The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Christian Vollmar - One of the best experts on this subject based on the ideXlab platform.
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abnormal hippocampal structure and function in juvenile Myoclonic Epilepsy and unaffected siblings
Brain, 2019Co-Authors: Christian Vollmar, Britta Wandschneider, Lorenzo Caciagli, Fenglai XiaoAbstract:Juvenile Myoclonic Epilepsy is the most common genetic generalized Epilepsy syndrome, characterized by a complex polygenetic aetiology. Structural and functional MRI studies demonstrated mesial or lateral frontal cortical derangements and impaired fronto-cortico-subcortical connectivity in patients and their unaffected siblings. The presence of hippocampal abnormalities and associated memory deficits is controversial, and functional MRI studies in juvenile Myoclonic Epilepsy have not tested hippocampal activation. In this observational study, we implemented multi-modal MRI and neuropsychological data to investigate hippocampal structure and function in 37 patients with juvenile Myoclonic Epilepsy, 16 unaffected siblings and 20 healthy controls, comparable for age, gender, handedness and hemispheric dominance as assessed with language laterality indices. Automated hippocampal volumetry was complemented by validated qualitative and quantitative morphological criteria to detect hippocampal malrotation, assumed to represent a neurodevelopmental marker. Neuropsychological measures of verbal and visuo-spatial learning and an event-related verbal and visual memory functional MRI paradigm addressed mesiotemporal function. We detected a reduction of mean left hippocampal volume in patients and their siblings compared with controls (P < 0.01). Unilateral or bilateral hippocampal malrotation was identified in 51% of patients and 50% of siblings, against 15% of controls (P < 0.05). For bilateral hippocampi, quantitative markers of verticalization had significantly larger values in patients and siblings compared with controls (P < 0.05). In the patient subgroup, there was no relationship between structural measures and age at disease onset or degree of seizure control. No overt impairment of verbal and visual memory was identified with neuropsychological tests. Functional mapping highlighted atypical patterns of hippocampal activation, pointing to abnormal recruitment during verbal encoding in patients and their siblings [P < 0.05, familywise error (FWE)-corrected]. Subgroup analyses indicated distinct profiles of hypoactivation along the hippocampal long axis in juvenile Myoclonic Epilepsy patients with and without malrotation; patients with malrotation also exhibited reduced frontal recruitment for verbal memory, and more pronounced left posterior hippocampal involvement for visual memory. Linear models across the entire study cohort indicated significant associations between morphological markers of hippocampal positioning and hippocampal activation for verbal items (all P < 0.05, FWE-corrected). We demonstrate abnormalities of hippocampal volume, shape and positioning in patients with juvenile Myoclonic Epilepsy and their siblings, which are associated with reorganization of function and imply an underlying neurodevelopmental mechanism with expression during the prenatal stage. Co-segregation of abnormal hippocampal morphology in patients and their siblings is suggestive of a genetic imaging phenotype, independent of disease activity, and can be construed as a novel endophenotype of juvenile Myoclonic Epilepsy.
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motor co activation in siblings of patients with juvenile Myoclonic Epilepsy an imaging endophenotype
Brain, 2014Co-Authors: Britta Wandschneider, Christian Vollmar, Mark R Symms, John S Duncan, Maria Centeno, Pamela J Thompson, Matthias J KoeppAbstract:Juvenile Myoclonic Epilepsy is a heritable idiopathic generalized Epilepsy syndrome, characterized by Myoclonic jerks and frequently triggered by cognitive effort. Impairment of frontal lobe cognitive functions has been reported in patients with juvenile Myoclonic Epilepsy and their unaffected siblings. In a recent functional magnetic resonance imaging study we reported abnormal co-activation of the motor cortex and increased functional connectivity between the motor system and prefrontal cognitive networks during a working memory paradigm, providing an underlying mechanism for cognitively triggered jerks. In this study, we used the same task in 15 unaffected siblings (10 female; age range 18-65 years, median 40) of 11 of those patients with juvenile Myoclonic Epilepsy (six female; age range 22-54 years, median 35) and compared functional magnetic resonance imaging activations with 20 age- and gender-matched healthy control subjects (12 female; age range 23-46 years, median 30.5). Unaffected siblings showed abnormal primary motor cortex and supplementary motor area co-activation with increasing cognitive load, as well as increased task-related functional connectivity between motor and prefrontal cognitive networks, with a similar pattern to patients (P < 0.001 uncorrected; 20-voxel threshold extent). This finding in unaffected siblings suggests that altered motor system activation and functional connectivity is not medication- or seizure-related, but represents a potential underlying mechanism for impairment of frontal lobe functions in both patients and siblings, and so constitutes an endophenotype of juvenile Myoclonic Epilepsy.
