TY - JOUR
T1 - Connectivity measures suggest a sub-cortical generator of myoclonus in Angelman syndrome
AU - Ferlazzo, Edoardo
AU - Franceschetti, Silvana
AU - Gasparini, Sara
AU - Elia, Maurizio
AU - Canafoglia, Laura
AU - Pantaleoni, Chiara
AU - Ascoli, Michele
AU - D'Agostino, Tiziana
AU - Sueri, Chiara
AU - Ferrigno, Giulia
AU - Panzica, Ferruccio
AU - Cianci, Vittoria
AU - Aguglia, Umberto
PY - 2019/12
Y1 - 2019/12
N2 - Objective: The clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients. Methods: We performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus. Neurophysiological investigations included jerk-locked back-averaging (JLBA), cortico-muscular coherence (CMC) and generalised partial directed coherence (GPDC). CMC and GPDC analyses were compared to those obtained from 10 healthy controls (HC). Results: Twenty-four patients (aged 3–35 years, median 20) were evaluated. Sequences of quasi-continuous rhythmic jerks mostly occurred at alpha frequency or just below (mean 8.4 ± 1.4 Hz), without EEG correlate. JLBA did not show any clear transient preceding the jerks. CMC showed bilateral over-threshold CMC in alpha band that was prominent on the contralateral hemisphere in the patient group as compared to HC group. GPDC showed a significantly higher alpha outflow from both hemispheres toward activated muscles in the patient group, and a significantly higher beta outflow from contralateral hemisphere in the HC group. Conclusions: These neurophysiological findings suggest a subcortical generator of myoclonus in AS. Significance: Myoclonus in AS has not a cortical origin as previously hypothesised.
AB - Objective: The clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients. Methods: We performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus. Neurophysiological investigations included jerk-locked back-averaging (JLBA), cortico-muscular coherence (CMC) and generalised partial directed coherence (GPDC). CMC and GPDC analyses were compared to those obtained from 10 healthy controls (HC). Results: Twenty-four patients (aged 3–35 years, median 20) were evaluated. Sequences of quasi-continuous rhythmic jerks mostly occurred at alpha frequency or just below (mean 8.4 ± 1.4 Hz), without EEG correlate. JLBA did not show any clear transient preceding the jerks. CMC showed bilateral over-threshold CMC in alpha band that was prominent on the contralateral hemisphere in the patient group as compared to HC group. GPDC showed a significantly higher alpha outflow from both hemispheres toward activated muscles in the patient group, and a significantly higher beta outflow from contralateral hemisphere in the HC group. Conclusions: These neurophysiological findings suggest a subcortical generator of myoclonus in AS. Significance: Myoclonus in AS has not a cortical origin as previously hypothesised.
KW - Coherence
KW - EEG
KW - Jerk-locked back averaging
KW - Jerks
KW - Polygraphy
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U2 - 10.1016/j.clinph.2019.08.031
DO - 10.1016/j.clinph.2019.08.031
M3 - Article
AN - SCOPUS:85074540326
VL - 130
SP - 2231
EP - 2237
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
SN - 1388-2457
IS - 12
ER -