TY - JOUR
T1 - Different neurophysiologic patterns of myoclonus characterize Lennox-Gastaut syndrome and myoclonic astatic epilepsy
AU - Bonanni, Paolo
AU - Parmeggiani, Lucio
AU - Guerrini, Renzo
PY - 2002
Y1 - 2002
N2 - Purpose: To study the neurophysiologic characteristics of epileptic myoclonus in patients with Lennox-Gastaut syndrome (LGS) and myoclonic astatic epilepsy (MAE). Methods: Three patients with symptomatic LGS (mean age, 15 years ± 4) and three with cryptogenic MAE (mean age, 9 years ± 3) were studied. Temporal relationships between electroencephalographic (EEG) and electromyographic activity were studied by analyzing latencies of EEG activity related to the onset of single myoclonic jerks, by using burst-locked EEG averaging where necessary. Results: LGS: neurophysiologic analysis indicated that jerks and the accompanying premyoclonic spikes showed latency differences between sides (mean ± SD, 18 ± 5 ms for both) with a constant leading side in each patient. The premyoclonic spike latency was 20 ± 10 ms (mean ± SD). Topographic voltage mapping of the premyoclonic spike peak showed a unilateral frontal distribution. MAE: muscles from both sides were activated synchronously, and the EEG correlate was a generalized spike-wave, in which the negative peak of the spike preceded the generalized jerks by 30 ± 2 ms (mean ± SD). Topographic voltage mapping of the premyoclonic spike peak showed a diffuse distribution of the electrical field, predominating over the anterior regions, but not lateralized. Conclusions: These neurophysiologic findings indicate that epileptic myoclonus in LGS originates from a stable generator in the frontal cortex, to spread to contralateral and ipsilateral cortical areas, whereas myoclonus in MAE appears to be a primary generalized epileptic phenomenon.
AB - Purpose: To study the neurophysiologic characteristics of epileptic myoclonus in patients with Lennox-Gastaut syndrome (LGS) and myoclonic astatic epilepsy (MAE). Methods: Three patients with symptomatic LGS (mean age, 15 years ± 4) and three with cryptogenic MAE (mean age, 9 years ± 3) were studied. Temporal relationships between electroencephalographic (EEG) and electromyographic activity were studied by analyzing latencies of EEG activity related to the onset of single myoclonic jerks, by using burst-locked EEG averaging where necessary. Results: LGS: neurophysiologic analysis indicated that jerks and the accompanying premyoclonic spikes showed latency differences between sides (mean ± SD, 18 ± 5 ms for both) with a constant leading side in each patient. The premyoclonic spike latency was 20 ± 10 ms (mean ± SD). Topographic voltage mapping of the premyoclonic spike peak showed a unilateral frontal distribution. MAE: muscles from both sides were activated synchronously, and the EEG correlate was a generalized spike-wave, in which the negative peak of the spike preceded the generalized jerks by 30 ± 2 ms (mean ± SD). Topographic voltage mapping of the premyoclonic spike peak showed a diffuse distribution of the electrical field, predominating over the anterior regions, but not lateralized. Conclusions: These neurophysiologic findings indicate that epileptic myoclonus in LGS originates from a stable generator in the frontal cortex, to spread to contralateral and ipsilateral cortical areas, whereas myoclonus in MAE appears to be a primary generalized epileptic phenomenon.
KW - Back-averaging
KW - Epilepsy
KW - Lennox-Gastaut
KW - Myoclonic-astatic
KW - Myoclonus
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U2 - 10.1046/j.1528-1157.2002.30301.x
DO - 10.1046/j.1528-1157.2002.30301.x
M3 - Article
C2 - 12060020
AN - SCOPUS:0036286644
VL - 43
SP - 609
EP - 615
JO - Epilepsia
JF - Epilepsia
SN - 0013-9580
IS - 6
ER -