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risk taking behavior in juvenile Myoclonic Epilepsy
Epilepsia, 2013Co-Authors: Christian Vollmar, Britta Wandschneider, Maria Centeno, J Stretton, Jonathan OmuircheartaighAbstract:Objective Patients with juvenile Myoclonic Epilepsy (JME) often present with risk-taking behavior, suggestive of frontal lobe dysfunction. Recent studies confirm functional and microstructural changes within the frontal lobes in JME. This study aimed at characterizing decision-making behavior in JME and its neuronal correlates using functional magnetic resonance imaging (fMRI).
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Motor system hyperconnectivity in juvenile Myoclonic Epilepsy: a cognitive functional magnetic resonance imaging study.
Brain : a journal of neurology, 2011Co-Authors: Christian Vollmar, Jonathan O'muircheartaigh, Gareth J Barker, Mark R Symms, Pamela Thompson, Veena Kumari, John S Duncan, Dieter Janz, Mark P Richardson, Matthias J KoeppAbstract:Juvenile Myoclonic Epilepsy is the most frequent idiopathic generalized Epilepsy syndrome. It is characterized by predominant Myoclonic jerks of upper limbs, often provoked by cognitive activities, and typically responsive to treatment with sodium valproate. Neurophysiological, neuropsychological and imaging studies in juvenile Myoclonic Epilepsy have consistently pointed towards subtle abnormalities in the medial frontal lobes. Using functional magnetic resonance imaging with an executive frontal lobe paradigm, we investigated cortical activation patterns and interaction between cortical regions in 30 patients with juvenile Myoclonic Epilepsy and 26 healthy controls. With increasing cognitive demand, patients showed increasing coactivation of the primary motor cortex and supplementary motor area. This effect was stronger in patients still suffering from seizures, and was not seen in healthy controls. Patients with juvenile Myoclonic Epilepsy showed increased functional connectivity between the motor system and frontoparietal cognitive networks. Furthermore, we found impaired deactivation of the default mode network during cognitive tasks with persistent activation in medial frontal and central regions in patients. Coactivation in the motor cortex and supplementary motor area with increasing cognitive load and increased functional coupling between the motor system and cognitive networks provide an explanation how cognitive effort can cause Myoclonic jerks in juvenile Myoclonic Epilepsy. The supplementary motor area represents the anatomical link between these two functional systems, and our findings may be the functional correlate of previously described structural abnormalities in the medial frontal lobe in juvenile Myoclonic Epilepsy.
Pierre Genton - One of the best experts on this subject based on the ideXlab platform.
