Electrophysiological study of myoclonic seizures in children

Oguni, Hirokazu; Mukahira, Kyoko; Uehara, Takashi; Matsuzaki, Masunori; Ōsawa, Makiko

doi:10.1016/s0387-7604(97)00579-2

Cited by 8 publications

(6 citation statements)

References 5 publications

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“…Contradictory results regarding the latency study between the myoclonic EMG potentials and corresponding GSW have been demonstrated by computer‐assisted back‐averaging studies, suggesting either a subcortical or cortical origin (Oguni et al., 1997b; Panzica et al., 2001). In JME, both the corticospinal and corticoreticular via reticulospinal pathways may be involved, generating distal–predominant and axial–predominant myoclonic jerks, respectively.…”

Section: Discussionmentioning

confidence: 89%

“…However, there has been no description on the semiologic differences of MS among them (Dravet & Bureau, 2005; Dravet et al., 2005; Guerrini et al., 2005a, 2005b; Thomas et al., 2005), and early diagnosis is often difficult without follow‐up data such as responses to treatment or new appearances of other seizure types. MS themselves are difficult to study in detail because they can be observed over only a limited time, and often occur in uncooperative children (most myoclonic epilepsies begin during the first 5 years of life) (Oguni et al., 1992, 1997a, 1997b; Arzimanoglou et al., 2004). In this study, we retrospectively investigated video‐polygraphs of MS in ILAE‐recognized myoclonic epileptic syndromes to assess whether the semiologic MS differences can provide clues for making accurate syndromic diagnoses.…”

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confidence: 99%

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Differentiation of myoclonic seizures in epileptic syndromes: A video‐polygraphic study of 26 patients

et al. 2009

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SUMMARYObjective: We conducted a video-polygraphic study of myoclonic seizures (MS) in different epileptic syndromes to clarify semiologic and electroencephalography (EEG) differences among them. Subjects and methods: The subjects were 26 children with MS, including benign myoclonic epilepsy in infants (BME) in 10, severe myoclonic epilepsy in infants (SME) in 6, idiopathic epilepsy with myoclonic-astatic seizures (IEMAS) in 4, and juvenile myoclonic epilepsy (JME) in 6. We reviewed the video-polygraphs of MS, including the predominant area of muscle involvement (neck, trunk, and proximal or distal upper extremities), postural changes including astatic falling, and mode of appearance. We also analyzed the frequency of a corresponding generalized spike-and-wave complex (GSW) and the duration of myoclonic electromyography (EMG) activity. Results: A total of 550 MS were documented in the 26 cases. MS manifested with proximal predominance/forward flexion/single occurrence in BME, proximal predominance/forward astatic flexion/single occurrence in IEMAS, proximal predominance/extension/succession in SME, and distal predominance/extension/succession in JME. The median frequency of GSW was 1.5, 1.3, 3.2, and 3.1 Hz, respectively, and the median duration of the myoclonic EMG activity was 387, 587, 81, and 65 ms, respectively. Conclusion: MS in the four different epileptic syndromes show significant semiologic and EEG differences, as well as similarities. Although our study has the limitations of the small number of patients and retrospective methodology, these results should be considered in the classification and differential diagnosis of myoclonic epileptic syndromes.

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Section: Discussionmentioning

confidence: 89%

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confidence: 99%

Differentiation of myoclonic seizures in epileptic syndromes: A video‐polygraphic study of 26 patients

et al. 2009

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“…Myoclonus of cortical origin may be associated with enlarged somatosensory evoked potentials and increased long‐latency reflexes 62. It may also be associated with a brief potential in scalp electroencephalographic activity that is time‐locked to the myoclonic jerk or negative myoclonic relaxation and that can be identified using EEG back‐averaging 62, 63…”

Section: Electrophysiological Studies In Hyperkinetic Impairmentsmentioning

confidence: 99%

Definition and classification of hyperkinetic movements in childhood

et al. 2010

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Hyperkinetic movements are unwanted or excess movements that are frequently seen in children with neurologic disorders. They are an important clinical finding with significant implications for diagnosis and treatment. However, the lack of agreement on standard terminology and definitions interferes with clinical treatment and research. We describe definitions of dystonia, chorea, athetosis, myoclonus, tremor, tics, and stereotypies that arose from a consensus meeting in June 2008 of specialists from different clinical and basic science fields. Dystonia is a movement disorder in which involuntary sustained or intermittent muscle contractions cause twisting and repetitive movements, abnormal postures, or both. Chorea is an ongoing random-appearing sequence of one or more discrete involuntary movements or movement fragments. Athetosis is a slow, continuous, involuntary writhing movement that prevents maintenance of a stable posture. Myoclonus is a sequence of repeated, often non-rhythmic, brief shock-like jerks due to sudden involuntary contraction or relaxation of one or more muscles. Tremor is a rhythmic back-and-forth or oscillating involuntary movement about a joint axis. Tics are repeated, individually recognizable, intermittent movements or movement fragments that are almost always briefly suppressible and are usually associated with awareness of an urge to perform the movement. Stereotypies are repetitive, simple movements that can be voluntarily suppressed. We provide recommended techniques for clinical examination and suggestions for differentiating between the different types of hyperkinetic movements, noting that there may be overlap between conditions. These definitions and the diagnostic recommendations are intended to be reliable and useful for clinical practice, communication between clinicians and researchers, and for the design of quantitative tests that will guide and assess the outcome of future clinical trials.

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“…In contrast, Oguni et al 2 reported a longer EEG-EMG interval of 41 AE 13 ms (mean AE SD) in children with myoclonic epilepsy. In that report, the authors concluded that polysynaptic corticomotor conduction might be associated with the longer interval.…”

Section: Discussionmentioning

confidence: 87%

“…In that report, the authors concluded that polysynaptic corticomotor conduction might be associated with the longer interval. 2 In fact, some studies have provided evidence of polysynaptic conduction in the corticomotor pathway of the SCM. 3 Thus, this unique feature of the SCM muscle may contribute to the longer interval in our patient's focal myoclonus.…”

Section: Discussionmentioning

confidence: 99%