictal EEGs were generalized at onset but with a lateralized evolution over the right hemisphere. The patient who had both JME and left parietooccipital epilepsy, right arm clonic seizure, and Figure 4 sign was seen during a generalized EEG seizure. Interictally, one patient had temporal sharp waves, and another had run of spikes in the right frontal region. Conclusions: Fourteen (54%) of 26 patients with JME exhibited focal semiologic or electroencephalographic features or both. Video-EEG was essential in reaching a correct diagnosis and choosing an appropriate antiepileptic drug regimen. [source]


Classification of the Myoclonic Epilepsies

EPILEPSIA, Issue 2003
Ilo E. Leppik
Summary: The myoclonic epilepsies are a collection of syndromes in which myoclonic seizures are a prominent feature. Proper classification of a patient's syndrome is critical for appropriate treatment and prognosis. However, classification of such syndromes is often difficult because the terminology used to describe seizures can be confusing and inconsistent. Myoclonic epilepsy syndromes can be epileptic or nonepileptic and can also be divided into inherited and acquired forms. Progressive myoclonic epilepsy (PME) syndromes are the most severe of the myoclonic epilepsies. Diagnosis of PME syndromes on clinical grounds can be difficult, but advances in genetic testing have made diagnoses more accurate. Some other benign myoclonic epilepsy syndromes also have identified gene markers, which can aid in diagnosis. To accurately classify a patient's epilepsy syndrome, clinicians should use all available clinical laboratory tools appropriately. Improved accuracy of diagnosis for patients with myoclonic epilepsies should lead to more dependable prognoses and more effective treatment. [source]


Clinical and Electrographic Features of Epileptic Spasms Persisting Beyond the Second Year of Life

EPILEPSIA, Issue 6 2002
Márcio A. Sotero De Menezes
Summary: ,Purpose: Few reports detailing the electroclinical features of epileptic spasms persisting beyond infancy have been published. We sought to characterize this unique population further. Methods: We retrospectively reviewed the clinical and video-EEG data on 26 patients (4,17 years; mean, 93 months) with a confirmed diagnosis of epileptic spasms and who were evaluated at our tertiary referral center between 1993 and 2000. Results: In half of our cases, epileptic spasms were associated with disorders of neuronal migration, severe perinatal asphyxia, and genetic anomalies. Interictal EEGs showed generalized slowing in the majority of patients, and a slow-wave transient followed by an attenuation of the background amplitude was the most common ictal EEG pattern associated with an epileptic spasm (19 cases). Other seizure types (number of cases in parentheses) included tonic seizures with or without a preceding spasm (13), partial seizures (11), myoclonic seizures (11), generalized tonic,clonic seizures (six), atypical absence seizures (two), and atonic seizures (one). Cases with a more organized EEG background (especially with frequencies ,7 Hz) were more likely to have better cognition. Continued disorganization of the EEG background and persistence of hypsarrhythmia were associated with poor developmental outcome. Conclusions: Patients with epileptic spasms persisting beyond age 2 years constitute a truly refractory population, one that should be better recognized by clinicians. Interestingly, although many therapies resulted in a >50% reduction in seizures, neither neurocognitive function nor quality of life was substantially improved with intervention. The interictal EEG background is the most helpful in predicting neurologic outcome. [source]


Prognostic Significance of Failure of the Initial Antiepileptic Drug in Children with Absence Epilepsy

EPILEPSIA, Issue 6 2001
Elaine Wirrell
Summary: ,Purpose: In children with childhood absence epilepsy (CAE) and juvenile absence epilepsy (JAE), to determine the impact of failure of initial antiepileptic drug (AED) for lack of efficacy in eventual seizure control and long-term remission of epilepsy. Methods: Centralized EEG records for the province of Nova Scotia allowed identification of all children seen with CAE or JAE between 1977 and 1985. Information regarding success or failure of initial AED in fully controlling seizures and long-term seizure control and remission of epilepsy was collected by patient questionnaire and chart review. Results: Eighty-six of 92 eligible patients were followed up (75 CAE, 11 JAE). Initial AED treatment was successful in 52 (60%) of 86. Success tended to be greater for valproate (VPA) than for other AEDs (p = 0.07), and lower if generalized tonic,clonic or myoclonic seizures coexisted (p < 0.004 and p < 0.03). Terminal remission was more likely if the initial AED was successful than if it had failed (69% vs. 41%; p < 0.02). Compared with those in whom the initial AED was successful, subjects whose initial AED had failed were more likely to progress to juvenile myoclonic epilepsy (JME) at last follow-up (32% vs. 10%; p < 0.02) and to develop intractable epilepsy (17% vs. 2%; p < 0.04). Conclusions: Initial AED was successful in 60% of children with AE. If the first AED failed, the outcome was less favorable, with a lower rate of terminal remission and a higher rate of progression to JME and intractable epilepsy. [source]