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clinical aspects of juvenile Myoclonic Epilepsy
Epilepsy & Behavior, 2013Co-Authors: Pierre Genton, Pierre Thomas, Marco T. Medina, Dorothee Kasteleijnnolst G A Trenite, Javier SalaspuigAbstract:Abstract Juvenile Myoclonic Epilepsy (JME) is a recognizable, frequent epileptic syndrome. The most typical ictal phenomenon is bilateral myoclonia without loss of consciousness (M), with most patients also presenting with generalized tonic-clonic seizures (GTCSs) and some with absence seizures (ASs). The most striking features of JME are its onset around the time of puberty and the fact that seizure episodes occur after awakening from a sleep period or in the evening relaxation period and are facilitated by sleep deprivation and sudden arousal. Photic sensitivity is common in the EEG laboratory but uncommon or unrecognized in daily life. The clinical features of JME make it easy to diagnose. In recent years, awareness of JME has increased, and patients are often accurately diagnosed clinically before confirmation by EEG. The typical circumstance at diagnosis is a first GTCS episode, and one learns during the interview that the patient has had M in the morning for some time before the GTCS episode. There are only few differential diagnoses: the adolescent-onset progressive myoclonus epilepsies, or other forms of idiopathic generalized epilepsies of adolescence. With JME being so common, we propose that a first GTCS episode in a teenager should be considered as revealing JME until proven otherwise. This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?
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The history of juvenile Myoclonic Epilepsy
Epilepsy & Behavior, 2013Co-Authors: Pierre Genton, Philippe GelisseAbstract:Abstract Juvenile Myoclonic Epilepsy (JME) has been the subject of intensive research over the past 25 years. It was discovered stepwise in Switzerland and France in the 19th century, adequately described in Germany and Uruguay in the 1950s, and rediscovered in North America in the early 1980s. Juvenile Myoclonic Epilepsy represents the most common idiopathic Epilepsy syndrome. As a tribute to the primary author of the first extensive and detailed clinical description of JME, it is also called the Janz syndrome. Juvenile Myoclonic Epilepsy is an archetypical epileptic syndrome, with a fairly homogenous presentation and a still largely unknown etiology. Its clinical spectrum now includes cognitive and psychiatric symptoms as significant copathologies, and the elucidation of its probably multiple genetic mechanisms is an ongoing process. Juvenile Myoclonic Epilepsy may not qualify as a “benign” Epilepsy, but seizures in most patients can be managed adequately and patients will not suffer severe limitations in their lifetime expectations. This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?
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The history of juvenile Myoclonic Epilepsy.
Epilepsy & behavior : E&B, 2013Co-Authors: Pierre Genton, Philippe GelisseAbstract:Juvenile Myoclonic Epilepsy (JME) has been the subject of intensive research over the past 25years. It was discovered stepwise in Switzerland and France in the 19th century, adequately described in Germany and Uruguay in the 1950s, and rediscovered in North America in the early 1980s. Juvenile Myoclonic Epilepsy represents the most common idiopathic Epilepsy syndrome. As a tribute to the primary author of the first extensive and detailed clinical description of JME, it is also called the Janz syndrome. Juvenile Myoclonic Epilepsy is an archetypical epileptic syndrome, with a fairly homogenous presentation and a still largely unknown etiology. Its clinical spectrum now includes cognitive and psychiatric symptoms as significant copathologies, and the elucidation of its probably multiple genetic mechanisms is an ongoing process. Juvenile Myoclonic Epilepsy may not qualify as a "benign" Epilepsy, but seizures in most patients can be managed adequately and patients will not suffer severe limitations in their lifetime expectations.
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Management of juvenile Myoclonic Epilepsy
Epilepsy & Behavior, 2013Co-Authors: Arielle Crespel, Philippe Gelisse, Bettina Schmitz, Ronald C. Reed, Edoardo Ferlazzo, Judith Jerney, Pierre GentonAbstract:Juvenile Myoclonic Epilepsy (JME) is a common form of Epilepsy and a fairly lifelong disorder that may significantly lower a patient's expectations and potential for a full life. Luckily, it is also a highly treatable disorder, and up to 85% of patients with JME will enjoy satisfactory seizure control. Among anticonvulsants, valproate still stands out as the most efficacious drug, but may be poorly tolerated by some, and is considered unsafe for the fetuses of pregnant women. Alternatives have emerged in recent years, especially levetiracetam, but also topiramate, zonisamide or lamotrigine. In some cases, combination therapy may be useful or even required. One should not forget the potential aggravation induced not only by some commonly used anticonvulsants, especially carbamazepine and oxcarbazepine, but also, in some patients, by lamotrigine. In special settings, older drugs like benzodiazepines and barbiturates may be useful. But the management of JME should also include intervention in lifestyle, with strict avoidance of sleep deprivation and the management of copathologies, including the cognitive and psychiatric problems that are often encountered. With adequate management, there will only remain a small proportion of patients with uncontrolled Epilepsy and all of its related problems. Juvenile Myoclonic Epilepsy is a condition in which the clinician has a fair chance of significantly helping the patient with medication and counseling.
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Senile Myoclonic Epilepsy in Down syndrome: a video and EEG presentation of two cases
Epileptic disorders : international epilepsy journal with videotape, 2006Co-Authors: Roberto De Simone, Géraldine Daquin, Pierre GentonAbstract:Myoclonic Epilepsy is being increasingly recognized as a late-onset complication in middle-aged or elderly patients with Down syndrome, in association with cognitive decline. We show video and EEG recordings of two patients, both aged 56 years, diagnosed with this condition. At onset, Myoclonic Epilepsy in elderly DS patients may resemble, in its clinical expression, the classical juvenile Myoclonic Epilepsy with the characteristic occurrence of jerks on awakening. It is clearly associated with an Alzheimer-type dementia, and may also occur in non-DS patients with Alzheimer's disease: hence the possible denomination of "senile Myoclonic Epilepsy". [Published with video sequences].
Britta Wandschneider - One of the best experts on this subject based on the ideXlab platform.
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abnormal hippocampal structure and function in juvenile Myoclonic Epilepsy and unaffected siblings
Brain, 2019Co-Authors: Christian Vollmar, Britta Wandschneider, Lorenzo Caciagli, Fenglai XiaoAbstract:Juvenile Myoclonic Epilepsy is the most common genetic generalized Epilepsy syndrome, characterized by a complex polygenetic aetiology. Structural and functional MRI studies demonstrated mesial or lateral frontal cortical derangements and impaired fronto-cortico-subcortical connectivity in patients and their unaffected siblings. The presence of hippocampal abnormalities and associated memory deficits is controversial, and functional MRI studies in juvenile Myoclonic Epilepsy have not tested hippocampal activation. In this observational study, we implemented multi-modal MRI and neuropsychological data to investigate hippocampal structure and function in 37 patients with juvenile Myoclonic Epilepsy, 16 unaffected siblings and 20 healthy controls, comparable for age, gender, handedness and hemispheric dominance as assessed with language laterality indices. Automated hippocampal volumetry was complemented by validated qualitative and quantitative morphological criteria to detect hippocampal malrotation, assumed to represent a neurodevelopmental marker. Neuropsychological measures of verbal and visuo-spatial learning and an event-related verbal and visual memory functional MRI paradigm addressed mesiotemporal function. We detected a reduction of mean left hippocampal volume in patients and their siblings compared with controls (P < 0.01). Unilateral or bilateral hippocampal malrotation was identified in 51% of patients and 50% of siblings, against 15% of controls (P < 0.05). For bilateral hippocampi, quantitative markers of verticalization had significantly larger values in patients and siblings compared with controls (P < 0.05). In the patient subgroup, there was no relationship between structural measures and age at disease onset or degree of seizure control. No overt impairment of verbal and visual memory was identified with neuropsychological tests. Functional mapping highlighted atypical patterns of hippocampal activation, pointing to abnormal recruitment during verbal encoding in patients and their siblings [P < 0.05, familywise error (FWE)-corrected]. Subgroup analyses indicated distinct profiles of hypoactivation along the hippocampal long axis in juvenile Myoclonic Epilepsy patients with and without malrotation; patients with malrotation also exhibited reduced frontal recruitment for verbal memory, and more pronounced left posterior hippocampal involvement for visual memory. Linear models across the entire study cohort indicated significant associations between morphological markers of hippocampal positioning and hippocampal activation for verbal items (all P < 0.05, FWE-corrected). We demonstrate abnormalities of hippocampal volume, shape and positioning in patients with juvenile Myoclonic Epilepsy and their siblings, which are associated with reorganization of function and imply an underlying neurodevelopmental mechanism with expression during the prenatal stage. Co-segregation of abnormal hippocampal morphology in patients and their siblings is suggestive of a genetic imaging phenotype, independent of disease activity, and can be construed as a novel endophenotype of juvenile Myoclonic Epilepsy.
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motor co activation in siblings of patients with juvenile Myoclonic Epilepsy an imaging endophenotype
Brain, 2014Co-Authors: Britta Wandschneider, Christian Vollmar, Mark R Symms, John S Duncan, Maria Centeno, Pamela J Thompson, Matthias J KoeppAbstract:Juvenile Myoclonic Epilepsy is a heritable idiopathic generalized Epilepsy syndrome, characterized by Myoclonic jerks and frequently triggered by cognitive effort. Impairment of frontal lobe cognitive functions has been reported in patients with juvenile Myoclonic Epilepsy and their unaffected siblings. In a recent functional magnetic resonance imaging study we reported abnormal co-activation of the motor cortex and increased functional connectivity between the motor system and prefrontal cognitive networks during a working memory paradigm, providing an underlying mechanism for cognitively triggered jerks. In this study, we used the same task in 15 unaffected siblings (10 female; age range 18-65 years, median 40) of 11 of those patients with juvenile Myoclonic Epilepsy (six female; age range 22-54 years, median 35) and compared functional magnetic resonance imaging activations with 20 age- and gender-matched healthy control subjects (12 female; age range 23-46 years, median 30.5). Unaffected siblings showed abnormal primary motor cortex and supplementary motor area co-activation with increasing cognitive load, as well as increased task-related functional connectivity between motor and prefrontal cognitive networks, with a similar pattern to patients (P < 0.001 uncorrected; 20-voxel threshold extent). This finding in unaffected siblings suggests that altered motor system activation and functional connectivity is not medication- or seizure-related, but represents a potential underlying mechanism for impairment of frontal lobe functions in both patients and siblings, and so constitutes an endophenotype of juvenile Myoclonic Epilepsy.
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risk taking behavior in juvenile Myoclonic Epilepsy
Epilepsia, 2013Co-Authors: Christian Vollmar, Britta Wandschneider, Maria Centeno, J Stretton, Jonathan OmuircheartaighAbstract:Objective Patients with juvenile Myoclonic Epilepsy (JME) often present with risk-taking behavior, suggestive of frontal lobe dysfunction. Recent studies confirm functional and microstructural changes within the frontal lobes in JME. This study aimed at characterizing decision-making behavior in JME and its neuronal correlates using functional magnetic resonance imaging (fMRI).
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juvenile Myoclonic Epilepsy neuroimaging findings
Epilepsy & Behavior, 2013Co-Authors: Matthias J Koepp, Friedrich G Woermann, Ivanka Savic, Britta WandschneiderAbstract:Abstract Juvenile Myoclonic Epilepsy (JME) has been classified as a syndrome of idiopathic generalized Epilepsy and is characterized by specific types of seizures, showing a lack of pathology using magnetic resonance imaging (MRI) and computed tomography scanning. However, JME is associated with a particular personality profile, and behavioral and neuropsychological studies have suggested the possible involvement of frontal lobe dysfunction. The development of highly sensitive neuroimaging techniques has provided a means of elucidating the underlying mechanisms of JME. Positron emission tomography demonstrated metabolic and neurotransmitter changes in the dorsolateral prefrontal cortex reflecting the particular cognitive and behavioral profile of JME patients. 1H-magnetic resonance spectroscopy has shown evidence of thalamic dysfunction, which appears to be progressive. Such techniques provide evidence of multi-focal disease mechanisms, suggesting that JME is a frontal lobe variant of a multi-regional, thalamocortical ‘network’ Epilepsy, rather than a generalized Epilepsy syndrome. Quantitative MRI revealed significant abnormalities of cortical gray matter in medial frontal areas close to the supplementary motor area and diffusion abnormalities with increased functional coupling between the motor and prefrontal cognitive systems. This altered structural connectivity of the supplementary motor area provides an explanatory framework for the particular imaging findings, seizure type, and seizure‐provoking mechanisms in JME. This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?
Mary E O'regan - One of the best experts on this subject based on the ideXlab platform.
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Developmental outcome in benign Myoclonic Epilepsy in infancy and reflex Myoclonic Epilepsy in infancy: a literature review and six new cases.
Epilepsy research, 2006Co-Authors: Sameer M Zuberi, Mary E O'reganAbstract:Benign Myoclonic Epilepsy in infancy is a rare syndrome with just over 100 cases reported since the first syndromic description by Dravet and Bureau [Dravet, C., Bureau, M., 1981. The benign Myoclonic Epilepsy of infancy. Rev. Elecroencephalogr. Neurophysiol. Clin. 11, 438-444]. This includes 23 infants with reflex Myoclonic Epilepsy whose inclusion in the wider syndrome remains debatable. We have reviewed the literature and present data from six further cases. Prognosis in respect of long term seizure freedom is good with sodium valproate being the most effective medication. However, the cognitive outcome is much less certain with cognitive problems present in one-third of children who have long term follow up. The cognitive outcome in reflex Myoclonic Epilepsy of infancy is normal in all reported cases. The term benign may be appropriately used to describe the Myoclonic seizures but must be used cautiously when counselling families about cognitive outcome. The clinical heterogeneity within this syndrome suggests that there may be a variety of genetic mechanisms that underlie the presentation. Clinicians should distinguish the syndrome of reflex Myoclonic Epilepsy in infancy from benign Myoclonic Epilepsy of infancy and all patients should continue developmental follow up for several years after diagnosis.
J. G. Millichap - One of the best experts on this subject based on the ideXlab platform.
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5,10-Methylenetetrahydrofolate Reductase Deficiency and Myoclonic Epilepsy
Pediatric Neurology Briefs, 2014Co-Authors: J. G. Millichap, John MillichapAbstract:Investigators from the Children's Hospital of Philadelphia, PA, and McGill University, Montreal, Quebec, CA, report an adolescent learning-disabled girl who presented at age 14 years with an Epilepsy syndrome initially diagnosed as juvenile Myoclonic Epilepsy.
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Long-Term Outcome in Juvenile Myoclonic Epilepsy
Pediatric Neurology Briefs, 2012Co-Authors: J. G. MillichapAbstract:Researchers at University of Greifswald, Germany; and Cleveland Clinic, OH, studied the long-term seizure outcome in patients with juvenile Myoclonic Epilepsy (JME) and identified factors predictive of seizure remission.
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Long-Term Follow-Up of Juvenile Myoclonic Epilepsy
Pediatric Neurology Briefs, 2006Co-Authors: J. G. MillichapAbstract:A population of 257 juvenile Myoclonic Epilepsy (JME) patients and family members was prospectively evaluated in a study at UCLA School of Medicine and international centers.
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Prognosis of Benign Myoclonic Epilepsy of Infancy
Pediatric Neurology Briefs, 2005Co-Authors: J. G. MillichapAbstract:Neuropsychological, cognitive, and behavioral outcome was studied in a long-term follow-up of 7 patients with benign Myoclonic Epilepsy in infancy (BMEI) at Universita di Palermo, Italy.
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Genetics of Severe Myoclonic Epilepsy of Infancy
Pediatric Neurology Briefs, 2003Co-Authors: J. G. MillichapAbstract:The role of SCN1A gene mutations in the etiology of severe Myoclonic Epilepsy of infancy (SMEI) was investigated in 93 patients followed at the Hopital Saint Vincent de Paul, Paris, and other centers in France and Italy.
